GEOG 201 final exam

our eyes are sensitive to viewing what wavelengths of light

0.4 mircometers - 0.7 micrometers

list and use the spatial cues needed for aerial photo interpretation

1) pattern: the arrangement of objects in an image 2) site and association: the info referring the location of objects and their related attributes in an image 3) size: physical dimensions (length, width, and area on the ground) of objects 4) shadow: dark shapes in an image caused by a light source shining on an object 5) shape: the distinctive form of an object 6) texture: repeated shadings or colors in an imaged 7) tone: the grey scale levels (from black to white) of range of intensity of a particular color discerned as a characteristic of particular features present in an image

the vertical accuracy of lidar models of terrain is about

15-30cm

landsat 8's sensor has the capability to see the same area on the ground every

16 days

a typical landsat TM scene measures about

170 x 183km

landsat 8's program has been active since what year

1972

what is the representative fraction indicating the largest scale map?

1:1

what is the difference between the NAD 83 and NAD 27 datums

27 was created using surveys and 83 with satellites

landsat 8's multispectral imagery is at what resolution

30m

many 3D models are available to use in Google Earth and SketchUp via

3D warehouse

what is the minimum number of GPS satellites needed to infer your correction location

4

a 1:24000 scale topo map will show how much geographic area

7.5 min lat x 7.5 min lon

electromagnetic spectrum

All of the frequencies or wavelengths of electromagnetic radiation

summarize how digital numbers are displayed on screen and in maps both in black and white and color

As the values for the reflected wavelength of the light received by the sensor changes, the values are assigned to different colors or shades of black and white that are then plotted on maps

which of the follow uses a rule-based design for quickly rendering 3D buildings

CityEngine

Define the spatial concept of connectivity when modeling a network

Connectivity is essential to modeling GIS. With proper connectivity, all junction and edges should properly connect to one another, while other things that should not connect do not connect. For example, if a freeway crosses over a road via an overpass, the network connectivity should not allow a valid junction where the street is able to access the freeway.

a digital terrain model that consists of regularly sampled points of elevation is

DEM

Describe what a DEM and TIN are and how they differ in their representation of the vertical dimension.

DEM: digital elevation map; a representation of the terrain surface, crated by measuring a set of equally spaced elevation values TIN: triangulated irregular network; a terrain model that allows for non equally spaced elevation points to be used in the creation of the surface - selected elevation points of the terrain, those that are 'most important' are used

the use of a base station or other earth bound source to transmit a correction signal to a GPS receiver refers to

DGPS (differential GPS)

Describe how the process of address matching or geocoding enables you to derive a spatial location (a geocoded x, y location)

First, a reference database needs to be in place - this is a road tework that the addresses will be matched to. This info will be used as the source to match addresses to as well as a source for the final plotted map. Next, the address info is subjected to parsing - breaking it up into its components. Then the addresses undergo address standardization so they are all in the same format. Finally, the matching process takes place. Sometimes in GIS batch matching is used where a group of addresses are matched to locations together.

Describe how junctions and edges are used to represent real world networks

For example, in a road network, junctions might be the starting and ending points of a road, or they might be points of intersection with other roads. The edges are the lines that represent the roads themselves

the current generation of topographic maps produced by USGS are

GeoPDF versions of US Topos

KML and KMZ files are the native file formats used to work with 3D objects in

Google Earth

the energy range of 0.7-1.3 micrometers defines what type of energy

NIR

describe the history and different types of aerial photography

The first aerial photo was taken by a Frenchman from a hotair balloon in 1858. Photography equipment was since attached to balloons and kites to take photos. Aviation began in 1903 and in 1908 the first photo was taken from a plane. Starting with WWI aerial photography from planes was used for map making and planning military tactics. It continued to be important throughout WWII. 1950's saw development of U-2 spy planes (vertical photos). Today aerial photos are obtained from unmanned crafts. - vertical photos -CIR photos -orthophotos -oblique photo

TIGER files are created and maintained by

US Census Bureau

datum used by gps

WGS84

Tiger Line Files

a file produced by the US Census Bureau that contains (among other items) the line segments that correspond with roads all over the US

block

a flat polygon that has been extruded to transform it into an object with a z value

in a GIS network, an edge represents

a link on the network

digital surface model (DSM)

a measurement of the heights of ground elevations as well as the objects on top of the ground as captured by lidar

bands

a narrow range of wavelengths that may be measured by a remote sensing device (blue, green, red, IR, NIR, SWIR)

lidar

a process in which a series of laser beams fired at the ground from an aircraft is used both to create highly accurate elevation models and also to measure the height of objects from the ground

digital elevation model (DEM)

a representation of the terrain surface, created by measuring a set of equally spaced elevation values

digital raster graphic (DRG)

a scanned version of a USGS topographic map

network

a series of junctions and edges connected together for modeling concepts such as streets

hillshade

a shaded relief map of the terrain created by modeling the position of the Sun in the sky relative to the landscape

offset

a value applied to an object that is not attached to the ground, but is entirely above ground level

relative fraction

a value indicