GIS Test 3, Chapter 14, Final Review Ch. 9+10, GIS- Networks and Analysis, Terrain Analysis, Chapter 13 and 14, Geodetic Positioning, Quiz 4 - T1, GEOG 201 Midterm Part II, GIS Chapter 4, Digital Planet midterm, Digital Planet Final, NRES312 GIS, Geo...
Radio waves
UHF, VHF, radio (HF), LF, ULF
TIGER files are created and maintained by
US census bureau
Terra is a collaboration of which countries?
US, Canada, Japan
Who launched the first man-made satellite in 1957 to achieve orbit around Earth?
USSR
which out of: UV light, near infrared light, radio waves and microwaves have the shortest wavelength
UV light
On a sketch of the electromagnetic spectrum label the approximate positions of the following spectral regions: UV, visible blue, visible green, visible red, near IR, thermal IR, microwave (wavelength ranges are not required).
UV, b, g, r, nir, tir, micro
When selecting an area to examine using ESRI's business analyst you can...
Use a simple circle around a chosen point, Use network distance in the form of drive times
block
*def:* a flat polygon that has been extruded to transform it into a polygon
8-bit sensor can produce:
0-255 range of brightness values
IKONOS
1st privately launched commercial satellite, 1999
Computer-based mapping and analysis of a location-based data best describes :
GIS
Computer-based mapping and analysis of location based data best describes
GIS
SQL
GIS queries are composed in which computer language
In essence, a texture used in designing a 3D model is just a graphic file
True
Income alone is not a key determinant is ESRIs market segmentation groupings
True
Metropolitan Statistical Areas sometimes cross state lines
True
Most digital terrain models (DTMs) are 2.5D
True
HIRDLS
the High Resolution Dynamics Limb Sounder instrument onboard Aura.
MLS
the Microwave Limb Sounder instrument onboard Aura.
LIDAR
(Acronym for light detection and ranging) A remote sensing technique that uses laser beams to create a digital terrain model [measure distances and reflective surfaces]
NDVI
(Normal difference vegetation index) -primarily used to determine health of vegetation
Accuracy Assessment
(also called contingency table or confusion matrix) -columns represent reference data -rows represent predicted classes
Reflectance
(energy reflected at given wavelength/ energy incident at given wavelength)
offset
*def:* a value applied to an object that is not attached to the ground, but is entirely above ground level
Spectral imaging
- Complete spectrum is collected at every location -Divides into bands beyond (visible: R,G,B)
Ikonos
--Provides commercial images
sources of error for PPP/ RTK
-MAINLY ionosphere delay - multipath - satellite orbit uncertainties - antenna phase center variations
Phototypes
...
Ultraviolet
0.1-0.4 microns
What is the visible spectrum?
0.4 - 0.7 micrometers (blue, green, red)
Sensing in the blue portion of the EM spectrum means sensing energy wavelengths of
0.4 to 0.5 um
What are the basic advantges of API?
1) Improved vantage point 2) Stop action/permanent record 3) broadened spectral sensitivity (filters, electronics for digital) 4) increased spatial resolution 5) better geometric accuracy
What conditions does API need?
1) an illumination source (sunlight) 2) good weather 3) must consider atmospheric affects (dust, humidity, smoke, pollution)
Why do geographers use air photos?
1) map the areal extent of features (deliniation) 2) measure distances/heights of objects (photogrammetry) 3) to record changes over time (temporal)
Image interpretation: 1st order elements
1. Tone (variation from B&W) 2. Color (hue, value, chroma) 3. Resolution (sharply defined image)
Middle Infrared
1.3-3.0 microns
What is the typical minimum population size that is used for a census tract
1200
The vertical accuracy of a LIDAR model of terrain is typically about
15 centimeters
Landsat 7 and 8 satellite has the capability to see the same area on the ground every
16 days
GPS satellites make _________ orbits around the Earth each day.
2
Ephemeris errors typically introduce _______ or so of error. 2 meters 1.5 kilometers 2.5 centimeters 3 feet
2 meters
GPS satellite constellations
27 satellites + 4 spares 6 orbital planes 55 degree orbital inclination orbit radius- 20,200 km
space, control, user
3 GPS segments
LANDSAT 8 multispectral imagery is at what resolution?
30m
In 3D modeling a block has at least...faces
6
In 3D modeling, how many faces does a block have?
6
The highest value for the Sun altitude is ____ while the highest value for the Sun azimuth is ____
90, 360
Ultraviolet light
<0.4 micrometers wavelength range -wavelength is shorter than a normal one -SUNSCREEN is to protect from this light
OLI
the Operational Land Imager, the multispectral sensor that will onboard LDCM
Mutually exclusive
A classification scheme in which each feature only belongs to one category
network datasets
A GIS layer that is a network containing turns, points, street names, etc.
QGIS
A GIS software that can be downloaded for free
Corona
A United States government satellite remote sensing program utilizing film-based camera equipment which was in operation from 1960-1972
Model
A _____ represents, simplifies, or generalizes reality
Radar
A good example of active remote sensing
TIGER Line file
A road file developed by the US govt, traditionally used for geocoding; full nationwide coverage
GRS80
A satellite-determined ellipsoid for the Geodetic Reference System 1980 semi major axis a (m)= 6,378,137 semi minor axis b (m)= 6,356,752 flattening ratio, f= 1/298.57
Band
A set of adjacent wavelengths or frequencies with a common characteristic -a narrow range of wavelengths
Ephermis
A table of the predicted positions 0f a satellite within its orbit for each day of the year, or for other regular intervals
A map of a neighborhood showing land cover types is an example of _________
A thematic map
Map Projection
A translation of locations on the Earth's surface to their corresponding locations on a flat surface
True
A vehicle navigation system that shows the correct entrances and exits off a highway exhibits accurate connectivity
A 1:24000 scale topographic map will show how much geographic area? A. 7.5 minutes of latitude by 7.5 minutes of longitude B. 24,000 feet by 24,000 feet C. 15 miles by 15 miles D. 8000 meters by 8000 meters
A. 7.5 minutes of latitude by 7.5 minutes of longitude
Pre-made 3D objects in SketchUp refer to: A. Components B. Prisms C. Georeferences D. Faces
A. Components
True Color...
All colors in correct color bands (Red in 1, Green in 2, Blue in 3)
ASTER: Temporal Resolution
ASTER is an on-demand sensor
Buffer
All of the following are common overlay methods except
Panchromatic photos absorb color from what portions of the EM spectrum?
All portions of the spectrum (Red, Blue, and Green all at once)
The signals containing information about the satellite's status, orbit, and location are collectively referred to as the
Almanac
Stereoscope
An optical device for viewing stereoscopic photographs
Relief Displacement
Angle of objects is inward or outward due to the placement/location of the object from the principle point.
Citizen Science
Any involvement of the public to help answer science questions with many people -ie: Nature's notebook
What is the name of the EOS satellite whose mission it is to examine the elements in the air, especially the chemistry of Earth's atmosphere?
Aura
What is a panchromatic air photo?
Black and white film is often called this because of its sensitivity to visible light Panchromatic means all-colors
Many 3D models are available to use in Google Earth and SketchUp via the: A. 3D Globe B. 3D Warehouse C. 3D Buildings Layer D. 3D Thematic Mapper
B. 3D Warehouse
Extruding a polygon will turn it into a: A. Block B. Line C. Multipatch D. Wall
B. Block
Imaginary lines on a map that represent areas of constant elevation are: A. Bands B. Contours C. Digital Line Graphs D. Collars
B. Contours
Hertz
the SI unit of frequency, equal to one cycle per second.
In the coordinate system which variable represents elevation
z
Pseudoranges
Base station receives GNSS signals, calculates _________________ to satellites, then determines range errors
Symmetrical difference
Based on areas that do not overlap
Panchromatic Photos...
Black and white photos where light from the blue, green, and red spectrums are combined to make the photos (Also possible: Light from any one wavelength is displayed)
Extruding a polygon will turn into a
Block
1. The art and science of making maps describes a. GIS. b. thematic design. c. cartography. d. map intuition
C. Cartography
A digital terrain model that consists of regularly sampled points of elevation is a: A. DLG B. TIN C. DEM D. TED
C. DEM
Which of the following operations would best allow you to place 3D buildings at their proper height on the terrain (ex: the terrain is 900 ft above sea level, you want the building to sit on the terrain, not float above or below it)?: A. extrusion B. offsetting C. applying base heights D. vertical exaggeration
C. applying base heights
Which of the following does not represent an attempt to make GPS more accurate? NDGPS SBAS CORS PDOP
PDOP
1.023 MHz
C/A code frequency
Canadian Gravimetric Geoid of 2013
CGG2013 stands for what?
canadian geodetic vertical datum of 2013
CGVD2013 stands for what?
What is a spectral band?
Certain set of wavelengths within a set region of wavelengths.
Phase Modulation
Changing the phase of the carrier wave to encode data used to differentiate satellite signals and to provide signal timing information for range measurements
Electromagnetic Energy
Characterized by wavelength, frequency, amplitude, and phase.
10. Which of the following uses a rule-based design for quickly rendering 3D buildings?
CityEngine
CDMA
Code Division of Access
The white, information filled border around a topographic map is known as the ____
Collar
Pre made 3D objects in Google SketchUp are referred to as
Components
Map projections that preserve angles locally
Conformal
Hypsography is the technical term for geospatial data that represents
Contour Elevation
Which of the following uses a rule-based design for quickly rendering 3D buildings? A. SketchUp B. GeoWall C. ArcGlobe D. CityEngine
D. CityEngine
In 3D design, elevation or height values are referred to with the letter: A. E B. H C. Y D. Z
D. Z
Lidar uses which of the following to create a digital terrain model? A. satellite imagery B. radar waves C. GPS D. laser beams
D. laser beams
A digital terrain model that consists of regularly sampled points of elevation is a
DEM
tens of kilometers
DGNSS works very well with base-station to rover seperations of up to __________ ___ _______________
Selective Availability
Describes incorrect data deliberately transmitted from GPS satellites -an international degradation of public GPS signals implemented for national security reasons
DGNSS
Differences between the positions can be attributed to satellite ephemeris and clock errors, but mostly to errors associated with atmospheric delay
Define spectral reflectance
Different wavelengths that an object or feature reflects. This shows different colours.
Landsat 7 carries which of the following sensors?
ETM+
Constellation and Signals
Each GNSS constellation has its own signal frequencies and bandwidths. An antenna must cover the signal frequencies transmitted by the constellation and bandwidth supported by the GNSS receiver.
Endlap
Each vertical aerial photograph overlaps the next by ~60% (stereoscopic overlap)
Gamma radiation
Extremely short wavelengths and VERY DANGEROUS
Which of the following operations would best allow you to model a feature such as creating a footprint of your house and showing the house at the proper height in ArcScene
Extrusion
Radar resolution
Factors that effect radar resolution: 1. Range resolution 2. Azimuth resolution --determined by width of synthesized ANTENA and WAVELENGTH
A KML file is a compressed version of a KMZ file
False
Image interpretation: 2nd order elements
GEOMETRIC ARRANGEMENT OF OBJECTS 1. Size (important discrimination of object / features) 2. Shape 3. Texture (smoothness, roughness) 4. Pattern, vegetation
Sidelap
Flightlines are usually overlapped by 20-30%
Tiff file
For clearer graphics and better resolution, it is better to save your map as a
Gamma Radiation
Form of electromagnetic energy with the SHORTEST wavelength
Air photo aquisition components
Found on the edge of the air photo; date,time, film type, GPS, lens info. Series # example 10-00198 (10=flightline, 198 = # of the photo in that flight line)
The Russian equivalent of GPS is
GLONASS
GLONASS (Russia
GLONASS is operated by the Russian government. The GLONASS constellation consists of 24 satellites and provides global coverage.
A technology that uses signals broadcast from satellites to determine position and navigation on Earth is:
GNSS
Step 1-Satellites
GNSS satellites orbit the earth. The satellites know their orbit ephemerides (the parameters that define their orbit) and the time very, very accurately. Ground-based control stations adjust the satellites' ephemerides and time, when necessary.
Propagation
GNSS satellites regularly broadcast their ephemerides and time, as well as their status. GNSS radio signals pass through layers of the atmosphere to the user equipment.
Computation
GNSS user equipment uses the recovered information to compute time and position.
What is an 'annotated orthophotomap'?
Gives you more geographic information about the area Map makers can overlay conventional map symbols on an orthophoto
GNSS
Global Navigation Satellite System
GPS TIME
Global Positioning System time, is the atomic time scale implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. GPS time was zero at 0h 6-Jan-1980 and since it is not perturbed by leap seconds GPS is now ahead of UTC by 18 seconds.
Seperate Elements of DOP
HDOP VDOP PDOP
Red infrared color indicates...
Healthy vegetation (Reflects more infrared radiation)
Quickbird
Hi-Res B&W and color pictures
Draw a spectral reflectance curve for healthy green vegetation.
High in nir, low in r, b, medium in green
Recreational grade GPS can be described as:
High precision, low accuracy
LIDAR is commonly used in the development of
High resolution DEMs, Improved digital orthophotos, digital flood insurance maps, wetland maps
Which of the following questions are asked on a census short form
How many people are living or staying in this house, is this house owned by you, what is your age, what is your telephone number, what is your sex, are you of Hispanic Latino or Spanish origin
Topology (GIS terms)
How objects are connected to one another independently of their coordinates
Temporal Resolution
How often a sensor records imagery of a particular area
Temporal Resolution
How often you can get another image; revisit time.
What is the 'principal point' of an aerial photo?
If you draw two lines between opposite points using the four fiducial marks, they will intersect at a point called the principal point (the center point) The principal point is the point directly below the camera (the nadir) only when the plane is flying parallel to the ground
Exhaustive (Classification system principle)
Includes whole area/all covers or types
Hierarchical (Classification system principle)
Increases in complexity; collapsible
North
Most maps have a graphical device that looks like a compass pointing in one specific direction, which direction
Within an Active Sensor, energy pulses are transmitted from the...
Instrument to the surface and energy is scattered by the surface and is received by the antenna
TAI
International Atomic Time
IGS
International GNSS Service
IGS
International GNSS service
SI
International System of Units
Ratio Data
Into which category would a person's weight fall
Geospatial data is unique because
It is connected to a real world location
What makes geospatial data unique?
It is connected to a real-world location
According to the lectures what are they key reasons that the census is valuable
It is the only source for demographic data with a wide geographic scope, it is the most reliable and detailed information for describing local areas, it is the most consistent source of time series demographic data available
Standard Untit
Kilo (1000), Mega (1,000,000), Giga (1,000,000,000)
Image interpretation: 3rd order elements
LOCATION / POSITION 1. Site (object + arrangement w/ terrain features --> aspect, topography, vegetation) 2. Association (w/ nearby objects) 3. Height 4 Shadow (calculated by x)
Landsat 1,2,3: Spectral Resolution
Landsat 1,2, and 3 have 5 bands (Green, Red, IR, IR, Thermal) (MSS)
Landsat 1,2,3
Landsat 1,2, and 3 were launched in 1972 MSS
Landsat 1,2,3: Spatial Resolution
Landsat 1,2,3 have a 80m spatial resolution (240m for band 8)
Landsat 1,2,3: Temporal Resolution
Landsat 1,2,3 have a repeat time of 18 days
Landsat 4,5: Spectral Resolution
Landsat 4,5 have 7 bands (blue, green, red, Near IR, Mid IR, Mid IR, and Thermal) (Thematic Mapper TM)
Landsat 4,5: Spatial Resolution
Landsat 4,5 have a 30m resolution for bands 1-5 and 7 and 120m resolution for band 6 (Thermal)
Landsat 7: Spectral Resolution
Landsat 7 has 8 bands (Pan, blue, green, red, near IR, mid IR, mid IR, and Thermal) (Enhanced Thematic Mapper Plus 'ETM+')
Landsat 7: Spatial Resolution
Landsat 7 has a 15m resolution in the Panchromatic, 30mm resolution in the MS, and 60m resolution in the Thermal
Landsat 7: Temporal Resolution
Landsat 7 has a repeat time of 16 days
Landsat 7
Landsat 7 was launched in 1999 ETM+
What is 'overlap' in air photos?
Large scale airphotos are taken along flight lines about 10,000 feet in the air. The flight lines create a 60-80% overlap. duplicated image of the ground in two successive air photos
LIDAR uses which of the following to create a digital terrain model
Laser Beams
Which of the following does LIDAR use to measure terrain?
Laser beams
0.4- 0.7 micrometers of light (400-700 nanometers)
Light that our eyes are used to viewing (Visible light spectrum)
Baseline and Differential Corrections
Like DGNSS, the position accuracy acheivable by the RTK rover depends on, among other things, its distance from the base station referred to as the ____________ and the accuracy of ___________ ______________
High-oblique
Oblique image showing horizon
Flight Lines
Line of flight of a plane taking aerial photos
Example of non-spatial data
List of addresses for a delivery truck to visit
MODIS: Spatial Resolution
MODIS has a 250m, 500m, or 1000m variable spatial resolution for visible/IR
Steps for calculating the scale of an aerial photograph...
Measure from Point A to Point B on the photo in feet (This is the photo distance [PD] / Measure from Point A to Point B in inches on the USGS topo map (This is the Map Distance [MD] / Convert the map distance to actual feet (ground distance (If the USGS topo map has a scale of 1 inch to 2000 feet, the actual ground distance [GD] = MD x 2000 / Photo Scale is PD÷GD
When the GPS signals bounce off objects to arrive later than anticipated, which of the following types of errors is occurring?
Multipath
A remote sensing device simultaneously measuring 7 bands of energy wavelengths would be capable of producing _________
Multispectral imagery
U.S. GPS is called
NAVSTAR
CUASHI hydrologic data source
NSF-funded project involving more than 120 universities Internet-based system for sharing hydrologic data Designed to aid the integration and sharing of disparate hydrologic data Stream gauges Precipitation Basin topography
NOAA
National Oceanic and Atmospheric Administration, records ocean and weather data
USGS hydrologic data source
Nationwide datasets based on 1:100,000, 1:250,000 and 1:1,000,000 maps Data shows large rivers and a limited set of attributes for each river Not hydrologically continuous Best used for cartography, not for stream analysis
The most common consumer of location based services is:
Navigating
50 Hz
Navigation system frequency
What portions of the EM spectrum are represented by the Red, Green, and Blue color bands?
Near Infrared (Put in Red color gun) / Green (Put in Blue color band) / Blue (Put in Green color band) (IF SHOWING CORRECT INFRARED)
NDVI (Normalized Difference Vegetation Index)...
Near Infrared - Red ÷ Near Infrared + R
The energy range of 0.7 to 1.3 micrometers defines which of the following types of energy?
Near infrared
Remote Sensing Definition
Obtaining information about earth's surface from measurements of radiated energy by aircraft or satellite sensors.
The value applied to objects to move them off ground level is the
Offset
Which of the following operations would best allow you to model a feature such as an elevated walkway joining two buildings over a busy city
Offsetting
Imagery that you can see in Google Earth represents:
One snapshot in time from when the image was acquired
complexity of project elements
PRIMARY - tone and colour SECONDARY - size, shape, texture TERTIARY - pattern, shadows HIGHER- site, association
pits
Pits are most commonly a result of data errors Pits in DEM's may be naturally occurring karst/cave systems Flat, glaciated areas Directionality for pits and sinks is all inward, no outward flow
Raster Data
Pixel Data
In the video lectures we listed a number of technologies for the acquisition of 3D data. Which of the following are NOT technologies listed in the lectures for the acquisition or creation of 3D data
Plane Table Survey
What is a spectral reflectance curve
Plots spectrum against relative reflectance for an object, its the objects signature or fingerprint. Shows the proportion of incident energy that is reflected by an object as a function of wavelength.
Vector Data
Point, Line, Area data
The output of a buffer is always a _____
Polygon. -radius is defined and output will be a polygon around the radius
PDOP
Position Dilution of Precision
Spectral Signature...
Profile of spectral information about an object in various portions of the electromagnetic spectrum
Continuous field data is best represented by a:
Raster data model
Continuous field data is best represented by which model in a GIS?
Raster data model
We see the sky as blue in the middle of the day because of
Rayleigh scattering.
Types of scattering
Rayleigh, Mie, nonselective
RTK
Real Time Kinematic
Visible Spectrum
Red, Blue, Green. .4-.7 microns
Atmospheric Windows
Refers to the parts of EMR spectrum that let EMR through effectively, little interference, this makes Remote Sensing possible.
What is being sensed by remote sensing instruments?
Reflected solar radiation
At near IR, vegetation is...
Reflective
Spatial Resolution...
Resolution Type where the smallest "thing" once can distinguish on the remotely sensed image
Color Infrared
Sensitive from 0.35-0.9 microns. Ultraviolet, Blue, Green, Red, Infrared "Color Balance Shift" (not how we perceive world)
Orthochromatic Emulsion
Sensitive to blue and green to ~0.6 microns
Near Infrared Emulsions
Sensitive to blue, green, red, and near-IR to ~0.9 microns
(un)active systems?
Sensor systems 1. photographic amera 2. electro-optical scanners
Hybrid webGIS
Server and client processes can be combined to optimize performance and meet special user needs
location characteristics of an object
Site
physical dimensions of an object
Size
Less detail than
Small scale maps usually show _____ large scale maps
Google docs is an example of:
Software as a service
Reflected (RS Electromagnetic Spectrum)...
Some to all of the energy bounces off the object within the RS Electromagnetic Spectrum (Glass)
4 feet
Suppose a map uses the scale 1:24, and the unit used is the inch. On this particular map, what does 2 inches represent?
XOR
Suppose you want a set of data that eliminates everything that two other data layers have in common, which type of Boolean operator would you use
Orthometric height is the equivalent to
Surface Elevation
Advantages of RS...
Synotpic (regional) view of the landscape / Sense portions of the spectrum not visible to the eye / Repeat cycle (temporal resolution) /
What is the geographical data component of the census data called
TIGER
True
TIGER/line files are often used in address matching
repeating tones
Texture
AND
The Boolean operator used for an intersection query is
CERES
The Clouds and Earth's Radiant Energy System instruments onboard Terra and Aqua.
IRNSS (India)
The Indian Regional Navigation Satellite System (IRNSS) provides service to India and the surrounding area. The full constellation of seven satellites is planned to be deployed by 2015.
In hillshading, the user would set which two parameters
The altitude of the sun and its location in relation to the Earth
Radiant Flux
The amount of radiant energy on to, off of, or through a surface per unit time measured in watts.
Astronomic Longitude
The angle between the plane of the reference meridian and the plane of the local celestial meridian.
Cartography
The art and science of making maps
Relief displacement
The effect seen in aerial imagery where tall items appear to "bend" outward from the photo's center toward the edges
TOADDL
The ending address number on the left side of a street segment in geocode
Roger Tomlison
The father of GIS is
Infrared
The portion of the electromagnetic spectrum with wavelengths between 0.7 and 100 micrometers
Geocoding
The process of matching a typed description like 114 Maple Lane, Smithville, NY to a specific location or set of coordinates is called
What is 'photogrammetry'?
The process of obtaining measurements from aerial photos. This can be used for determining things like height and depth of objects
Atmospheric Correction
The process of removing the effects of the atmosphere on the reflectance values of images taken by satellite or airborne sensors.
The Electromagnetic Spectrum
The range of all possible frequencies of electromagnetic radiation
<>
The relational operator for "not equal" is
Remote Sensing
The science and art of obtaining info about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation -primarily senses radiation that is emitted or reflected by the earth's surface or from the atmosphere
Radiometric Resolution
The sensitivity of a sensor to differences in signal strength. Expressed in 'bits'. Higher resolution increases the probability that differences in wavelength will be sensed accurately.
Why do panchromatic air photos need a UV haze filter?
The shorter near ultraviolet wavelengths are scattered by the atmosphere, requiring a UV haze filter to to be placed over the camera lens to increase clarity of the photos.
Cartographic generalization
The simplification of representing items on a map is referred to as
ZIPL
The zip code for the left side of a street segment in geocode
Only __________ energy is directly related to the sensation of heat
Thermal infrared (IR)
How many points of reference (satellites) are required for you to find your exact location on Earth?
Three
Basic Idea of GPS
To have at least 4 satellites above the horizon available 24 hours everywhere on the earth. In principle, the three- dimensional coordinates of the receiver's antenna can be derived from three observed distances
Dissolve
To simplify a dataset
grayscale levels or ranges of color for objects
Tone
TIGER stands for
Topologically Integrated Geographic Encoding Referencing
When light strikes an object, it is either...
Transmitted, Reflected, or Absorbed (Or a combination of each)
All GIS data are models:
True. (representations of real-world phenomena)
VDOP
Vertical Dilution of Precision
The geospatial analysis tool used to calculate a cell phone coverage map
Viewshed Calculation
Google Earth is an example of a
Virtual Globe
Our eyes are sensitive to viewing which wavelengths of light?
Visible 0.4 to 0.7 um
Raster
What type of data is NLCD
Network
Which term is best defined as a series of junctions and edges connected together for modeling geospatial concepts such as streets
Side lap
a 15-20% side-overlap between flightlines
junctions
a network component that focuses on impedances at intersections, such as stop signs & traffic lights or restrictions e.g. no right turns
links
a network component that focuses on physical distances or impedances such as one-way streets, speed limit
PPP
a positioning technique that removes or models GNSS system errors to provide high level of position accuracy from a Single receiver
RTK
a technique that uses Carrier- based ranging and provides ranges (positions) that are orders of magnitude more precise that those of code- based positioning
spectral signature
a unique identifier for a particular item, generated by charting the percentage of reflected energy per wavelength against a value for that wavelength.
micrometer
a unit of measurement equal to one -millionth of a meter. abbreviated um.
8. A graphical representation of the equivalent distances on a map can best be shown with a a. scale bar. b. north arrow. c. type. d. legend.
a) scale bar
Non-spatial data in a GIS are referred to as: a. Attributes b. Tables c. Points d. Layers
a. Attributes
UT1
also known as astronomical time or solar time, it refers to the Earths rotation. It is used to compare the pace provided by TAI with the actual length of a day on earth
vertical photo
an aerial photo in which the camera is looking straight down at a landscape.
address matching
another term for geocoding
Geoprocessing describes
applying an action to one dataset that results in a new dataset being creating
Non-spatial data in a GIS are referred to as
attributes.
29. Setting up the components of an address in a regular format describes a. parsing. b. standardization. c. linear interpolation. d. connectivity.
b) standardization
Compass
china's GNSS currently in development
advantage of RTK
compared to a post- processing approach is the fact that one is able to check their quality of position online. allowing for better efficiency
8. Premade 3D objects in SketchUp refer to:
components
GPS user segment
comprised of both civilian and military users worldwide, acquires signals sent from the NAVSTAR satellites with GPS receivers - the GPS receiver - with received signals and information stored internally, the receiver can calculate its own position on earth
Geocoding
converts aspatial data to spatial data
an early satellite remote sensing program that used film for taking images was
corona
6. A graphical representation of the orientation of the map can best be shown with a a. label. b. legend. c. scale bar. d. north arrow.
d) north arrow
14. Which of the following data classification methods uses the average distance to the mean value of the dataset in determining class break levels? a. Equal interval b. Quantiles c. Natural breaks d. Standard deviation
d) standard deviation
Site suitability analysis
determines which areas are useful or not in spatial analysis
Atomic Clocks
deviate only 1 second in up to 100 million years used to determine international atomic time
Trimble R8
dual frequency geodetic receiver, could be used for static observations
(P) code
encrypted precision
pan-sharpening
fusing a higher-resolution panchromatic band with lower-resolution multispectural bands to improve the clarity and detail seen in the image.
NDVI is primarily used to determine
health of vegetation
plan curvature
index of surface shape at right angle to profile curvature
profile curvature
index of surface shape in the steepest downhill direction
advantage of PPP
it is an absolute mode only data from a single receiver are needed in order to compute the coordinates with a cm- resolution is good in regions where no geodetic reference stations are available
Why, when comparing images from different years, it is important to try and have the images coincide on the day and month of acquisition as closely as possible?
it minimizes differences, effects, and influences on the data.
How can API make an effective contribution?
it must yield information which is CONSISTENT, RELIABLE, and COST EFFECTIVE.
Geoid
level surface that approximates sea level
Ionosphere delay
major error is GPS
Photogrammetry
making maps using aerial photos, science of measuring geometry from images
P-code
modulated on L1 and L2 and has a frequency of 10.23 MHz - Approx 29.3 m wavelength and a repetition sequence of 266 days, serves primarily for precise navigation and is reserved for authorized users
Are there jobs?
most of the new jobs are digital. Some companies specialize in API (JD Mollard and Ass.). Many applications are now digital using digital air photos and satellite imagery (cheaper, faster, more consistent information - less human error)
Panchromatic Film
most used, produces gray tones recognized by humans
A major road (such as Virginia Beach Blvd) would be represented in a GIS as
multiple records, with each representing one piece of the road
In aerial photography, the spot directly under the camera is called
nadir
TIGER files does not contain which information
number of houses per street
disadvantage of RTK
one needs a link for for transmitting the data of the reference station to rover the coordinates of the reference station have to be known
In the vector data model, all items are represented as
points, lines, and polygons.
Vector data model
points, lines, polygons
Carrier Based technique
positioning technique required for surveying or high precision. RTK AND PPP are examples orders of magnitude more accurate than code based GNSS
PPP
precise point positioning
a few meters
precision of code based positioning techniques
Microwaves fall between:
radio waves and infrared
IGS
responsible for determining the broadcast ephemeris this is done by monitoring the satellites using ground control stations around the world the uploaded broadcast ephemeris is uploaded to the satellites every couple of house (keplerian elements) accuracy of broadcast 5-10 m
1 to 10 m
single frequency receiver accuracy? typically a single frequency receiver only uses the L1 band (C/A code)- fixes errors that are easily rectified, but cannot correct for the information of the atmosphere at the time of acquisition
The "information" being handled by GIS refers to
spatial information
The ground size of one pixel's worth of imagery is a measure of
spatial resolution
the ground size of one pixel's worth of imagery is a measure of
spatial resolution
the size of the area on the ground being represented by one pixel's worth of energy measurement is
spatial resolution
What is colour?
specific wavelengths of light that we observe that are reflected but not absorbed by an object.
a file containing line segments representing roads is a
street centerline file
a tool used for viewing imagery at a particular location on a road is
street view
How does this assertion apply, or not, to a supervised classification?
supervised classification
The measurement of how much ground the satellite can image during one pass is called:
swath width
aerial photography
taking photographs of objects on the ground from an airborne platform.
How often a satellite can return to image the same area on the ground is a measure of that sensor's
temporal resolution
SLC
the Scan Line Corrector in the ETM+ sensor. Its failure in 2003 causes landsat 7 ETM+ imagery to not contain all data from a scene.
P code
the digital code broadcast on the L1 and L2 frequencies which is accessible by the military
MSS
the multi-spectral scanner aboard Landsat 1 through 5
ALI
the multispectral sensor onboard EO-1.
NDGPS
the national differential GPS, it consists of ground based DGPS beacons around the us
channels
the number of satellite signals a GPS unit can receive (the number of satellites the receiver obtain signals from at one time)
spectral reflectance
the percentage of the total incident energy that was reflected from that surface.
Landsat 7
the seventh Landsat mission launched in 1999 whcih carries the ETM+ sensor.
minimum condition on the deviations
to give a "refined" definition at the cm level accuracy of the Geoid. By applying __________________ between MSL and the Geoid, the Geoid could be defined as the equipotential surface which best fits MSL at a certain epoch
off-nadir viewing allows a sensor
to image locations not directly under the sensor
the greyscale levels or intensities of particular colors in an aerial image refers to
tone
tone and colour
tone = the brightness of the object on the photo, colour = the RGB method describes the intensity of each of these three colours
The number of units to travel along a link of a network is
transit cost
EOS: ASTER
"Advanced Spaceborne Thermal Emission and Reflection Radiometer" Sensor on EOS satellites
NOAA AVHRR
"Advanced Very High Resolution Radiometer" On NOAA-15 to 18
EOS
"Earth Observational Satellite" Two satellites (AM, PM) Instruments to replace NOAA MODIS and ASTER sensors
GOES
"Geostationary Operational Environment Satellite" GOES 8-10 have 5 band spectral resolution, used for Earth surface temperatures and atmospheric conditions.
EOS: MODIS
"MODerate resolution Imaging Spectrometer" Sensor on EOS satellites.
coarse acquisition C/A code
(freely available to the public)
IR
(infrared) the portion of the electromagnetic spectrum with wavelengths between 0.7 and 100 micrometers
MIR
(middle infrared) the portion of the electromagnetic spectrum with wavelengths between 1.3 and 3.0 micrometers
NIR
(near infrared) the portion of the electromagnetic spectrum with wavelengths between 0.7 and 1.3 micrometers.
TIR
(thermal infrared) the portion of the electromagnetic spectrum with wavelengths 3 and 14 micrometers.
LiDAR / ALS
- Airborne Laser Scanning - an active remote sensing sensor that measures distance with a reflected laser light - Light Detection and Ranging (laser radar) - remote sensing method --uses light, in the form of pulses to measure ranges --point clouds, builds surface models (DEM) --PROS: high resolution data, 3D info, precise topographic data --CONS: expensive and not available everywhere
Network RTK
- based on the use of several widely spaced permanent stations - positioning from the permanent stations is regularly communicated to a central processing station - on demand from RTK user terminals, which transmit their approximate location to central terminal, CS then calculates and transmits correction information or corrected position to the RTK user terminal - Benefits include reduced number of RTK base stations -Data may be transmitted over cellular radio links or other wireless medium
Satellite Terra Earth-Observing System (EOS)
- carries 5 sensors to study atmosphere, land, ocean, life, radiant energy (light and health -RE.A.L.L.O - ASTER, CERES, MISR, MODIS, MOPITT
Leap Seconds
- every now and then is added to UTC- universal coordinated time, in order to synchronize clocks worldwide with the Earth's ever slowing rotation -before the difference between UTC and UT1 reaches 0.9 seconds _______ are added to the UTC - by adding the ________ to the time count, our clocks are effectively stopped for that second to give Earth an opportunity to catch up - _______________ that are upcoming are announced by the IERS in paris france
TAI
- is a time scale that used the combined output of some 400 highly precise atomic clocks. tells us the exact speed at which our clocks should tick
RTK breakdown
- requires both base and rover - Communication link between base and rover - offers highest accuracy
GPS control segment
- responsible for maintaining the operation of the GPS satellites, consists of the master control station (Colorado Springs) - 5 globally distributed monitoring stations
Remote sensing
--Collecting landscape data without direct physical contact. --Performed with Orbital (satellite) or suborbital (aerial) platforms. --Expand spectral range - measures electromagnetic radiation to detects light from wavelength (light) outside of human eyesight
DEM
--Digital Elevation Model --Made from LiDAR --Best example: Terra
Stereoscopy
--Needed for aerial imagery --Uses binocular vision for observation of overlapping photographs --ex normal eyesight --related to point scale, vertical photograph @ different elevations have different scales, stereoscopy reconciles w/ overlapping
Landsat
--Type of satellite (active) --8 in total --FREE data can be viewed through USGS "EarthExplorer"
GeoEye
--World's HIGHEST RESOLUTION and most accurate commercial Earth-imaging satellite
Spectral resolution
--different instruments record different bands on the EMS --the number and size of the bands which can be recored by a sensor determine an instruments SPECTRAL RESOLUTION ---small #, wide bands = POOR resolution ---large #, short bands = HIGH resolution
Spatial resolution
--measurements of the MINIMUM DISTANCE BETWEEN 2 OBJECTS that will allow them to be differentiated from one another in an image
Electromagnetic spectrum
--range of wavelengths electromagnetic radiation extends --visible spectrum is small --near infrared spectrum: NAIP Imagery --> 4th Band is not visible; we use the false coloring in order to identify vegetation type GREEN (lush) YELLOW (dry)
Stereoscopic
-By overlapping images of 2 images a 3 dimensional image can be obtained
Data manipulation errors include:
-Coding and topological mismatch error -Vector to raster conversion error
Aerial photographs are used for
-Deliniating stand boundaries -Species composition -Volume -Tree density
Gray levels
-Diff. species reflect sunlight differently -Coniferous trees usually darker
Desired crowd for crowdsourcing:
-Diversity of opinion -Independence -Decentralization -Aggregation
Ephermis
-Error which means the correct satellite position isn't being sent -Can result in 2 meters of GPS accuracy
3 attributes of an object to asses information
-Gray levels -Texture -Structure
High resolution
-HIGHLY detailed -small geographic area
Relief displacement
-Higher an object is above the ground more displaced radially outward from center of airphoto -Verticle structures appear to lean away from center of photo -Used to measure height
Advantages of mirror stereoscopes
-Larger areas can be viewed -Height measurements are more precise
Examples of web GIS applications:
-Maps displayed on a website -Dynamic web applications that can track and map movement in real time -Navigation tools that map out driving routs (Mapquest)
Air photo pictures must...
-Overlap by 50% -Sidelap by 25%
Structure
-Shape of an object -Rectangular shapes agriculutral fields etc.
Texture
-Small scale variation in gray levels -Old growth heterogenous stands have high texture -Even aged stands have less texture
Height measurements can be used only if
-The ground is visible (must measure the height of one point to another)
BAD crowd for crowdsourcing:
-Too homogenous -Too centralized -Too divided/isolated -Too imitative -Too emotional
Approach to stereoscopy
-Use 4 fiducial marks in corner of the airphoto or at midpoint of each of the edges to mark center in each air photos -Center is called principle point (pp) -Identify corresponding principle point (CPP) or location of PP of the neighboring airphoto on the photo of interest -Draw a line between PP and CPP on each airphoto
Universal Time UT1
-also known as astronomical time, refers to the earths rotation. It is used to compare the pace provided by TAI with the actual length of a day on Earth
GNSS FACTS! control segment
-comprises of a ground- based network of master control stations, data uploading stations and monitor stations - in the case of GPS, two master control stations (primary+ backup), 4 uploading stations and 16 monitor stations, located worldwide
Sources of Error in geospatial data:
-data collection and input -human processing (misinterpretation) -actual changes (natural changes, river courses) -data manipulation (coding and topological mismatch errors) -data output (scaling accuracies)
Vertical Earth Datums
-define elevations - take into account a map of gravity anomalies between the ellipsoid and the geoid (eg NAVD88)
Low resolution
-only coarse features can be observed in the image -large geographic area
GNSS FACTS! space segment
-orbit about 20,000 km above the earth -each GNSS system has its own "constellation" of satellites, arranged in orbits to provide desired coverage -each GNSS satellite constellation broadcasts a signal that identifies it and provides its time, orbit and status
Internet Exchanges
-where the big networks connect to each other (peering) -Facebook, Netflix -largest ones are in Europe
Identify 3 differences between a supervised and an unsupervised classification. For each difference be sure you state its consequence for both supervised and unsupervised classification.
...
Name one resampling method commonly used during geometric correction. List one advantage and one disadvantage of that method.
...
Under what conditions do remotely sensed images need to be radiometrically corrected?
...
Which of vegetation, soil, and water have the highest and lowest reflectances in the visible portion of the spectrum?
...
Which of the following file extensions is not associated with a shapefile?
.aux (.shp, .shx, and .dbf are all shapefile extentions)
Sensing in the "visible" portion of the EM spectrum means sensing energy wavelengths of
0.4 to 0.7 um
Blue
0.4-0.5 microns
our eyes are sensitive to viewing what wavelengths of light?
0.4um - 0.7um
Sensing in the green portion of the EM spectrum means sensing energy wavelengths of
0.5 to 0.6 um
Green
0.5-0.6 microns
Sensing in the "red" portion of the EM spectrum means sensing energy wavelengths of
0.6 um-0.7 um
Red
0.6-0.7 microns
Near Infrared
0.7-1.3 microns
For data in the National Elevation Data set associate the data type with the nominal post spacing
1 arc second: 30 M post spacing 1/3 arc second: 10 M post spacing 1/9 arc second: 3 M post spacing
What are the benefits of Remote Sensing
1) high information content 2) more economical than surveying large areas (still requires field work for accuracy assessment) 3) stereo viewing 4) Experimental design control by you
How do you measure parallax?
1) identify the PP and the conjugate PP in the stereo pair 2) then we line them up in a straight line 3) measure the distance between the y-axis line and the feature (if you measure on the left side of the axis you get a negative number)
Three types of air photos
1) vertical (used for photogrammetry) less than 3degrees from nadir. 2) High Oblique - can see sky or horizon in the photo 3) Low Oblique - cannot see the sky in the photo
History of remote sensing
1. Airborne sensors (reconnaissance AIRCRAFT) 2. Satellites (landsat, quickbird, geoeye, ikonos)
Why would anyone want to spend money on remote sensing images when there are images out there for free?
1. An image may be needed for a specific time 2. Depends on the type of imagery needed
Three important features of a geographic database:
1. Attributes (what is at the location) 2. Location 3. Topology (Relationship with neighbor)
Factors to consider when choosing a GNSS antenna include
1. Constellation and Signals 2. Antenna Gain 3. Element Gain 4. antenna beam width and gain roll off 5. Phase Center Stability 6.Application
Advantages of remote sensing over other methods of data collection. eg. overhead view vs ground view.
1. Covers greater area, so more context and better perspective. 2. easy to measure distance 3. sight not limited by terrain
1. The end of Selective Availability allowing for in-car navigation 2. Constellations of the various GNSS 3. The Control Segment of GPS - monitoring the health of the satellites 4. Accuracy, Privacy, and Applications 5. How Pseudorange and Trilateration help determine our location A. Todd Humphreys on GPS B. GNSS in 2013 C. Smartphone Lesson D. PC Mag E. Air Force Space Command
1. D 2. B 3. E 4. A 5. C
Types of LiDAR systems
1. DISCRETE-RETURN - system records specific values for each pulse downward (first, middle, last pulse recorded) --first pulse: not ground --second pulse: typically ground 2. WAVEFORM- collects continuous record of pulse returns
Steps to using Remote Sensing Data
1. Define information 2. Collect data 3. Data analysis 4. Verification of analysis 5. Sharing results 6. Taking action
How can EMR interact with surface objects?
1. Diffuse scattering (diffuse reflection) - energy scattered in all directions. 2. Specular reflection - large amount of energy is directly reflected off the objects surface (hot spots). 3. Transmitted - energy is transmitted through the object(s). 4. Absorbed - energy is absorbed (ie photosynthesis). Air Photo Interpretation - air photographs record the reflected EMR (diffuse scattering and specular reflection). This is the same for satellite/airborne digital imagery.
List ways in which remote sensing images differ from maps
1. Display different information, such as vegetation health 2. Maps are labeled ex. roads, elevation
what are some applications of GPS
1. Emergency response 2. farming 3. forensics 4. public utilities 5. transportation 6. wildlife management
Disadvantages of remote sensing over other methods of data collection. eg. overhead view vs ground view.
1. Interferance: atmosphere, tree canopy, clour cover, etc. 2. Limited detail 3. Limited time frames highly dependent on weather conditions
The City of Regina is planning to build a major multi-modal transportation hub to the west of the airport. This hub will consist of significant rail and road transport infrastructure and associated office and warehouse space. What sensors would provide the data to best suit their needs for planning construction? Why?
1. Landsat 8 - OLI sensor - would proviide an overall perspective, general overview. 2. Quickbird - Quickbird sensor - more spatial resolution, so more details about the site.
3 common applications for remote sensing imagery?
1. Monitoring vegetation health 2. Management of land use 3. Comparing land before and after an event. ex: Chernobyl, volcano eruption.
Three basic types of models:
1. Physical 2. Idea (theoretical, empirical, mechanistic) - based on observations 3. Computer
Electromagnetic spectrum- order from least dangerous to most dangerous (longest wavelengths to shortest wavelengths)
1. Radiowave 2. Microwave 3. Infrared 4. Ultraviolet 5. X rays 6. Gamma rays
Why did these things (EMR) evolve on our planet?
1. Region of maximum sun putput (most energy to work with) 2. Atmospheric windows (visible is a region of high transmission)
Popular myths of remote sensing, BUSTED
1. Satellite based remote sensing has sufficient resolution 2. 90% lvl of confidence for accuracy of satellite 3. Satellite remote sensing images are cheaper than aerial photographs 4. visual interpretation is valuable
What are 4 types of image resolution that we are concerned about when interpreting remote sensing data? For each resolution type, give one example of an actual resolution value from a common remote sensor. You may use the same or different sensors for each value.
1. Spatial - size of each pixel. ex. OLI on Landsat 8 has a 30 m spatial resolution 2. Spectral - number of bands being measured. ex. OLI on Landsat 8 has 8 bands 3. Temporal - time satellite takes to acquire image of same ares. ex. Landsat 8 has 16 day temporal resolution 4. Radiometric - precision of sensitivity of measurements; how fine measurement scale is. ex.
finding your position on the ground with GPS relies on three separate components all operating together
1. a space segment 2. a control segment 3. a user segment
describe what a z-value (vertical dimension) means in the context of geospatial data
1. height of an object above whatever surface it's standing on THUS based on a location (geospatial data)
What are the 3 basic steps of digital image analysis? List one procedure which is commonly used from each step.
1. image correction 2. image enhancement 3. classification
What are the BASIC ELEMENTS of API
1. tone and colour 2. Shape 3. Pattern 4. Size 5. Shadows 6. Texture 7. site 8. association
extrusion
1.*def:* the extension of a flat object to have a z-value 2. extruding a polygon will transform it into a block 3. ex: if you know the building is x feet high and only have the footprint, you can extend it to the given height
L5
1176.45 MHz available beginning with Block IIF satellites, has begun broadcasting CNAV messages The benefits of the_____ signal include meeting the requirements for critical safety-of-life applications such as that needed for civil aviation and providing: Improved ionospheric correction. Signal redundancy. Improved signal accuracy. Improved interference rejection.
L2
1227.60 MHz modulated by the P-code and, beginning with the Block IIR-M satellites, the L2C (civilian) code. L2C has begun broadcasting civil navigation (CNAV) messages.
L1
1575.42 MHz modulated by the C/A code (Coarse/Acquisition) and the P-code (Precision) which is encrypted for military and other authorized users.
landsat 8 sensor has the capability to see the same area on the ground every
16 days
Speed of light
186,00 miles/sec in vacuum
When was NASA established?
1958
3 significant developments in the history of remote sensing and why were they significant?
1972: Earth resources technology satellite launch with RBV and MSS (4 bands, 80m spatial resolution) 1980s: Landsat 4 5 6 carrying TM (7 bands, 30m spatial resolution)
In which year was the first GPS satellite launched?
1978
Place in order from large geographic unit to smallest
1: United States 2: Region 3: State 4: County 5: Place 6: Tract 7: Block group 8: Block
Using the notation that is used by ArcGIS associate the direction with the aspect value
1: north 89: east 182: south 265: west
What is the typical scale for forestry?
1:10 000 to 1:20 000
5 STEPS OF GNSS
1:Satellites 2: propogation 3 reception 4:computation 5:application
Microwaves
1mm - 1 meter
describe the difference between 2.5 and true 3D spatial data
2.5 D has only 1 Z value per xy point, while 3D can have multiple
Only being able to show one elevation value for each x/y pair of coordinates is a conceptualization of a
2.5 dimensional model
What is the minimum number of satellites required for a constellation?
24
Use of WAAS can reduce position error within:
3 meters
Thermal IR
3.0-5.0 microns AND 8.0-14.0 microns
7. Many 3D models are available to use in Google Earth and SketchUp via the:
3D Warehouse
Use of WAAS can reduce position error to within
3meters
The minimum number of satellites needed to get a good location and elevation from GPS is _____
4
What is a multispectral scanner?
4 bands
What is the optimum population size for a census tract
4000
A 1:24000 scale topographic map will show how much geographic area
7.5 minutes of latitude by 7.5 minutes of longitude
SRTM resulted in a highly accurate digital elevation model of about what percentage of Earth?
80
Ionospheric Delay
80 km and 600 km above the earth. This layer contains electrically charged particles called ions. These ions delay the satellite signals and can cause a significant amount of satellite position error (Typically ±5 metres, but can be more during periods of high ionospheric activity). varies with solar activity, time of year, season, time of day and location.
What is the nominal maximum population size of a census tract
8000
What is a channel on a remotely sensed image?
A channel refers to a spectral band in the visible spectrum. coloured layer.
Differential Correction
A class of techniques used for improving GPS accuracy by comparing measurements taken by two or more receivers (one stationary, one mobile) -can correct pretty much every other type of error EXCEPT multipath error
Continuous Field View
A conceptualization of the world in which all items vary across Earth's surface as constant fields, and values are available at all locations along the field *Real world phenomena continuously vary -Example: temperature, atmospheric pressure, elevation
True
A good model each edge is considered a separate entity
Which of the following is an example of a thematic map?
A map of a neighborhood showing land cover types
Thematic map
A map that shows the percentage of population in each U.S. state that was born in a different country is an example of a
IFOV
A measure of the spatial resolution of a remote sensing imaging system. Defined as the angle subtended by a single detector element on the axis of the optical system.
True color (composite image)
A photo in which there are three bands, each representing either red, green, or blue light (natural color)
What is a CIR air photo?
A photo made with CIR film which was made during WW2 and is sensitive to near-infrared light and visible light. NIR reflection is seen as red on the photo It could be used to detect camouflage or healthy vegetation
More clarity
A photo of 300 DPI will have _____ than a photo of 72 DPI
Network
A series of interconnected links and junctions representing routes for locating spatial features or travelling from one location to another.
Metadata
A set of information about your data found in a separate file is called
Algorithm
A set of steps to solve a problem
Map algebra
A site suitability analysis where two or more raster layers are added together is an example of
What is the difference between a vertical aerial photo and an oblique aerial photo?
A vertical aerial photo is taken with the camera looking directly down at the landscape In an oblique photo, the camera is tilted so instead of looking directly down at the landscape, it is looked at an angle.
Scale bar
A visual element on a map shows that 1 centimeter is the equivalent of 40 miles, what element are you looking at
The grading system with a better "radiometric resolution":
A-F (In contrast to pass- fail)
What is the organization of satellites called that serves as the Afternoon Constellation?
A-Train
Small scale maps would use: A. a wider contour interval than a large scale map B. a narrower contour interval than a large scale map C. the same contour interval as a large scale map D. no contour intervals due to the small scale of the map
A. a wider contour interval than a large scale map
Viewing an image that is offset in both the color red and the color blue that enables a "3D" style effect is an example of: A. Anaglyph B. GeoWall C. Stereovision D. CityEngine
A. anaglyph
A DSM can be used to determine which of the following: A. building heights B. the types of leaves on trees C. the health of vegetation D. sub-surface soil types
A. building heights
Which of the following operations would best allow you to model a feature such as creating a footprint of your house and showing the house at the proper height? A. extrusion B. offsetting C. applying base heights D. vertical exaggeration
A. extrusion
A 3D-style choropleth map is a: A. prism map B. smartmap C. raised poly map D. omni-theme map
A. prism map
advantages of using a satellite instead of an aircraft?
A. satellites are constantly orbiting Earth and taking images B. satellites can image a much larger area than a single aerial photograph can C. satellites provide global coverage
A SRTM performed which of the following? A. used radar waves from space to map the terrain surfaces of the Earth B. used radio waves from space to create a full three-dimensional model of the Earth C. used both radar and sonar to create a map of the Earth's surface (and the objects on the surface) D. used radar to map the heights of the oceans to create a new permanent vertical datum
A. used radar waves from space to map the terrain surfaces of the Earth
The SRTM performed which of the following: A. used radar waves from space to map the terrain surfaces of the Earth B. used radio waves from space to create a full three-dimensional model of the Earth C. used both radar and sonar to create a map of the Earth's surface (and the objects on the surface) D. used radar to map the heights of the oceans to create a new permanent vertical datum
A. used radar waves from space to map the terrain surfaces of the Earth
ASTER: Spectral Resolution
ASTER has a 14 band spectral resolution (3 visible/IR, 3 SWIR, 5 TIR) Geological applications.
ASTER: Spatial Resolution
ASTER has a spatial resolution of 15m in the visible, 30m in the SWIR, and 90m in the TIR
NOAA AVHRR: Spectral Resolution
AVHRR has 5 bands. Provides regional information on vegetation, condition and sea-surface temperature
AVHRR: Spatial Resolution
AVHRR has a spatial resolution of 1.1km
AVHRR: Temporal Resolution
AVHRR has a temporal resolution of 2 time per day
Ephemeris error can result in what level of error in GPS accuracy?
About 2 meters
Energy that is trapped and held by a surface has been:
Absorbed
What is 'remote sensing'?
Acquiring data about the reflection of light energy off of a target by a device a considerable distance away from the target from an aircraft or spacecraft
Examples of remote sensing methods:
Aerial photography, radar, and satellite imaging
Human population has led to a substantial expansion in what land use?
Agriculture
Union
An OR Boolean query results in a(n)
Buffer
An area of spatial proximity around a point (GIS operation)
Which of the following operations would best allow you to place 3D buildings at their proper height on the terrain
Applying base heights
What is the name of the EOS satellite whose mission it is to monitor Earth's water cycle?
Aqua
The current version of the "A-Train" consists of
Aqua, Aura, Calipso, and Cloudsat
Which of the following programs is used for analyzing 3D data on a local scale only
ArcScene
What are 'fiducial marks' on an air photo?
Are a way to find the photo center, fiducial marks are placed at the midpoint of each edge Small registration marks exposed on the film edges of a photograph
Raster data model
Areas are modeled using equally spaced and equally sized grid cells
geocoding
Assigning spatial locations of features using relative locations recorded in tabular format and then plotting the location of the spatial features along a network
relating an object to other nearby features
Association
The current generation of topographic maps produced by the USGS are: A. Printed 1:240000 topoquads B. GeoPDF versions of US Topos C. High resolution DRG products D. 3D contours available via a mobile app
B. GeoPDF versions of US Topos
KML and KMZ files are the native file formats used to work with 3D objects in: A. SketchUP B. Google Earth C. ArcScene D. CityEngine
B. Googe Earth
KML and KMZ files are the native file formats used to work with 3D objects in: A. SketchUp B. Google Earth C. ArcScene D. CityEngine
B. Google Earth
In hillshading, the user would set which two parameters: A. the vertical datum and the grid cell resolution B. the altitude of the sun and its location in relation to the Earth C. the vertical accuracy of the model and the steepness of the terrain D. the angle of the suns rays and the vertical exaggeration of the model
B. the altitude of the sun and its location in relation to the Earth
BeiDou (China)
BeiDou is the Chinese navigation satellite system. The system will consist of 35 satellites. A regional service became operational in December of 2012. BeiDou will be extended to provide global coverage by end of 2020.
In the Fayetteville AR area the geoid is
Below the ellipsoid and below the ground surface
Ecosystem services
Benefits that ecosystems supply humans
terrain analysis calculations
Best-applied to raster data Based on cell values assigned in a regular grid Applies Z-values to X-Y planar coordinates Typically use neighborhood operations to define angle and orientation of lines Specific mathematical operations applied to a moving window Use analyses to define normal vectors, at 90° to ground surface, and relative Z-values
Types of film
Black and white (panchromatic), colour (3 layers), colour infrared (CIR), black and white infrared (BWIR). Digital imaging done in some other parts of the EM spectrum (UV, microwave)
The result of an extrusion is a
Block
What is the atomic or most basic geographical unit used in the census
Block
Radar vs. LiDAR
Both ACTIVE systems: generate energy signal and energy signal returned --Radar - radio detection (beam energy through antenna) --LiDAR - light detection
Panchromatic aerial photography uses...
Broad cover types (Forest / Agriculture / Urban / Etc.) / Legacy: Often older photographs are only available as Panchromatic
An area of spatial proximity around a point refers to which GIS operation?
Buffer
Polygons
Buffers created around line features will result in
Describe (what colour is it?) and explain (why is it that colour?) the appearance of commercial / industrial areas on a true colour composite image of Regina in summer.
Buildings are white/light grey because the material is reflecting all or most of the visible spectrum.
A measurement of the rate of elevation change at a location is: A. viewshed B. slope aspect C. slope D. perspective
C. slope
Code Division of Access
CDMA is a form of spread spectrum. GPS satellite signals, although they are on the same frequency, are modulated by a unique pseudorandom digital sequence, or code. Each satellite uses a different pseudorandom code. Pseudorandom means that the signal only appears random; in fact, it actually repeats after a period of time. Receivers know the pseudorandom code for each satellite. This allows receivers to correlate (synchronize) with the CDMA signal for a particular satellite. q
Manual Rectification
Calculate new output pixel locations (x,y)--relate image location to map location using a "mapping polynomial" function.
Pseudorange
Calculated distance between a GPS satellite and a GPS receiver
network analysis
Calculates the shortest route from a source to a destination through a network and is restricted to follow a linear network
Standard False Color Composite (FCC)
Can be seen if: -NIR wavelengths are displayed through the red filter -Red wavelengths displayed through the green filter -Green wavelengths displayed through blue filter
What can't be done with RS?
Can't see everything (spectral limitations) / Can't see everything at all times (temporal limitations) / Can't see everything everywhere (Spatial limitations) / Can't see everything at any resolution (Spatial limitations)
CSRS
Canadian Spatial Reference System
Multispectral Images
Captures image at specific frequencies across the electromagnetic spectrum -contains a few to several image layers (less than 30) -multispectral sensor can measure multiple wavelength bands simultaneously
The art and science of making maps describes
Cartography
Map making
Cartography is the science of
The pre-made 3D objects in Google SketchUp are called
Components
Land Satellite images allow us to bring in more...
Components of the EM spectrum to see more things (Species differentiation, broad vegetation patterns etc.)
network dataset
Composed of lines, points, and turn features
Orthorectification...
Correcting for elevation differences on the Earth (DOQQ photos)
Cover aerial photography uses...
Cover type mapping into many classes (Different tree species)
Interpolation
Creating s continuous surface from a set of points
The vertical accuracy of a lidar model of terrain is about: A. 30-45 meters B. 15-20 meters C. 1-3 meters D. 15-30 centimeters
D. 15-30 centimeters
A commonly used vertical datum for US geospatial data: A. NED98 B. NAD27 C. NAD83 D. NAVD88
D. NAVD88
A determination of the direction of the steepest slope for an area is: A. Perspective B. Viewshed C. Slope D. Slope Aspect
D. Slope Aspect
methods of determining flow direction
D8-method: simple, define flow among adjacent cells, Prone to error due to overestimation of flow in rigidly-defined orientations D-infinity method: distribute flow to one downslope cell when flow is directly towards the center of that cell; otherwise assigns proportions of flow; More complex equations
The use of a base station or other Earth-bound source to transmit a correction signal to a GPS receiver refers to
DGPS
Inaccuracy of Position Measurement
DOP x Inaccuracy of Range Measurement
EPA hydrologic data source
Data on waters and watersheds that may correspond to HUC's Modern data (RF3) provide a nationally-consistent hydrographic database recording geography and unique identifiers for all surface water features
DGNSS
Differential GNSS
Binary Signals
Digital signals in which on of two values is encoded by modulating a wave characteristic navigation message is produced in this form (+1 and -1 sequence) in pseudorandom noise form
Geometric Correction
Digitally manipulating image data such that the image's projection precisely matches a specific projection surface or shape.
The shortest path between an origin and other nodes on a network can be determined with
Dijkstra's Algorithm
The shortest path between an origin and a destination
Dijkstra's algorithm is used to calculate
Nadir Line
Directly under flight lines, The "trace line" of the ground directly beneath the aircraft while taking photographs
When modeling the world in GIS, when all features are treated as objects with definite locations and boundaries, what is being described?
Discrete object view of the world
Wavelength
Distance from one wave crest to the next.
Quantum Theory
Energy of Quantum = Planck Constant x Frequency
Near infrared energy
Energy rate of 0.7 to 1.3 micrometers
Active Sensor...
Energy source such as an instrument within the RS Electromagnetic Spectrum
Passive Sensor...
Energy source such as the sun within the RS Electromagentic Spectrum
When the correct satellite position is not being sent, what type of error is being encountered?
Ephemeris
In the video lectures we defined seven key TIGER attributes. Associate the attribute name with its characteristics
FID: Field ID Number LENGTH: Length of full extent FNODE: Intersection of "start" of street TNODE: Intersection of "end" of street FENAME: Street name FRADDR: # of first house on right side TOADDL: # of last house on left side
(T/F) The average person can receive information from L1 frequencies when he or she is indoors.
False
(T/F) The goal of SA was to make C/A (coarse acquisition) code on the L1 frequency more accurate
False
(T/F) Users of GPS (on the ground) can send information back to satellites orbiting the earth.
False
A horizontal datum is a baseline used as a starting point in measuring elevation values (either above or below this value)
False
GeoTIFF files do not carry spatial referencing
False
If only one height value can be assigned to a coordinate, then the data is considered fully 3D
False
In general, a narrower contour interval is used when mapping more mountainous terrain.
False
KMZ files cannot be used in Google Earth
False
The geoid and mean sea level are essentially the same
False
As frequency increases, speed of light increases:
False.
Application
GNSS user equipment provides the computed position and time to the end user application, for example, navigation, surveying or mapping.
Reception
GNSS user equipment receives the signals from multiple GNSS satellites then, for each satellite, recovers the information that was transmitted and determines the time of propagation, the time it takes the signals to travel from the satellite to the receiver.
GOES Imager: Spectral Resolution
GOES 8-10 have 5 band spectral resolution
GOES Imager: Temporal Resolution
GOES Imager has a repeat time of ~15 minutes
GOES Imager: Spatial Resolution
GOES Imager has an 8km spatial resolution
Three primary geospatial technologies
GPS GIS Remote Sensing
L-Band
GPS operates in a frequency band referred to as the ______, a portion of the radio spectrum between 1 and 2 GHz
GPS (United States)
GPS was the first GNSS system. GPS was launched in the late 1970s by the United States Department of Defense. It uses a constellation of 27 satellites, and provides global coverage.
The three primary geospatial technologies are
GPS, GIS, and remote sensing
The European Union's version of GNSS is known as
Galileo
Galileo (European Union)
Galileo is a civil GNSS system operated by the European Global Navigation Satellite Systems Agency (GSA). Galileo will use 27 satellites with the first Full Operational Capability (FOC) satellites being launched in 2014. The full constellation is planned to be deployed by 2020.
Who took the first aerial photograph?
Gaspar Felix Tournachon
Remote Sensing (RS)...
Gathering data and information about the physcial world by measuring electromagnetic radiation (Associated with objects located beyond the immediate vicinity of the sensor device[s]) / Measuring an object from a distance / In GIS: Using photographic or satellite images to gather spatial data
GPS satellites are
Geo-stationary
The process of hiding small objects in an area, then listing their coordinates on the Web in a form of "treasure hunting" is known as:
Geocaching
Ways to Download Remote Sensing Data
Geoeye GloVis (USGS) Earth Explorer (USGS) MODIS website Global Land Cover Facility EROS/USGS Seamless Explorer
Geoeye: Sensor
Geoeye has .4m Pan, 1.6 MS sensor
Geoeye: Spatial Resolution
Geoeye has 0.4, Pan, 1.6 MSS spatial resolution
Geoeye: Spectral Resolution
Geoeye has 5 bands (pan, blue, green, red, IR)
Geoeye: Temporal Resolution
Geoeye has a repeat time of 3 days
Geoeye
Geoeye-1 was launched by Geoeye in 2008.
Which of the following is not a common datum?
Geographic Coordinate System (GCS)
Acquiring real-time location information from a series of satellites in orbit best describes
Global Positioning system
9. KML and KMZ files are the native file format used to work with 3D objects in:
Google Earth
KMZ files are the native file format used to work with 3D objects in
Google Earth
The control segment of GPS is composed of a series of
Ground Stations
Geocaching
High tech "treasure hunting" that is assisted with GPS
Which method of making a terrain model look more realistic involves showing how the terrain would look under different lighting conditions?
Hillshade
HDOP
Horizontal Dilution of Precision
IKONOS: Sensor
IKONOS has 1m Panchromatic, 4m Multispectral sensor
IKONOS: Spatial Resolution
IKONOS has 1m pan and 4m MS spatial resolution
IKONOS: Spectral Resolution
IKONOS has 5 bands (pan, blue, green, red, near IR)
IKONOS: Temporal Resolution
IKONOS has a repeat time of 3-5 days off-nadir
Relief Displacement
INCREASES more as you move away from the centre of the air photo (radial distance = r). INCREASES as the flying height (H) DECREASES. This effect can be used to measure the height of an object (h).
terrain or morphometric features
Identifiable surface features: Peaks, Saddles, Planes, Cliffs, Channels, Passes, Ridges, Pits
Color IR aerial photography uses...
Improved differentiation of tree species / Forest Health (Disease / Insects)
Challenges to VDOP
In Canada, and in other countries at high latitude, GNSS satellites are lower in the sky and achieving optimal DOP for some applications, particularly where good VDOP is required, is sometimes a challenge.
Polygons
In a vector data model of a fairly small geographic area, such as N.C., counties and their boundaries would likely be represented as
A network of computers and computer networks, copper wires, fiber-optic cables, wireless networks combine to make the:
Internet
The incoming radiance to the earth, the amount of energy that hits a certain amount of the earth's surface.
Irradiance
What is an 'orthophoto'?
Is a photo that has been geometrically corrected through rectification so that the scale of the photo is uniform and planimetrically corrected to remove distortion caused by camera optics, camera tilt, and differences in elevation. Makes it look like you are looking straight down at every point
Landsat 4,5: Temporal Resolution
Landsat 4,5 have a repeat time of 16 days
Landsat 4,5
Landsat 4,5 were launched in 1982 and 1984 TM
An example of a satellite using a near-polar orbit is:
Landsat 7
MODIS: Temporal Resolution
MODIS has an individual satellite repeat time of 2 days. The different satellites combine create 1 day repeat time.
Most remote sensing systems can collect data in both a panchromatic and a multispectral mode. What is one advantage of each mode?
MSS mode shows colour bands, pan mode is black and white. good for showing roads and features.
Which of the following allows businesses to gather valuable info about you that they can then sell to other companies
Magazine subscriptions, web browser cookies, warranty cards, loyalty card programs
2
Maps often use _____ different fonts to avoid making the map too difficult to read
Better spectral resolution=
More detail for the same interval -more bands
Landsat satellites sense _________
More than one band (each band corresponds to a wavelength range)
Temporal resolution
More than one image over time -the revisit time between satellite passes -finer temporal resolution= shorter revisit time
Terra flies as part of the
Morning Constellation.
NASA
National Aeronautics and Space Administration. Responsible for aviation and spaceflight.
What type of orbit does a remote sensing satellite have to be in to acquire images of sea ice? Why?
Near polar orbit, so it passes close to the poles and can pick up sea ice.
Tobler's first law of Geography states "Everything is related to everything else, but ______ things are more related than ______ things."
Near, distant (Spatial dependence)
Tabular Data
Non-spatial data -can be done in any database management system (Microsoft access, Oracle, SQL, EXCEL) -does not specifically require a GIS
Attributes
Non-spatial data in GIS
NDVI
Normalized Difference Vegetation Index - determine areas with / without lush vegetation
GPS, VLBI, SLR, DORIS
Nowadays, four main geodetic techniques are used to compute accurate coordinates
Frequency
Number of crests passing a fixed point in a given period of time.
the multispectral instrument on board landsat 8 is
OLI
Low-oblique
Oblique image not showing herizon
NAD83 vs NAD27
One of the primary difference is that NAD83 uses an Earth-centered reference, rather than a fixed station in NAD27. All coordinates were referenced to Kansas Meade's Ranch (39°13'26.686″ north latitude, 98°32'30.506″ west longitude) for NAD27 datum. The National Geodetic Survey relied heavily on the use of Doppler satellite to locate the Earth's center of mass.
gps error compensation
One way of compensating for clock error is to download precise satellite clock information from an Spaced Based Augmentation System (SBAS) or Precise Point Positioning (PPP) service provider.
Digital Ortho Quarter Quad (DOQQ)...
Orthorectified images
Clip
Outcome is a specific part of the data sheet that you want to show on its own
A military receiver is required to pick up which of the following? C/A code Almanac L1 frequency P Code
P Code
10.23 MHz
P-Code frequency
Precise Code
P-code is abbreviation for?
decimeter
PPP accuracy
Types of aerial photographs...
Panchromatic (Black & White) / True Color / Color Infrared (CIR)
Which of the following is an example of non-spatial data?
Parcel database of all residential developments in a neighborhood
arrangement of objects
Pattern
Viewing a digital terrain model from an oblique angle to make it appear three dimensional is called..
Perspective View
Geographic Coordinates
Phi, Lambda, Z - defining lat, long using an ellipse rotated about an axis - elevation, z, determined using a geoid, a surface os constant gravitational potential - earth datums define standard values of the ellipsoid and geoid
False-Color or Color Infrared Photo...
Photographs where the green, red, and NIR portions of the spectrum are captured separately / Features that reflect green are displayed blue, features that reflect red are displayed green and features that reflect NIR are displayed red / Useful for highlighting vegetation
Natural (True) Color Photos...
Photos where light from the blue and green protions of the spectrum are captured separately / Features that reflect blue light are blue, green light are green, and red light are red...
Which of the following is NOT one of the three main/cooperating segments of GNSS? Control Segment Position Segment User Segment Space Segment
Position Segment
GNSS Augmentation
Positioning based on standalone GNSS service is accurate to within a few metres. The accuracy of standalone GNSS, and the number of available satellites, may not be adequate for the needs of some users.
A 3D style choropleth map is a
Prism map
Extrusions on a map are called _____
Prisms
Transmission time (t) multiplied by the speed of light (c) gives you the
Pseudorange between receiver and satellite
QZSS (Japan)
QZSS is a regional navigation satellite system that provides service to Japan and the Asia-Oceania region. The QZSS system is planned to be deployed by 2018.
Vegetation Indices
Quantitative measures, based on digital values, that attempt to reduce the multiple bands of data down to a single number per pixel that is related to vegetation characteristics such as biomass, aboveground net primary productivity, leaf area index, and/or percent vegetative ground cover
QuickBird: Spatial Resolution
QuickBird has 0.6m Pan, 2.4m MS spatial resolution
QuickBird: Sensor
QuickBird has 0.6m Panchromatic, 2.4 MS sensor
QuickBird: Spectral Resolution
QuickBird has 5 bands (pan, blue, green, red, IR)
QuickBird: Temporal Resolution
QuickBird has a repeat time of 5 days
QuickBird
QuickBird was launched by EarthWatch in 2001.
Microwave bands
Radar imaging technique --radar dish that pulses microwaves that bounce off any object in its path --EX: LiDAR, NED data
Normal Color Film
Records 0.4-0.7 microns (Blue, Green, Red) Depicts terrain in same hues as we see it.
Land Cover
Refers to the TYPE of feature present Eg: Lake, cornfield, maple trees
Land Capability
Refers to the ability of land to support a certain land use Eg: the ability of the land to support crops
Spatial info
Refers to the information being handled by GIS
Environmental conditions for the planet Earth can be monitored by which of the following?
Remote Sensing
Environmental conditions on earth can be monitored by:
Remote sensing (taking images constantly)
Precision
Repeatability of a measurement
Image
Representation of an object. Includes photographs, but not limited (remote sensors do not take photographs)
Image Pixel
Represents the brightness of each area with an integer value or digital number.
Automatic Rectification
Resampling--fill in the geometrically correct cells with DN values, nearest neighbor, Bilinear interpolation, and cubic convolution.
Temporal Resolution..
Resolution Type that is a repeat cycle of the sensor (Amount of time it takes the sensor to re-capture information about the same area)
Spectral Resolution...
Resolution type where the portion or portions of the electromagnetic spectrum are recorded by the sensor
slope
Rise relative to horizontal distance Typically reported in degrees relative to horizontal Calculated using the tangent function May also be reported as a percentage or fraction Changes over the area of the data Not necessarily aligned with raster grid
Slope is calculated as
Rise/Run
TIGER / Line files
Road network data is provided by the U.S. Census Bureau in the form of
space based augmentation system
SBAS
Which is NOT true about SKP files? -They are native to Google SketchUp -Only one SKP file can be open at a time -SKP files allow you to see how mulitple buildings look next to one another -Google SketchUp must be running for an SKP file to be viewed
SKP files allow you to see how multiple buildings look next to one another
SPOT
SPOT-7 is the most recent of the french satellites. Not yet in orbit
SPOT: Spectral Resolution
SPOT-7 will have 5 bands (Pan, Blue, Green, Red, near IR)
SPOT: Spatial Resolution
SPOT-7 will have a 1.5m Pan and 'Color Merge' resolution and 8m MS
What is the SCL?
Scane Line Corrector on Landsat 7 ETM.
A DRG is a
Scanned version of a USGS topo map
Photogrammetry
Science of making measurements from photographs, especially for recovering the exact positions of surface points.
shadings caused by a light source
Shadow
the form of an object
Shape
Ways to interpret an aerial photo
Shape - particular form of an object in an image. An oval shape can be used to identify a racetrack. Size - the length, width, and area on the ground of objects in the image Shadow - the dark shape cast by an object with a source of light shining on it. Can help provide info about height and depth of objects Tone - the particular grayscale or intensity of a particular color of objects in an image. Light blue color helps distinguish a swimming pool. Texture - differences of certain shading or color throughout parts of the image. Can be coarse or smooth. Pattern - the physical arrangement of objects in an image. How objects are ordered or disordered can help interpret the image. Site - location of characteristics of an item Association - relates an object in an image to other nearby features in the image
Aerial photography interpretation relies on analysis of...
Shape / Association / Pattern / Location / Tone / Texture / Shadow
Pixel
Short for picture element. A pixel is the smallest logical unit of visual information that can be used to build an image.
X-ray
Shorter wavelength than visible light SO there is more energy per unit --> DANGEROUS
Small scale maps
Show a LARGER geographic area than large scale maps
SRTM
Shuttle Radar Topography Mission --mission that collected most of the data we have today for NED data --measured 80% of earth --contained two types of antenna panels; C-band(DEM) and X-band (NED)
Multipath error
Signal is bouncing off of something and arrives later than expected
Why do some systems have higher temporal resolutions?
Some bands need more time to get a clear photo ex. Band 6 on Landsat and so takes longer to get around the Earth. Quickbird has a high temporal resolution, but it doesn't have complete coverage of an area. (off-nater)
multipath propagation
Some of the signal energy transmitted by the satellite is reflected on the way to the receiver. This phenomenon is referred to as ______________
Absorbed (RS Electromagnetic Spectrum)...
Some to all of the energy is neither transmitted nor absorbed; the object retains the radiation and is heated by it within the RS Electromagentic Spectrum (Pavement)
Transmitted (RS Electromagnetic Spectrum)...
Some to all of the energy passes through the object within the RS Electromagnetic Spectrum (Clear water)
SBAS
Space based augmentation system
Types of resolutions...
Spectral / Spatial / Temporal
Every surface has a spectrum pattern known as a...
Spectral Signature
Hyperspectural imaging
Spectral imaging technique- collect and processes information from across EMS (imaging for each pixel) Good for continuous sampling of broad intervals of spectrum
A charted identifier for an feature based on its reflectance of different wavelengths of energy is a
Spectral signature
Basic wave law
Speed of Light = wavelength x frequency
Intersect
Tabular data is merged (data sheets are combined)
Oblique Airphoto
Taken from a side angle. High oblique and Low oblique
Vertical Airphoto
Taken straight down. Usually used in photogrammetry.
Aerial photography
Taking photographs of objects on the ground from an airborne platform
How do you measure heights using Relief Displacement?
Tall buildings will have its roof's position on the photo displaces radially outward from nadir (away from the centre of the photo). The distance measured on the air photo, from the bottom to the top of one side of the building is the objects reflief displacement.
Flagship satellite for the EOS programis
Terra
Nadir line
The "trace line" of the ground directly beneath the aircraft during acquistion.
MODIS: Spectral Resolution
The MODIS sensor has a 36 band spectral resolution
NASA
The National Aeronautics and Space Administration, established in 1958; it is the U.S. government's space exploration and aerospace development branch.
TES
The Tropospheric EMission Spectrometer instrument onboard Aura.
All of the following help to explain why GPS isn't perfectly accurate, EXCEPT: -A poor geometric arrangement of satellites. -The U.S. Department of Defense currently uses Selective Availability in the interest of national defense. -The multipath effect. -Atmospheric interference in the ionosphere and troposphere.
The U.S. Department of Defense currently uses Selective Availability in the interest of national defense.
The original developer of NAVSTAR GPS was which country's Department of Defense?
The United States
Phase Center Stability
The _____ _______ of the antenna is the point where the signals transmitted from satellites are collected. When a receiver reports a location fix, that location is essentially the _______ _________ of the antenna.
What is 'relief displacement' in an aerial photo?
The apparent leaning out of the top of a higher object on a vertical air photo If the top of a feature is higher than the elevation of the nadir point, then it will be displaced outward and imaged at a slightly lower scale.
FRADDL
The beginning address number on the left side of a street segment in geocode
FRADDR
The beginning address number on the right side of a street segment in geocode
Query
The conditions used to retrieve data from the database
Digitizing
The creation of vector objects through sketching or tracing representations from a map or image source is called
Phenology...
The cyclical pattern of growth and senescence
Remote Sensing (in geospatial technology)
The data being acquired is information about the light energy being reflected off of a target (from an aircraft or spacecraft)
Wien's Displacement Law
The dominant wavelength of a blackbody
TOADDR
The ending address number on the right side of a street segment in geocode
Amplitude
The equivalent to the height of each peak, often measured in energy levels or watts.
Principle Point
The exact point on the Earth where the optical axis of the camera was pointing during the instant of exposure. Only point without manipulation.
Phase
The extent to which the peaks of one wave form align with those of another.
Digital Line Graph (DLG)
The features (such as roads, rivers, or boundaries) digitized from USGS maps -vector data applications
dual- frequency operation PPP
The first-order ionospheric delay is proportional to the carrier wave frequency. Therefore, the first-order ionospheric delay can totally be eliminated by using the combinations of dual-frequency GNSS measurements
FENAME
The geocoded name of a street
Spatial resolution is a measure of:
The ground size of one pixel's worth of imagery
The Internet
The hardware part. Big collection of computers and cables, wires, fiber optic cables, and wireless networks
Why Use UTC - Not TAI?
The high level of precision achieved by using atomic clocks is both a blessing and a curse. On the one hand, accurate time-keeping is a necessity, for example for time-sensitive technology, such as modern air traffic control systems that rely on satellite navigation. On the other hand, TAI does not take into account the Earth's slowing rotation, which determines the length of a day. For this reason, TAI is constantly compared to UT1. Before the difference between the two scales reaches 0.9 seconds, a leap second is added to UTC.
Land Use
The human activity or economic function associated with land
Legend
The map element that serves a guide to the various colors and symbols on the map is the
Map Distance (MD)
The measured distance from Point A to Point B in inches on the USGS topo map
Photo Distance (PD)...
The measured distance from Point A to Point B on a photo
Photogrammetry...
The measuring of photographs
Linear interpolation
The method used to plot a point at its approximate distance along a segment is
Raster data model, grid cells
The model used to represent continuous fields in GIS is the ______ which represents data in a set of ______
Spectral Resolution
The number and size of spectral regions the sensor records data, bands and regions.
Spectral Resolution
The number of spectral bands (as in electromagnetic spectrum) in which the sensor can collect reflected radiance.
Dissolve
The original version of a map of the United States shows each state's boundaries, another map is created from the original just showing the outline of the entire US., the state boundaries having been eliminated. What type of operation was performed
troposphere
The other layer of the atmosphere that influences the transmission of GPS signals is the _________, the lowest layer of the Earth's atmosphere. The thickness of the _______ varies, about 17 km in the middle latitudes, up to 20 km nearer the equator, and thinner at the poles. _________ delay is a function of local temperature, pressure and relative humidity. L1 and L2 are equally delayed, so the effect of __________delay cannot be eliminated the way ionospheric delay can be.
Exitance
The outgoing radiance from the earth, back to the atmosphere.
Radiometric Resolution
The sensitivity of dectors to small differences in EMR; basically the ability to note slight differences in energy.
Spatial Resolution
The size of the instantaneous-field-of-view.
Radiometric resolution
The smallest change in the intensity that can be detected by the sensor in the electromagnetic spectrum
The Web
The software part. A collection of web pages connected through hyperlinks and URLs. Service provided by the internet
FETYPE
The street name type such as ST., Rd, and Ln. in geocode
GIS
The term used for a computer based set of hardware and software that captures, analyzes, manipulates, and visualizes spatial information is
Topology
The term used to describe how vector objects connect to one another (in terms of adjacency, connections, containment, and so forth) is
Sidereal Time vs. Solar Time
The time measured by the stars is called sidereal time. It is not the same as solar time, so scientists have to mathematically convert their measurements to arrive at UT. Sidereal time reflects the period it takes Earth to complete a full rotation around its axis in relation to a fixed object outside of Earth's orbit around the Sun. Universal Time, on the other hand, refers to the time it takes Earth to complete a full rotation in relation to the Sun. Since the Earth revolves around the Sun, moving in the same direction as it spins around its axis, it has to rotate a little further each day to catch up with the Sun. This makes a solar day a little longer than a sidereal day—just under 4 minutes on average.
How does project success vary?
The training and experience of the interpreter, the nature of the object being interpreted, the quality of the photos beinf utilized.
GNSS FACTS! user segment
The user segment consists of equipment that processes the received signals from the GNSS satellites and uses them to derive and apply location and time information. The equipment ranges from smartphones and handheld receivers used by hikers, to sophisticated, specialized receivers used for highend survey and mapping applications.
By applying vertical exaggeration to a model which of the following will occur
The vertical scale is made larger than the horizontal scale
ZIPR
The zip code for the right side of a street segment in geocode
What do horizontal measurements rely on?
They primarily rely on knowing the accurate scale for each region of the photo (scale changes with changes in elevation)
External Error Correction Data PPP
This includes satellite orbit and clock corrections. In the case of TerraStar service, the corrections generated are broadcast for end-users by Inmarsat telecommunication satellites.
Stefan-Boltzmann Law
Total emitted radiation from the black body is proportional to the fourth power of its absolute temperature.
____________ occurs when a wavelength of energy simply passes through a surface to interact with something else later.
Transmittance
TIN stands for
Triangulated Irregular Network
GPS works through a process of ______
Trilateration
(T/F) GPS is a "public domain" good in that it is free and available to everyone worldwide.
True
(T/F) GPS satellites have atomic clocks, wheres typical GPS receivers have inexpensive quartz clocks.
True
A base height represents the elevation of the terrain above a vertical datum
True
A digital terrain model (DTM) is a model of the landscape that is used in conjunction with GIS or remotely sensed imagery
True
A topographic map shows the features on the land.
True
Communication systems, electrical power grids, and financial networks all rely on precision timing from GPS for synchronization and operational efficiency.
True
Contour lines on a map represent areas of constant elevation
True
Differential GPS requires at least one other GPS receiver be running at the same time on a known location.
True
Esri's ArcGlobe allows 3D visualization on a global level
True
Ideally 3D models should be georeferenced
True
Ideally, 3D models should be georeferenced
True
In draping, a remotely sensed image is overlaid on a hillshade
True
Income alone is not a key determinant in ESRI's market segmentation groupings
True
Remote sensing is the process of collecting information related to the reflected or emitted electromagnetic energy from a target by a device a considerable distance away from that target from an aircraft or spacecraft.
True
Satellites with a geostationary orbit rotate at the same speed as Earth
True
Slope is often calculated as rise over run and expressed in either degrees or percentages
True
The information that is being sensed is the reflection of electromagnetic (EM) energy off a target
True
Using the notation in ArcGIS aspect values that range between 340-360 and between 0-20 would be considered as north or at least northerly
True
Reflectance is a unitless ratio.
True.
The increasing ubiquity of location based services is leading to loss of privacy
True.
The progenitors of today's submarine fiber optic cables were the submarine telegraph cables linking disparate portions of the British Empire
True.
The web requires the internet to work
True.
Virginia has two state plane and UTM systems
True.
What is the order of the bands?
UV, blue, green, red, NIR, TIR, Micro
The geoid
Undulates, is more or less similar to mean sea level, is a surface of uniform or equal gravity
USGS
United States Geological Survey
UTC
Universal Time Coordinated- leap seconds are added to universal time at specific epochs in order to keep is close to UT1. this is the basis for civil time, used globally
When selecting an area to examine using Esri business analyst you can
Use a simple circle around a chosen point, use network distance in the form of drive times
Vertical measurements
Use many methods depending on weather you are using a singel air photo or a stereo pair. Single photo - use shadow length method. Stereo Pair - use parallax measurement (many different ways)
The SRTM performed which of the following
Used radar waves from space to map the terrain surfaces of the Earth
Landsat satellite
Used to gather data for images of Earth's land surface and coastal regions -equipped with sensors that respond to Earth-reflected sunlight and infrared radiation
Server-side GIS:
Users (clients) submit requests for data and analysis to a web server. The server processes the requests and returns data or a solution to the remote client -Disadvantages: It may be affected by bandwidth and internet traffic, every request must be processed and passed through internet
Client-side web GIS
Users to perform some data manipulation and analysis locally on their own machines -Can be more difficult to implement because they require additional software and user expertise to be effective
Cholera
Using spatial analysis Dr. John Snow traced the source of which disease to London's water pumps
national hydrologic dataset (NHD)
Vector based spatial data about surface waters Combines data from USGS digital line graphs (DLG's) and EPA "river reach" data Based on 1:100,000 scale Shows both natural and manmade features Represent topology network, with lines assigned directionality Can identify both connections and bypasses Organized in a hierarchy of nested, coded hydrologic units Use HUC's
Most reflectance in NIR (near infrared light):
Vegetation
Which regions of the spectrum show the largest reflectances for vegetation/soil/water?
Vegetation: NIR Soil: red Water: Low in all visible spectrums
Have more capabilities than
Vehicle navigation systems typically _____ a GPS reciever
How are air photos taken?
Vertical air photos are taken along flightlines or flight strips.
What are some conditions of vertical air photos?
Vertical air photos have the same map projections as planar or azimuthal map projections. Measurements are reliable from the centre point (PP) outwards only. This is why we use the Cartesian Coordinate System for all measurements.
Big Data can be described by
Volume, Velocity, Variety, Value
Which of the following software packages is the best to use to create the landscapes, trees and vegetation in visualization
Vue
The datum used by GPS is
WGS84
Black and White Infrared
Water shows up black, healthy vegetation bright white (it reflects 40-70% IR light)
Electromagnetic Spectrum
Waves characterized by wavelength location over which electromagnetic radiation extends -usual units are micrometer
small registration marks exposed on the film at the edges of a photo
What are fiducial marks on an air photo?
a film that is sensitive to infrared wavelengths and visible light
What is a CIR air photo?
has film with sensitivity to visible light from 0.3 to 0.7um
What is a panchromatic air photo?
overlaying conventional map symbols on an orthophoto
What is an annotated orthophotomap?
imagery in which distortion from the camera angle and topography has been removed
What is an orthophoto?
1"=400miles
What is not a component of geographical scale
It should leave fairly large areas empty to give the readers' eyes a rest
What is not a principle of effective map layout
The map should make use of as much color as possible
What is not a principle of good map design
Median
What is not a type of data classification commonly used by GIS in creating cloropleth maps
The full length of the road
What is not a valid attribute for the line segments of a long road
duplicated image of the ground in two successive air photos
What is overlap in air photos?
process of obtaining measurements from aerial photos
What is photogrammetry?
the apparent leaning out of the top of a higher object
What is relief displacement in an aerial photo?
data collected by an aircraft in the form of electromagnetic energy being reflected off a target
What is remote sensing?
vertical photographs are taken from a 90 degree angle and can be scaled, whereas oblique photos are taken from an angle and have distorted scale
What is the difference between a vertical aerial photo and an oblique aerial photo?
the center of an aerial photo
What is the principal point of an aerial photo?
Geoprocessing
When a layer has some sort of action performed to it and the result is a new layer
True
When a vehicle navigation system provides incorrect directions to a driver, the error is usually a result of problems in the base network data
Discrete object view of the world
When all features are treated as objects with definite locations and boundaries
Transmission
When light passes through a target
Conjugate Principle Point
When the principle point appears in an adjacent photo.
Houses
Which of the following is not a feature of the digital line graphs (DLSs) created from the USGS
Cardinal Data
Which of the following is not a form of attribute data in GIS
Angles
Which of the following is not used by GIS systems that utilize the discrete object view
1:500,000
Which of the following is the smallest-scale map
Union
Which would result from the following compound query? INC2013>=35000 OR MEANINC2013>28500
"Digital divide"
Who has the internet and who doesn't (societal change)
to correct for UV effects (modified other colors), and to eliminate haze (dust particles)
Why do panchromatic air photos need a UV haze filter?
WAAS
Wide Area Augmentation System
What does WAAS stand for
Wide Area Augmentation System (covers United States and portions of N. America)
Satellite geometry: Error is reduced if satellites are:
Widely spaced
Attribute Error
Wrong quantities or descriptions associated with features, or missing or invalid values
Which of the following is the most highly encrypted and secure? The L1 frequency C/A code P Code Y Code
Y Code
Can we find the true planar location of an object if we don't know its elevation?
YES! using a stereo parallax and a stereo pair of air photos. The 60% overlap means that the principle point from the neighbouring photo can be seen on the first photo (these are called the conjugate principle points). The distance between the PP and the conjugate principle point is the photo base length (distance between exposures)
Reference map
You are visiting Seattle and receive a map from the Seattle Visitors' Bureau showing the streets of downtown Seattle and points of interest. You are looking at a
If you were in Central America and wanted to take some spectral reflectance measurements on the ground at the same time as a Landsat or SPOT satellite passes overhead, at about what time should you start taking your measurements? Why are the satellites programmed to cross overhead at this time?
You should start taking measurements on a sunny day at mid morning. Satellites are programmed to cross overhead at this time because they are sun synchronous, and there are less clouds in mid morning than in the afternoon.
Join
You wish to combine two non-spatial tables using a common field, the operation to do this is called a
5. In 3D design, elevation or height values are referred to with the letter:
Z
In 3D design elevation or height values are referred to with the letter
Z
In the coordinate system, which variable represents elevation?
Z
The value used to represent the height of an object is
Z
Ephemerides
_________________ allow for the satellite position computation which is required in order to triangulate the receiver's position. Thus, it is very common for clients to log the ____________________ of each constellation they are tracking with the receiver.
Virtual Globe
a 3D software model or representation of the Earth or another world
DOQ
a Digital Orthophoto Quad. Orthophotos that cover an area of 3.75 minutes of latitude by 3.75 minutes of longitude. or one-fourth of a 7.5 minute USGS quad.
dual frequency
a GPS receiver that can pick up both the L1 and L2 frequencies
single frequency
a GPS receiver that can pick up only the L1 frequency
user segment
a GPS unit somewhere on the earth that is receiving the signals from the satellite
ambiguity resolution
a complicated process needed to determine the number of whole cycles when using RTK receiver high precision GNSS receivers can resolve the ambiguities almost instantaneously
One key part of all API project reports is....
a description of the image characteristics for each feature of interest. Describe each land cover class and/or describe the shape, shadow, ect for each feature. Recording these characteristics helps to maintain consistency during the API.
8-bit imagery
a digital image that carries a range of brightness values from 0 to 255
TIGER/Line
a file produced by the US Census Bureaeu that contains the line segments that correspond with roads all over the United States
The american fact finder is
a government developed tool for investigating and accessing US Census data
laser interferometer
a gravimeter operates by an object being dropped inside a vacuum chamber, its position is then monitored very accurately using a __________ _________________?
PLEIADES
a high resolution series of satellites.
A small-scale map would show
a larger geographic area than a large-scale map.
In a GIS network an "edge" represents
a link on the network
in a GIS network, an edge represents
a link on the network
Landsat
a long-running United States remote sensing project that had its first satellite launched in 1977 and continues today.
navigation message
a low bit rate message that includes the following information: GPS date and time. Satellite status and health. If the satellite is having problems or its orbit is being adjusted, it will not be usable. When this happens, the satellite will transmit the out-of-service message. Satellite ephemeris data, which allows the receiver to calculate the satellite's position. This information is accurate to many, many decimal places. Receivers can determine exactly where the satellite was when it transmitted its time. Almanac, which contains information and status for all GPS satellites, so receivers know which satellites are available for tracking. On start up, a receiver will recover this "almanac." The almanac consists of coarse orbit and status information for each satellite in the constellation.
cognitive map
a map-like representation in the black-box of our nervous system
NDVI
a method of measuring the health of vegetation using near-infrared and red energy measurements.
linear interpolation
a method used in geocoding to place an address point among a range of addresses along a link
band
a narrow range of wavelengths being measured by a remote sensing device.
PPP
a positioning technique that removes or models GNSS system errors using just one "dual frequency rover" receiver depends on GNSS satellite clock, and orbit corrections generated from a network of global reference stations once corrections are calculated they are delivered to the rover via satellite or by the internet, delivering 5-10cm accuracy
orthorectification
a process used on aerial photos to remove the effects of relief displacement and give the image uniform scale.
Datum
a reference surface of Earth
Gaussian Geoid Definition
a refined model of the figure of the earth. described as the equipotential surface of the earths gravity field, coinciding with the mean sea level of the oceans
EGNOS
a satellite based augmentation system that covers Europe
MSAS
a satellite based augmentation system that covers japan and nearby regions
WorldView-2
a satellite lauched in 2009 by the DigitalGlobe company, featuring in 8-band multispectral sensor with 1.84-meter resolution and a panchromatic sensor of 0.46-meter resolution.
GeoEye-1
a satellite lauchned in 2008 by the GeoEye company, which features a spatial resolution of 41 centimeters with its panchromatic sensor.
IKONOS
a satellite launched in 1999 by SpaceImaging, Inc. (now called GeoEye), which features multispectral spatial resolution of 4 meters and panchromatic resolution of 1 meter.
EO-1
a satellite launched in 2000 and set to orbit 1 minute after landsat 7
QuickBird
a satellite launched in 2001 by the DigitalGlobe company, whose sensors have 2.4 meter multispectral resolution and 0.61-meter panchromatic resolution.
WorldView-1
a satellite launched in 2007 by the Digital Globe company, whose panchromatic sensor has 0.5-meter spatial resolution.
SPOT
a satellite program operated by the French Space Agency and the Spot Image Corporation.
along-track
a scanning method using a linear array to collect data directly on the path the satellite moves on.
across-track
a scanning method using a rotating mirror to collect data by moving the device the width of the satellite's swath.
hyperspectral sensor
a sensor that can measure hundreds of different wavelength bands simultaneously.
Multispectal sensor
a sensor that can measure multiple different wavelength bands simultaneously.
panchromatic sensor
a sensor that can measure one range a wavelengths.
radiometric resolution
a sensor's ability to determine fine differences in a band of energy measurements
temporal resolution
a sensor's capability that determines how often it can view the same location on the ground.
What is EOS
a series of remote sensing satellites operated and maintained by NASA
Afternoon Constellation
a set of satellites that pass the equator in the afternoon during their orbits.
Morning Costellation
a set of satellites that pass the equator in the morning during their orbits.
algorithm
a set of steps used in a process to solve a particular type of problem
landsat scene
a single image obtained by a landsat satellite sensor
road segment
a small portion of a road network that can have multiple attributes
UT (Universal Time)
a time standard that reflects the average speed of the Earth's rotation. not measured by clocks but by looking at the stars - using prime meridian at 0 longitude as a reference point, it shows the actual length of an average solar day on Earth, which is the time from one solar noon to the next -during a solar day, our planet completes a full rotation around its axis in relation to the sun. Because of the Earth's slowing rotation, a solar day is a little longer than 24 hours on average - despite being defined as in relation to the sun, UT is usually measured by the stars. ensuring a higher degree of accuracy
PPP accuracy
a typical solution requires a period of time to converge to decimeter accuracy in order to resolve any local biases such as (atmospheric conditions, multipath environment and satellite geometry) actual accuracy acheived and the convergence time required is dependent on the quality of the correction and how they are applied to the receiver
nanometer
a unit of measurement equal to one-billionth of a meter abbreviated nm.
an atmospheric window is best described as
a wavelength of energy that is most easily transmitted to the earth
Small Scale maps would use
a wider contour interval than a larger scale map
3. Which of the following representative fractions would indicate the largest scale map? a. 1:1 b. 1:0 c. 1:1000000 d. 1:24000
a) 1:1
In order to create a colour composite image, we select 3 bands from a multispectral scene and display one band in red, the second in green, and the third in blue. If you wanted to display a Landsat ETM image, which ETM band numbers would you assign to each colour to create: (a) a true colour composite; and (b) a standard false colour composite?
a) Band 1: blue, band 2: green, band 3: red b) Band 4: red, band 3: green, band 2: blue
25. The shortest path between an origin and other nodes on a network can be determined with a. Dijkstra's Algorithm. b. network junctions. c. address standardization. d. impedance.
a) Dijkstra's Algorithm
16. Which of the following data formats will result in the least loss of data of a map graphic? a. TIFF b. JPEG c. DPI d. CMYK
a) TIFF
2. A small-scale map would show a. a larger geographic area than a large-scale map. b. a smaller geographic area than a large-scale map. c. the same geographic area as a large-scale map, just at a smaller resolution. d. the same geographic area as a large-scale map, just at a larger resolution.
a) a larger geographic area than a large-scale map
22. In a GIS network, an "edge" represents a. a link on the network. b. an intersection on the network. c. the side of the road on a network. d. the boundary of a road on the network.
a) a link on the network
9. A map template provides a. a pre-arranged way of placing elements on a map. b. a blank space that can be used to place items on a map. c. a pre-made map that can immediately be printed. d. previously created symbology already applied to the map's legend.
a) a pre-arranged way of placing elements on a map
5. A very-large-scale map would likely show a. more detail than a very-small-scale map. b. less detail than a very-small-scale map. c. the same amount of detail as a very-small-scale map, just at a smaller resolution. d. the same amount of detail as a very-small-scale map, just at a larger resolution.
a) more detail than a very-small-scale map
15. Having all count values of the data brought to the same level describes a. normalization. b. graduated symbols. c. cholopleth mapping. d. reference mapping
a) normalization
19. TIGER files typically contain all of the following data except a. number of houses per street. b. address ranges on streets. c. zip code information for streets. d. names of streets.
a) number of houses per street
4. On a very small scale map, cities would likely be shown as a. points. b. polygons. c. individual lines. d. grid cells.
a) points
12. Which of the following data classification methods attempts to place an equal number of data values in each class? a. Quantiles b. Standard deviation c. Equal interval d. Natural breaks
a) quantiles
28. The base network data used for geocoding is referred to as a. reference database. b. street view. c. linear match. d. standardization.
a) reference database
Why are the orbits for resource satellites: a) sun synchronous, b) near polar, c) have a mid-morning equator crossing ?
a) same time as the sun b) in order to image the whole earth, not just parts of it c) there are less clouds at this time, and it minimizes differences in the data.
23. Address parsing is done to a. separate the parts of an address. b. make sure that all parts of an address have the same format. c. remove incorrect addresses prior to geocoding. d. align each address with a zip code.
a) separate the parts of an address
Which of the following representative fractions would indicate the largest scale map? a. 1:1 b. 1:0 c. 1:1000000 d. 1:24000
a. 1:1
A small scale map would show: a. A larger geographic area than a large scale map b. A smaller geographic area than a large scale map c. The same geographic area as a large scale map, just at a smaller resolution d. The same geographic area as a large scale map, just at a larger resolution
a. A larger geographic area than a large scale map
Which of the following is an example of a reference map? a. A map showing the lakes in Ohio and the number of fishing days per lake b. A map showing the percentage of the population living in poverty per state c. A map showing the degree of employment in each state in the US d. A map of the population density of each country in the world
a. A map showing the lakes in Ohio and the number of fishing days per lake
The "information" being handled by GIS refers to: a. Spatial information b. Tabular information c. Visual information d. Non-spatial information
a. Spatial information
What type of data is NHD? a. Vector b. Raster c. Non-Spatial d. Interoperable
a. Vector
Which geoprocessing operation will select all areas from the first dataset and all areas from the second dataset, except those areas they have in common? a. symmetrical difference b. identity c. union d. intersect
a. symmetrical difference
Energy that is trapped and held by a surface has been
absorbed
energy that is trapped and held by a surface has been
absorbed
____________ occurs when the energy is trapped and held by a surface rather than passing through or reflecting off it
absorption
tens of km
acceptable baseline distance with RTK
1 meter or so
accuracy of DGNSS
3 cm
accuracy of PPP
TIGER files typically contain what data
address ranges on streets, Zip code information for streets, names of streets
Instantaneous sea surface topography
affected by temporal variations of long term, annual, seasonal, and short-term character, occuring at different scales
What are airphotos used for?
air photos are used to compliment, improve, or reduce field work rater then take its place.
oblique photo
an aerial photo taken at an angle.
orthophoto
an aerial photo with uniform scale.
watershed
an area contributing flow to a single area downstream on a landscape (Basins, Contributing areas, Catchments, Drainages)
Y code
an encrypted version of the P code (an anti spoofing technique)
false color composite
an image arranged by not placing the red band in the red color, the green band in the green color gun, and the blue band in the blue color gun.
standard false color composite
an image arranged by placing the near-infrared band in the red color gun, the red band int he green color gun, and the green band in the blue color gun.
true color composite
an image arranged by placing the red band in the red color gun, the green band in the green color gun, and the blue band in the blue color gun.
color composite
an image formed by placing a band of imagery into each of the three color guns (red, green, and blue) to view a color image rather than a grayscale one.
in a GIS network, a junction represents
an intersection on the network
geostationary orbit
an orbit in which an object rotates around earth at the same speed as earth.
Sun-synchronous orbit
an orbital path set up so that the satellite crosses the same areas at the same local time.
near-polar orbit
an orbital path that carries an object around Earth, passing close to the north and south poles.
true orthophoto
an orthophoto where all objects look as if they're being seen from directly above
4. Viewing an image that is offset in both the color red and the color blue that enables a 3D style effect is an example of:
anaglyph
Ellipsoidal Latitude
angle measured in the meridian plane between the equator and the ellipsoid normal at point P. Reckoned positive north
Vertical Angle
angle measured in the vertical plane between the horizontal plane and the direction to the target point. generally the zenith, is used instead of the vertical angle
Satellite Differential Services
another method for obtaining real- time differential correction data in the field by using geo- stationary satellites this system obtains correction from more that one reference station. reference stations collect the base station GPS data and relay the data to a network control center, which sends the information to a geostationary satellite for verification the verified information is sent to the roving GPS receiver to ensure it obtains GPS positions in real time.
3. Which operation would best allow you to place 3D buildings at their proper height on the terrain? (ex. the terrain is 900 ft above sea level, you want the building to sit on the terrain, not float above or below it?)
applying base heights
Differential GPS
are enhancements to the Global Positioning System (GPS) which provide improved location accuracy, in the range of operations of each system, from the 15-meter nominal GPS accuracy to about 10 cm in case of the best implementations.
radio signals
are used to connect the rover station to the base station in DGPS and RTK... this provides real time location in the field
allometric equations
are used to estimate indirect measurements based on biophysical relationships derived through research
why a fourth satellite?
as the clocks of the satellite and the receiver are not synchronized, this is necessary in order to determine the clock synchronization error. Therefore the original distances derived from the travel time of a signal are called Pseudoranges
The wavelengths that pass through the atmosphere are referred to as __________________.
atmospheric windows
why add leap second?
atomic time too accurate - the velocity of Earth's rotation around its own axis does not match the speed of atomic time - on average its a tiny bit too slow, gradually slowing down - compared to earth's rotation, atomic clocks are too consistent - does not mean days are 27 seconds longer now. the only difference is that the days a leap second was added has 86,401 seconds instead of the usual 86,400 seconds
Mean Sea Level
averaging the ocean surface over time (at least a year), or modelling ocean tides provide _____________ for the corresponding time interval. even after reducing all time dependent parts, a quasi-stationary SST would remain
24. Multiple addresses can be geocoded at once via a. address standardization. b. batch geocoding. c. Dijkstra's Algorithm. d. standard geocoding.
b) batch geocoding
13. Which of the following data classification methods selects class break levels by taking the complete range of values and dividing by the desired number of classes? a. Natural breaks b. Equal interval c. Standard deviation d. Quantiles
b) equal interval
18. A major road (such as Virginia Beach Blvd) would be represented in a GIS as a. a single record. b. multiple records, with each representing one piece of the road. c. two records, each representing half of the road's distance. d. one file entitled "FENAME = 'Virginia Beach Blvd'."
b) multiple records, with each representing one piece of the road
11. Which of the following data classification methods selects class break levels by searching for spaces in the data values? a. Standard deviation b. Natural breaks c. Equal interval d. Quantiles
b) natural breaks
21. Linear interpolation is used in geocoding to a. find the exact point where an address is matched to. b. place a point an approximate distance along a line. c. count the number of houses on the street. d. separate the component parts of an address.
b) place a point an approximate distance along a line
26. In a TIGER file, the FEDIRP field refers to a. the name of the street. b. the direction of the prefix of a street. c. the direction of the suffix of a street. d. the type of road.
b) the direction of the prefix of a street
20. The number of units to travel along a link of a network is a. link speed. b. transit cost. c. travel vector. d. via points.
b) transit cost
An area of spatial proximity around a point refers to which GIS operation? a. Spatial Join b. Buffer c. Closed Circle d. Union
b. Buffer
The use of a base station or other earth-bound source to transmit a correction signal to a GPS receiver refers to: a. CORS b. DGPS c. WAAS d. MSAS
b. DGPS
Which of the following boolean operators would be used to determine which parcels of land in a database have an assessed value of more than $100,000 and also are zoned as "residential" areas? a. union b. intersection c. negation d. exclusive or
b. intersection
Which geoprocessing operation will select all areas from the first dataset and also all areas from the second dataset? a. intersect b. union c. symmetrical difference d. identity
b. union
What type of data is NLCD? a. Vector b. Raster c. Non-Spatial d. Interoperable
ba. Raster
A narrow range of wavelengths describes a
band
a narrow range of wavelengths describes a
band
pour point or outlet
base of drainage network
profile plot
based on elevation data along a defined transect line or "profile path" (topographic profile), vertical exaggeration otherwise features would appear flat
dynamical time
based on the motions of bodies in the solar system. is used in celestial mechanics with Newton's equations of motion- eg, as an argument for the astronomical ephemeris of the moon and the sun
Multiple addresses can be geocoded at once via
batch geocoding
multiple addresses can be geocoded at once via
batch geocoding
Pseudorange
biased ranges between the receivers antenna and the antennas of each satellite being tracked
panchromatic imagery
black and white imagery formed by viewing the entire visible portion of the electromagnetic spectrum
6. Extruding a polygon will turn it into a
block
Extruding a polygon will turn it into a
block
similarities of RTK and PPP
both make use of - pseudorange (code based) position estimates - Mitigation of positioning errors, either by using relative positioning or correction data - Multiple satellite signal observations to find the ambiguity terms that fit best with the measurement data
An area of spatial proximity around a point refers to which GIS operation?
buffer
"error" in setting up the theodolite
by orientating it along the plumb line direction instead of the ellipsoidal norma
TAI realized
by a large set (more than 200) atomic clocks (mostly cesium beam frequency standards providing long- term stability and a few hydrogen masers)
10. Which of the following is an example of a thematic map? a. A trail map of a local municipal park b. A map of a new subdivision, showing the locations of new roads and houses c. A map of a neighborhood showing which houses are rentals and which are not d. A map showing the locations of all casinos in Pennsylvania
c) A map of a neighborhood showing which houses are rentals and which are not
7. A key to what the various symbols on a map are representing can be found in the map's a. type. b. labels. c. legend. d. scale bar.
c) legend
Polygons are: a. 0-dimensional objects b. 1-dimensional objects c. 2-dimensional objects d. 3-dimensional objects
c. 2-dimensional objects
Use of WAAS can reduce position error to within: a. 30 meters b. 15 meters c. 3 meters d. 1 meter
c. 30 meters
Which of the following boolean operators would be used to determine which parcels of land in a database have an assessed value of more than $100,000 and are also zoned as "residential" areas, but not parcels that meet both of these criteria? a. Negation b. Intersection c. Exclusive or d. Union
c. Exclusive or
The overall term for the technologies that use signals from satellites to find locations on Earth's surface is: a. NAVSTAR 3D b. Globalnav c. GNSS d. GPS
c. GNSS
Which of the following queries will select all counties that have a population with more than 100000 persons (from a layer called POP) as well as all counties that have more than 100000 housing units (from a layers called HOUSES)? a. POP > 100000 AND HOUSES > 100000 b. (POP AND HOUSES) > 100000 c. POP > 100000 OR HOUSES > 100000 d. POP > 100000 XOR HOUSES =< 100000
c. POP > 100000 OR HOUSES > 100000
Selecting objects from one layer based on their spatial relationship with another layer describes a: a. spatial join b. spatial selection c. spatial query d. spatial attribute
c. spatial query
RTK range calculation
calculated by determining the number of carrier cycles between the satellite and the rover station, then multiplying this number by the carrier wavelength
DOP
can be calculated without determining the range. All that is needed is the satellite positions and the approximate receiver location.
Antenna Gain
can be defined as the relative measure of an antenna's ability to direct or concentrate radio frequency energy in a particular direction or pattern. A minimum ________ is required to achieve a minimum carrier- to-power-noise ratio (C/No) to track GNSS satellites.
ionosphere delay
can be eliminated using dual frequency observations
Ionospheric Corrections
can be made by measuring the difference in transmission delay between the two carrier L1/L2 frequencies for this reason, when a single GPS receiver is used in navigation application, P-Code outperforms C/A code by a large margin
Terrestrial Reference Frame
can be used to measure plate tectonics, regional subsidence or loading and/ or used to represent the earth when measuring its rotation in space
shadows
can be utilized two ways: 1) the shape or outline of the shadow can provide an impression of the profile view of the object. 2) measuring the heights of objects
Air photo mosaics
can cut out and paste cnetral portions of an air photo series together. Central areas have the least distortion (azimuthal map projections)
tropospheric delay
caused mostly by humidity, temperature and atmospheric pressure changes in the atmosphere
1-2 cm a year
change in coordinates when referring to changes over time between ITRF epochs continental drift would likely be the culprit
RTK
code based positioning
Navigation System
code that contains almanac and ephemeris data
viewshed
collective areas that are visible from a given point (areas not blocked by surrounding terrain), calculated based on cell to cell inter-visibility Line of sight drawn between the view cell and target cell Elevation of line is calculated for every intervening cell If the slope to a target cell is less than the slope of a cell closer to the viewpoint along the line of sight, then the target cell is not visible
CIR stands for
color infrared
what type of photo is: near-infrared energy displayed as the color red, red energy displayed as the color green, and green energy displayed as the color blue?
color infrared photo
CIR photo
color infrared- a photo where infrared reflection is shown in shades of red, red reflection is shown in shades of green and green reflection is shown in shades of blue.
Identify the basic elements of object interpretation and give an example of how they can be used when interpreting a remote sensing image.
colour, shape, size, pattern, texture, shadow, and site or association.
FG5
common gravimeter
contour lines
connected lines representing uniform elevation running perpendicular to slope, if not for elevation data, referred to as isopleths Define a regular contour interval Changes in slope steepness easily inferred from closeness of contour lines Closer together = steeper slope Farther apart = shallower slope
Navigation Message
contains the coordinates of the satellites as a function of time- ie ephemeris (Keplerian elements/ orbital corrections) contains a clock correction with respect to GPS- time, the coefficient of an ionospheric refraction model, and information on the status of the GPS system. The broadcast ephemeris are accurate to a few m and approach sub- meter accuracy
Code Based technique
correlates and uses Pseudorandom PRN codes transmitted by four or more satellites to determine position and time
27. Destinations to visit on a network are referred to as a. junctions. b. edges. c. batches. d. stops.
d) stops
A map showing streams in Ohio, displaying the number of available fishing days for each stream is showing line data of which type? a. nominal b. ordinal c. interval d. ratio
d. ratio
almanac
data concerning the status of a GPS satellite, which is included in the information being transmitted by the satellite
ephemeris
data referring to the GPS satellite's position in orbit
Indirect measurements
dbh (diametre at breast height), site index (productivity), growth, stand age, stand structure (volume - individual tree and stand m3/ha, basal area m2/ha)
flow accumulation area
defined by flow direction surface, returns value equal to lateral area being drained through the cell, calculation of area based on defining local topographic high points, sum area beneath high points flowing towards cell of interest
Ephemeris Time
defined by the motion of the earth about the sun and determined through long- term astronomic observations
Element Gain
defines how efficient the antenna element is at receiving the signals. In any signal chain, you are only as good as the weakest link. so an antenna with lower _________ might be compensated by an increased low noise amplifier gain.
PPP solution
depends of GNSS satellite clock and orbit corrections, generated from a network of global reference stations - once corrections are calculated, they are delivered to the end user via satellite or over internet - these corrections are used by the receiver, resulting in decimeter level or better positioning with no base station required
Metadata
descriptive info about the data (data about data)
Site suitability analysis is used to
determine which areas are useful or not useful in spatial analysis
DGPS
differential GPS- a method using a ground based correction in addition to the satellite signals in position determination
the shortest path between an origin and other nodes on a network can be determined with
dijkstra's algorithm
aspect
direction of steepest slope, determines direction of water flow , amount of sunlight received, landscape visibility define with compass (azimuth) direction
flow direction
direction that water would take in the real world - steepest slope (defined based on aspect) - Must remain aware of errors due to subsurface groundwater flow, soil permeability may be saved as a raster of compass angles (aspects), May also show as identifiers of which adjacent cell water will flow to Be aware: Not always simple flow Flat areas and peaks/ridges may be sites of divergent flow Some valley sites may also show convergence from multiple cells
size
directly related to the scale of the photo. The scale of the air photo is critical in identification of the given object. Ex. a buildings purpose can be categorized much easier if its true size is known
deflection of the vertical
does not depend on the azimuth and corresponds to a twist in the observed directions; horizontal angles are not affected
RTK position determination
done using algorithms that incorporate ambiguity resolution and differential correction
Atomic Clocks
each satellite has 2 rubidium and 2 cesium
ITRS
earth fixed, meaning it rotates and moves with the earth origin is center of mass of the earth Z- axis is along the spin axis of the earth X-axis is in line with the vernal equinox (mean) Y-axis is orthogonal to the Z and X axes
color gun
equipment used to display a color pixel on a screen through the use of the colors red, green and blue.
6263856.0
equipotential surface of CGVD2013 numerical value (m^2s^-2)
describe how extrusion relates to true 3D representation of geospatial data
extrusion to a specific z value, 3D is a specific xy value
trilateration
finding a location in relation to three other points of reference
Define spectral signature
fingerprint. an objects unique spectral reflectance curve.
satellites in near polar orbit
follow a north-to-south orbital path
Ephemerides
for GNSS these contain information on week number, satellite accuracies and health, age of data, satellite clock correction coefficients and orbital parameters
RTK accuracy
for applications that require high, such as centimeter accuracy, level positioning up to 1 cm + ppm accuracy
P(Y) code
for military use. It provides better interference rejection than the C/A code, which makes military GPS more robust than civilian GPS.
When does Relief Displacement work the best?
for parts of the scene away from nadir (PP) and for objects that are nearly vertical (buildings, smokstacks). Also when nadir = PP (only reliable when using vertical air photos)
methods for calculating slope
four nearest cells third order finite difference
GNSS Signals
frequencies are around 1.5_GHz (gigahertz)—1.5_billion cycles per second. ____ operates at frequencies that are higher than FM radio, but lower than a microwave oven. By the time _____ signals reach the ground, they are very, very weak
pan sharpening is used to
fuse panchromatic imagery with multispectral imagery to get a finer image
a receiver can only
gather data from the satellite, it cannot transmit data back up to the satellites
High-tech "treasure hunting" that is assisted with GPS is referred to as
geocaching
gps
global positioning system, a technology that uses signals broadcasted from satellites for navigation and position determination on the earth
Regression analysis
ground plot measurements regressed against photo measurements produces allometric equations (ie stand volume = f (tree height, stocking)
17. TIGER files are created and maintained by e. USGS. f. NAVTEQ. g. U.S. Department of Transportation. h. U.S. Census Bureau
h) U.S. Census Bureau
Phase modulation
happens to the carrier wave using the PRN code. used to differentiate satellite signals and to provide signal timing information for range measurements.
Colour film
has 3 active layers. Haze filter reduces blue light (atmospheric scattering). Green active layer also sensitive to blue (green and red light) - use a yellow filter to remove remaining blue light.
Colour Infrared
has 3 active layers. Uses yellow coloured filter to remove blue light. When the CIR neagtive it made into a print; the IR layer is converted to red, the red layer is converted to green, and the green layer is converted to blue. Objects that reflect a lot of IR light show up as RED. Healthy vegetation reflects a lot of IR light (broadleaf plants) - able to see plant stress weeks before in IR then with visible light.
Black and white film
has one active layer that is sensitive to all visible wavelengths. Some films are sensitive to the UV part of the spectrum but the glass lens filters most UV light.
physical maps
help humans build cognitive maps
shaded relief map
hillshade map: depicts brightness of terrain reflections based on a defined location of the sun, brightness depends on local incidence angle between the incoming light and the normal to the surface slope Requires a calculation of visibility - like a viewshed from an elevated position
20,200km
how high are GPS satellites approximately
12
how many hours for a period of revolution- GPS SATELLITES?
6
how many nearly circular orbits in the GPS system?
21 plus 3 spares
how many satellites in the GPS space segment?
Topology (in GIS terms) describes
how objects are connected to one another independently of their coordinates.
On what assumptions do we classify remotely sensed data?
human assumptions based on colour, shape, size, pattern, texture, shadow, and site or association.
Why use leap seconds
if atomic time is so accurate, why use ____________? To achieve the highest possible level of accuracy, the International Bureau of Weights and Measures combines the output of about 400 atomic clocks in 69 national laboratories worldwide to determine TAI. The time scale is weighted, prioritizing the time signal provided by institutions that maintain the highest quality of primary cesium.
equipotential surface
in geodesy, a surface where the gravitational potential is the same at all points. The direction of the normal to an ________ coincides with the direction of the force of gravity, that is, with the plumb line. An example of an ___________ is the surface of a liquid in equilibrium.
Street type
in the address 1865 South Oak Ridge Lane which type of attribute is Lane
Satellite Errors
include ephemeride and clock errors
permanent tidal effect - the mean geoid
includes the direct effect of attraction and the indirect effect of deformation. it would coincide with an "undisturbed" sea level. an interest for oceanography
20 to 60 minutes
initial convergence time of PPP
TAI
international atomic time scale based on a continuous counting of the SI second. TAI is currently ahead of UTC by 37 seconds. TAI is always ahead of GPS by 19 seconds.
DOP
is a numerical representation of satellite geometry, and it is dependent on the locations of satellites that are visible to the receiver. The smaller the value of _____, the more precise the result of the time or position calculation
CSRS
is a three-dimensional grid on which positions (latitude, longitude and height) of any object or feature can be precisely pinpointed. The infrastructure underlying a grid consists of a network of points whose coordinates are determined with the highest precision. within this system a network of continuously operating GNSS receivers. CACS data support positioning accuracy at the decimeter-level (e.g. for imagery geocoding and realtime applications), the centimeter-level (e.g. for legal surveys) and the millimeter-level (e.g. for measuring crustal motion).
TAI
is a uniform time- scale of high accuracy. It corresponds to the definition of the SI second. Which has been made approximately equal to the second of the formerly used ephemeris- time
ITRS
is a world spatial reference system co-rotating with the Earth in its diurnal motion in space the IERS is in charge of providing global references to the astronomic, geodetic and geophysical communities, supervises the realization of the ________
constellation
is simply an orderly grouping of satellites, figure 11typically 20-30, in orbits that have been designed to provide a desired coverage, for example, regional or global.
Temps Atomique International
is the international atomic time scale based - Is one of the main components of Coordinated Universal Time UTC - Time scale used to determine local times around the world - tells us at which speed our clocks should tuck - is a time scale that used the combined output of some 400 highly precise atomic clocks. tells us the exact speed at which our clocks should tick
What are three factors that determine if an object is big enough to be seen on a remotely sensed image?
its size, and the spatial resolution of the sensor
Tropospheric Delay
layer of atmosphere closest to the surface of the Earth. Variations in tropospheric delay are caused by the changing humidity, temperature and atmospheric pressure in the troposphere. Since tropospheric conditions are very similar within a local area, the base station and rover receivers experience very similar tropospheric delay. This allows Differential GNSS and RTK systems to compensate for tropospheric delay.
ionosphere
layer of the atmosphere that most influences the transmission of GPS (and other GNSS) signals is the ________, the layer 70 to 1,000 km above the earth's surface. Ultraviolet rays from the sun ionize gas molecules in this layer, releasing free electrons. These electrons influence electromagnetic wave propagation, including GPS satellite signal broadcasts. __________ delays are frequency dependent so by calculating the range using both L1 and L2, the effect of the ________ can be virtually eliminated by the receiver.
Photogrammetry
making measurements from vertical air photos. Both horizontal (distance, anglesm areal extent) and vertical measurements (object height, angles, and elevation changes)
unambiguous
measurements based on the PRN modulation are ___________________, but precision is limited to sub- meter
ambiguous
measurements of the phase of the Carrier wave can be made to millimeter precision, but the measurement is ____________________ because of the total number cycles between the satellite and the receiver are unknown
a major road (such as virginia beach blvd) would be represented in a GIS as
multiple records, with each representing one piece of the road
A remote sensing device simultaneously measuring seven bands of energy wavelengths would be capable of producing which type of imagery?
multispectral
a remote sensing device simultaneously measuring 7 bands of energy wavelengths would be capable of producing what type of imagery
multispectral
A remote sensing device simultaneously measuring seven bands of energy wavelengths would be capable of producing which type of imagery?
multispectural
What are the main API applications?
municiple planning, forestry, infrastructure planning, surveys for mapping (NTS maps), environmental assessment, agriculture, geology, and many more
the location on the ground directly under the camera in aerial photography is referred to as?
nadir
Healthy vegetation reflects
near infrared
the energy range of 0.7 to 1.3 micrometers defines what types of energy
near infrared
When a satellite moves close to the north and south poles while it makes several passes a day about Earth, it is called
near polar orbit
TIGER files typically contain all of the following data except
number of houses per street
Why do we see objects in different colours?
objects reflect and absorb different wavelengths of light
In a(n) ____________ photo, the camera is tilted so that it's not positioned directly at nadir, but rather at an angle.
oblique
what type of aerial photo is taken when the camera is placed at an angle?
oblique photo
Multipath
occurs when a GNSS signal is reflected off an object, such as the wall of a building, to the GNSS antenna. Because the reflected signal travels farther to reach the antenna, the reflected signal arrives at the receiver slightly delayed. This delayed signal can cause the receiver to calculate an incorrect position.
Multipath
occurs when a GNSS signal is reflected off an object, such as the wall of a building, to the GNSS antenna. Because the reflected signal travels farther to reach the antenna, the reflected signal arrives at the receiver slightly delayed. This delayed signal can cause the receiver to calculate an incorrect position. to reduce __________ errors is to place the GNSS antenna in a location that is away from the reflective surface.
real time DGNSS
occurs when the base station calculates and broadcasts corrections for each satellite as it receives the data
What is meant by off-nadir viewing on the SPOT satellite? Identify two major reasons why the off-nadir viewing capability is useful in the acquisition of imagery.
off-nadir means that the sensor can tilt side to side to take a picture of something specific. 1) can focus on one area that is not directly underneath it in its flight path 2)
2. Which operation would best allow you to model a feature such as an elevated walkway joining two buildings over a busy city?
offsetting
BW Infrared
one active layer sensitive to all visible light and infrared light. Healthly vegetation absorbs most visible light, but reflects most infrared light.
disadvantage of single frequency
one has to rely on models, leading to residual errors. in the relative mode this effect is strongly attenuated
disadvantage of PPP
one needs dual frequency of some few hours to reach this high (sub cm) level of accuracy
control segment
one of the three segments of GPS consisting of the control stations that monitor the signals from the GPS satellites
space segment
one of the three segments of GPS consisting of the satellites and the signals being broadcast from space
RGB Colour Theory
our eyes see red, green, and blue. Plants phosynthesize visible light (hence their colour). This is called additive colour theory. Fliters are based on subtractive colour theory (if you want to filter out a certain colour, put the opposite coloured filter in front of the camera lens - yellow filter eliminates blue)
How long have images of the ground from the sky been captured?
over 150 years
__________ imagery only captures the visible portion of light in its entirety
panchromatic
a sensor that will be measuring only one wide band of wavelengths is which type of sensor
panchromatic sensor
Cell phone without flash=
passive remote sensing
landsat scenes are arranged according to the worldwide reference system, which indexes the scenes in a series of
paths and rows
the physical arrangement of items in an aerial image refers to
pattern
Datacenters
physically go to internet~ cables under (in) ocean carrying light wavelengths -landing station to landing station
What is a mixed pixel? How do mixed pixels affect the interpretation of an image?
pixel with several features in one. heterogeneous, not homogeneous.
linear interpolation is used in geocoding to
place a point an approximate distance alone a line
Linear interpolation is used in geocoding to
place a point an approximate distance along a line
The zero- geoid
preferred in geodesy, as the response of the earth to the permanent tidal part is not known. the attraction part is eliminated, but the permanent deformation retained. this definition takes into account the fact that positioning also refers to a deformed earth, with respect to a best fitting reference ellipsoid. the geoid deviates by about +-30 meters, in some cases +-100m
Applications of API in forestry
preparing forest type (v-type), working group, ecosite maps, locating access roads and corridors for primary to tertiary forest road development, assessing forest disturbances (fire, insect defoliation/disease, and plant stress), estimating tree or stand volume, timber sale and appraisal, monitoring forest changes and harvesting practices, management regulation and compliance, preparing harvest operations, conducting regeneration surveys, mapping wildlife habitat.
When looking down on an aerial photo, the center of the photo is referred to as its _____________ point.
principal
what is the center of an aerial photo referred to as?
principal point
Address standardization
process of setting up address components in a consistent way
digital elevation model
provide elevation in raster format for most of the Earth current cell size 100 to 1000 m on a side, ongoing project to map states using LiDAR in much greater detail (<1 m) commonly used to make TINs
What is a geostationary satellite? Are the Landsat satellites geostationary?
provides consistent data, but only on one spot. Landsat is not geostationary.
cross- correlating
pseudoranges are derived by __________ _______________ the pseudorandom noise code received from a satellite with a replica in the receiver
which has the lowest frequency: gamma rays, x-rays, infrared light, radio waves
radio waves
A sensor's ability to determine fine differences in a band of energy measurements is a sensor's
radiometric resolution
a sensor's ability to determine fine differences in a band of energy measurements is a sensor's
radiometric resolution
we see the sky as blue in the middle of the day because of
rayleigh scatterign
TAI
realized by over 200 monitoring stations around the world, maintained at 60 or so global stations
Describe (what colour is it?) and explain (why is it that colour?) the appearance of healthy green vegetation on a false colour composite image of Regina in summer.
red because chlorophyl is reflected strongly in NIR band. NIR band is displayed as red on the image.
What colours can RGB make?
red+blue = violet (purple); green+blue = cyan (turquoise); red+green = yellow; all three mixed together = white. All of the colour mixtures are affected by the bightness level of each colour; 50% red+ 50% green+ 50% blue = grey
The base network data used for geocoding is referred to as
reference database
the base network data used for geocoding is referred to as
reference database
Receiver Noise
refers to the position error caused by the GNSS receiver hardware and software. High end GNSS receivers tend to have less ________ _________ than lower cost GNSS receivers.
Which of the following is not a component of a geodatabase
relationship classes
th leaning of tall objects away from the center point of an aerial photo is due to
relief displacement
hyperspectral imagery
remotely sensed imagery comprised of the bands collected by a sensor capable of sensing hundreds of bands of energy at once.
multispectral imagery
remotely sensed imagery comprised of the bands collected by a sensor capable of sensing several bands of energy at once.
Byte:
represents 8 bits (bit= binary digit; 0, 1)
wetness index
represents the increased soil wetness due to large upslope areas and low slopes, includes analysis of profile v. plan curvatures w = ln(SCA/tan b) SCA = specific catchment area b = slope at the cell
differential positioning
requires a data link between the base station and rovers, if corrections need to be applied in real- time, and at least four GNSS satellites are in view of both the base station and the rover(s), then the computed position will depend on the absolute accuracy of the base station's position
Address matching
requires a reference layer, geo-locator tool, and an address list
RTK error elimination
requires measurements to be transmitted from the base station to the rover station
how to create allometric equations?
research. Conduct field work measuring biophysical parametres. Regression analysis.
DOP above 6
results in generally unacceptable accuracies for DGNSS and RTK operations.
a geostationary satellite
rotates at the same speed as the earth
Range corrections
rover stations receive GNSS signals, calculate pseudoranges, then apply _______ _____________. these are then used to determine accurate position
SBAS
satellite based augmentation system a method of using correction information sent from an additional satellite in the GPS position determination
RTK sources of error
satellite clock, ephemerides, ionospheric and tropospheric delays
non selective scattering
scattering of light caused by atmospheric particles larger than the wavelength being scattered.
Rayleigh Scattering
scattering of light caused by atmospheric particles smaller than the wavelengths being scattered.
Mie Scattering
scattering of light caused by atmospheric particles the same size as the wavelength being scattered.
Panchromatic
sensitive to ultraviolet, blue, green, and red light to ~0.7 microns
Address parsing is done to
separate the parts of an address
address parsing is done to
separate the parts of an address
SBAS or PPP
services which provide precise satellite clock information to account for attributing errors
drainage network
set of cells through which surface water flows, based on flow direction surface (exampe: convergent streams), completely contained within individual watersheds
PPP vs SBAS
similar to SBAS, PPP systems provide corrections to a receiver to increase position accuracy (PPP provide greater level of accuracy but charge a fee) PPP systems also allow a single correction stream to be used worldwide, while SBAS systems are regional
Antenna Beam width and Gain Roll-Off
specifies how much the gain changes over the elevation angle of the antenna. From the antenna's point of view, the satellites rise from the horizon towards zenith and fall back to the horizon. The variation in gain between zenith (directly overhead) and the horizon is known as the gain roll-off. Different antenna technologies have different gain roll-off characteristics.
The specific bands and wavelengths that a sensor can measure defines its
spectral resolution
the specific bands and wavelengths that a sensor can measure defines its
spectral resolution
A charted identifier for an feature based on its reflectance of different wavelengths of energy is a
spectral signature.
the first man made satellite to successfully orbit the earth
sputnik
placing the green band in the blue color gun and the red band in the green color gun and the near infrared band in the red color gun will create what type of composite image
standard false color
Setting up the components of an address in a regular format describes
standardization
Destinations to visit on a network are referred to as
stops
destinations to visit on a network are referred to as
stops
how often a satellite can return to image the same area on the ground is a measure of that sensor's
temporal resolution
Forest species identification: use of your knowledge of:
terrain analysis, landforms, soild types, forest silviculture
the differences of a certain tone throughout an aerial image (degree of roughness or smoothness) refers to
texture
1. Graphics that can be applied to the faces of an object provide a more realistic appearances are:
textures
End Lap
the 60% overlap between neighbouring air photos (stereo pair, stereotriplet, or stereogram). This permits stereo viewing of all the surface areas when using a stereoscope.
GRS80
the CGG2013 provides separation between the ________ _____________ and the equipotential surface
EROS
the Earth Resources Observation Science Center; located outside Sioux Falls. South Dakota which serves (almong many other things) as a downlink station for satellite imagery.
ETM+
the Enhanced Thematic Mapper sensor onboard landsat 7
Galileo
the European union's GNSS currently in development
MISR
the Multi-Angle imaging SpectroRadiometer Instrument onboard Terra.
geodetic survey division
the NRCan branch associated with maintaining CGVD2013
OMI
the Ozone Monitoring Instrument onboard Aura.
Ambiguity Fixed Solution
the RTK roving receiver is computing ?
TM
the Thematic Mapper sensor onboard landsat 4 and 5
Coordinate Systems
the X,Y coordinate systems for map data
optical fringes
the __________ _____________ generated in the interferometer (FG5) provide a very acc
Spatial Resolution
the ability of a sensor to render a clearly defined image or the smallest object that can be seen by a sensor.
What is remote sensing?
the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to in situ observation.
if an address is matched to the correct street segment but the wrong location on that street, the problem could be
the address ranges in the reference database do not match the actual street address ranges in the real world
When does the shadow method work best?
the air photo was taken under strong lighting conditions (bright sunlight creates dark shadows), the object has clearly seen top edges/point, the object is nearly vertical, there is flat ground, little understory or snow, the object is close to nadir.
ambiguities
the aligning of GPS signals (wavelengths) of an unbroken series of measurements of the carrier phase frequency by a GPS receiver
Astronomic Latitude
the angle between the plane of the earth's equator and the plumb line (direction of gravity) at a given point on the earth's surface
Ellipsoidal Longitude
the angle measured in the equatorial plane between the Greenwhich and the ellipsoidal meridian at point P. Reckoned positive east
Horizontal Angle
the angle measured in the horizontal plane of the local astronomic system between two vertical planes. formed by the difference in horizontal directions to the target points, which define the vertical planes
What does the term parallax refer to?
the apparent change in relative positions of a stationary object caused by the change in the viewing position (ie objects in the foreground appear to move more then the background) NOTE: in vertical air photos parallax displacement occurs only parallel to the flight line (along the x-axis)
pattern
the arrangement of objects in an image interpretation.
Air photo Interpretation Definition
the art and science of IDENTIFICATION of objects by their images, and DETERMINING THEIR MEANING AND SIGNIFICANCE. or the systematic visual examination of imagery to identify, interpret and determine the significance of results applied to a problem
spectral resolution
the bands and wavelengths being measured by a sensor.
reference database
the base network data used as a source for geocoding
Pseudorange
the calculated distance between a GPS satellite and a GPS receiver
pseudorange
the calculated distance between a GPS satellite and a GPS receiver (T x C)
off-nadir viewing
the capability of a satellite to observe areas other than the ground directly underneath it.
principle point
the center point of an aerial photo
in order to match an address to a particular street location, what fields are necessary to have in the reference database
the city name and zip code of the street address
Association
the co-occurance of certain features in relation to each other. ie. what things would be expected to occur near already identified objects
ephemeris
the computation of gps location is based on the known ___________ of the satellites and the intersection of spherical shells.
CORS
the continuously operation reference stations a system operated by the national geodetic survey to provide a ground based method of obtaining more accurate GPS positioning
the u-2 aircraft's remote sensing capabilities were especially proven during which event in history?
the cuban missile crisis
C/A code
the digital code broadcast on the L1 frequency, which is accessible by all GPS receivers
In a TIGER file the FEDIRP field refers to
the direction of the prefix of the street
wavelength
the distance between the crests of two waves.
Ellipsoidal Height
the distance measured from the ellipsoid to surface point p along the ellipsoid normal
relief displacement
the effect seen in aerial imagery where tall items appear to bend outward from the photo's center toward the edges.
Gravitation anomaly
the elevation difference between a standard shape of the earth (ellipsoid) and a surface of constant gravitation potential (geoid)
brightness values
the energy measured at a single pixel according to a pre-determined scale. Also referred to as Digital Numbers.
Landsat 5
the fifth landsat mission launched in 1984, which carries both the TM and MSS sensors.
Terra
the flagship satellite of the EOS program
GLONASS
the former USSR's GNSS currently rebuilding to a constellation of satellites
texture
the frequency of the tonal variation for a given object or region on the air photo. Texture is prodiced by an assembly or region of features to small to be identified individually. Image texture changes as scale changes.
constellation
the full complement of satellites comprising a GNSS
10.23 MHz
the fundamental frequency of atomic clocks on GPS satellites
shape
the general form, configuration, or outline of the individual objects. When viewing in 3D, height can also be considered. Must remember that you are viewing the object from nadir, which can be an unfamiliar vantage point.
site
the geographic location of the object (physical and social characteristics). Knowing geography of the study region can provide many clues as to the expected types of land cover or activities
gnss
the global navigation satellite system, an overall term for the technologies using signals from satellites for finding locations on the earth's surface
worldwide reference system
the global system of paths and rows that isued to identify what area on earth's surface is present in which landsat scene.
GloVis
the global visualization viewer set up by the USGS for viewing and downloading satellite imagery.
spatial resolution
the ground size represented by one pixel of satellite imagery.
Hyperion
the hyperspectral sensor onboard EO-1
Spatial
the information handled by GIS is primarily
selective availability
the intentional alteration of the timing and position information transmitted by a GPS satellite
estimating
the key to achieving precise positioning with RTK or PPP
LDCM
the landsat data continuity mission- the future of the landsat program, scheduled to be launched in 2012
electromagnetic spectrum
the light energy wavelengths and the properties associated with them.
connectivity
the linkages between edges and junctions of a network
nadir
the location under the camera in aerial photography
Sea Surface Topography
the ocean surface does not coincide with the level surface (geoid) of the earths gravity field. the deviations are called ___________, also known as dynamic ocean topography
a sun synchronous orbit indicates
the orbit is set up so that an area on the ground is imagd at the same time of day
UV
the portion of the electromagnetic spectrum with wavelengths between 0.01 and 0,4 micrometers.
visible light spectrum
the portion of the electromagnetic spectrum with wavelengths between 0.4 and 0.7 micrometers.
PDOP
the position dilution of precision it describes the amount of error due to the geometric position of the GPS satellites
DGNSS
the position of a fixed GNSS receiver (base station), is determined to a high degree of accuracy using conventional surveying techniques, then the base station determines ranges to the GNSS satellites in view using - code based positioning technique - the location of the satellites are determined precisely, as they are known from orbit ephemerides and satellite time
geopotential numbers
the potential energy differences between 2 points. if they are the same, water will not flow between them
remote sensing
the process of collecting information related to the reflected or emitted electromagnetic energy from a target by a device a considerable distance away from that target from an aircraft or spacecraft.
remote sensing
the process of collecting information related to the reflected or emitted electromagnetic energy from a target by a device a considerable distance away from the target onboard an airborne or spacecraft platform.
Visual image interpretation
the process of discerning information to identify objects in an aerial (or other remotely sensed) image.
photogrammetry
the process of making measurements using aerial photos
photogrammetry describes
the process of obtaining measurements from an aerial photo
blue band
the range of wavelengths between 0.4 and 0.5 micrometers
green band
the range of wavelengths between 0.5 and 0.6 micrometers.
red band
the range of wavelengths between 0.6 and 0.7 micrometers
attenuation
the reduction of the amplitude of a signal, electric current, or other oscillation
in active remote sensing
the remote sensing device generates its own source of energy and measures the reflection or return of that particular type of energy
photo scale
the representation used to determine how many units of measurement in the real world are equivalent to one unit of measurement on an aerial photo.
shortest path analysis
the route results from the lowest cost between stops
Remote Sensing
the scanning of the earth by satellite or high-flying aircraft in order to obtain information about it.
Environmental Informatics
the science of how to apply info to data pertaining to natural environment and obtain, manage, process, interpret, communicate information pertaining to one or many aspects of the natural environment *There is a ton of data out there, coming in so quickly that we need computers to help handle and convert it into information
Geodesy
the shape of the earth and definitions of earth projections
True
the shortest path between two locations is based on criteria determined by the person who is using the vehicle navigation system
spatial resolution
the size of the area on the ground being represented by one pixel's worth of energy measurements.
Pattern
the spatial arrangement of objects. Can be regular, linear, random, clumped. Usually describes the arrangement of a group of objects, or at a scale larger than the objects being described
incident energy
the total amount of energy (per wavelengths) that interacts with an object.
Map Projection
the transformation of a curved earth to a flat map
TAI and UT1
the two components that are used to determine Coordinated Universal Time UTC
Time Systems
the unit for a time interval and by a time epoch. They are based either on the definition of the SI second or on the diurnal rotation of the earth about its axis
navstar gps
the united states global positioning system
WAAS
the wide area augmentation system a satellite based augmentation system that covers the US and other portions of North America
swath width
the width of the ground area the satellite is imaging
UTC (coordinated universal time)
the worlds time standard -basis for civil time today - 24 hour time standard that is kept using highly precise atomic clocks, combined with the earths rotation
GPS monitoring stations
these 5 globally distributed stations are equipped with cesium standards and GPS receivers. they take continuous measurements of Pseudoranges to all satellites and transfer the results to the master station -- after computation of the satellite orbits and the clock correction, the extrapolated broadcast ephemeris and GPS time are transmitted to the satellites for storage and retransmission by three ground antennas collocated with monitoring stations
Coarse Acquisition C/A
this code is modulated on L1 carrier only, with a frequency of 1.023 MHz (approx 292 m wavelength) and a repetition rate of 1 ms
Phyisical definition of the Geoid
this considers the waters of the oceans as freely moving homogenous matter, subject only to the force of gravity and free from variations with time. upon attaining a state of equilibrium, the surface of such idealized oceans would assume a level surface of the gravity field. the ocean surface could be regarded as being extended under the continents (eg a series of conduit tubes)
Site Selection for RTK
this is important for minimizing environmental effects such as interference and multipath, as is the quality of the base station and rover receivers and antennas
atmospheric windows
those wavelengths of electromagnetic energy in which most of the energy passes through Earth's atmospheric.
What are some recognition elements?
tone/colour, pattern, texture, shape, size, association (branching characteristics, crown shapes, shadows, spatial distributionpatterns)
specific catchment area
total area draining to a point relative to drainage width SCA = Area/C, where Area = accumulated area upstream C = raster cell dimension
A map projection is a
translation of locations on the Earth's surface to their corresponding locations on a flat surface.
energy passing thru a target material describes what
transmission
L1
transmits a navigation message
What variables can be measured directly from air photos using interpretation, measurement tools, guides?
tree or stand height, visible stand diametre, degree of stocking (stem density), percent crown closure. Many of the most important tree or stand characteristics CANNOT be measured directly on aerial photographs. They must be ESTIMATED through statistical techniques (ie regression analysis) using tree or stand characteristics that can be measured directly.
Being able to examine CIR imagery is very useful in environmental studies
true
Terra's orbit is synchronous with the sun.
true
placing the blue band in the blue color gun and the green band in the green color gun and the red band in the red color gun will create what type of composite image
true color
Which of the following forms of electromagnetic energy has the shortest wavelength?
ultraviolet light
UT1
universal time corrected for polar motion. Universal time is not constant and must be corrected for changes in polar motion. Parameters are provided by the IERS
Today, digital aerial photography is obtained by _____________ aerial vehicles
unmanned
UAV
unmanned aerial vehicle- a reconnaissance aircraft that is piloted from the ground via remote control.
Why can we say that an unsupervised classification can never be wrong?
unsupervised classification
what do you you use for species mapping?
use interpretation guides, or interpretation keys
SLR and LLR
use short-pulse lasers and state-of-the-art optical receivers and timing electronics to measure the two-way time of flight (and hence distance) from ground stations to retroreflector arrays on Earth orbiting satellites and the Moon.
navigation message
used both L1 and L2 carriers for two code modulations and for data signal
Ephemerides
used for real time satellite coordinate computation, which is required in position computation
rubidium clocks
used in latest generations of GPS satellites, accurate to within ±5 parts in 10^11. synchronized by moreaccurate ground-based cesium clocks
stream power index
used to identify the potential erosion of a point, depending on upstream area and local slope SPI = SCA * tan (b) SCA = Specific Catchment Area b = slope at the cell
Precise Ephemeris
user accesses this by post- processing their raw data using the CSRS-PPP service provided by NRCAN -- submitting a RINEX file online data is processed using precise orbital information and clock informations NRCAN is responsible for determining the precise ephemeris and this is accomplished using the CACS system accurate to +-1 cm
Broadcast Ephemeris
user accesses this through the navigation message that is modulated on the L1 and L2 frequencies the receiver extracts the ephemeris from the navigation message and uses the information to determine the location of each satellite in the sky in order to calculate its position on earth
NAD27 ELLIPSE
uses Clarke (1866) _______ on a non geocentric axis of rotation
WGS84 ELLIPSE
uses GRS80 ________, almost same as NAD83
NAD83 ELLIPSE
uses GRS80 _________ on a geocentric axis of rotation
DGNSS
uses a base station and compares the surveyed position to the position calculated from the satellite ranges
LiDAR
uses lasers mounted on aerial or satellite-based systems to measure ground elevation Heights are then used to create a TIN or grid-based DEM
RTK
uses pseudorandom codes transmitted by four or more satellites to determine the ranges to the satellites from these ranges and knowing where the satellites are, the receiver can establish its position to within a few meters
UTM
uses the TM projection - each zone has a central meridian (lo), zones are 6° wide, and go from pole to pole - 60 zones cover the earth from east to west - reference latitude is at the equator - (Xshift, Yshift) = (xo,yo) = (500000, 0) in the Northern Hemisphere, units are meters
networks analysis
using a series of interconnected links and junctions (represented by nodes) to calculate routes through a network
street centerline
usually used as a reference layer in geocoding
Ephemerides
valid two hours before and two hours after time of acquisition (toe), the toe can be thought of as when the data was computed from the GNSS control segment
what kind of photo is taken from a camera looking straight down at the ground
vertical photo
how are UAS's flown? (unmanned aircraft system)
via remote control from the ground
A data layer that determines a persons visibility from a location before his or her view is blocked by the terrain
viewshed
Big Data
volume variety velocity value
adjustment of UTC
was adjusted several times until 1972 when leap seconds were introduced to keep UTC in line with the Earth's rotation, which is not even, and less exact than atomic clocks
IERS
was created in 1988 to establish and maintain a Celestial Reference Frame
What is light?
wavelengths/radiation within the visible spectrum
What can we determine using parallax measurements?
we can determine the elevation difference between the datum and the given point.
What is a fundamental premise upon which much of remote sensing is built?
we can identify and learn about objects and features on the Earth's surface by studying the spectral characteristics of the radiation reflected by these features. We interpret an image based on its colour.
seismic isolation
what does the superspring provide in the gravimeter? this is for the reference optic to improve the noise performance of the FG5
1575.42
what is the L1 Megahertz frequency? at 19.05cm wavelengths?
1227.60
what is the L2 Megahertz frequency? at 24.45 cm wavelengths?
What are the key questions when designing an API project?
what is the purpose of the study? what is the best type of film product? what is the optimal scale (expected detail)? What is the local relief (expected relief displacement - lower flight more displacement)? What is the optimal time of acquisition (hour, season)?
float
when determining ambiguities, the receiver sets interger values to individual wavelengths- the interger values are then set to a ________ valye and statistically analyzed using a LSA
absorption
when light is trapped and held by a target.
transmittance
when light passes through a target
permanent tidal effect - the non-tidal geoid
where the total wide effect would be eliminated. agreeing with the theoretical demand of geodesy to have no masses outside the boundary of the "geoid"
NRCAN and CACS
who maintains the CGVD2013?
superspring
with gravimeters, the free-fall trajectory of the dropped object is referenced to a very stable active- spring system called a _______________?
describe the importance of base heights and spatial reference information in properly placing 3D objects in their correct position on the Earth's surface
ya need it to make sure ya got the right datum
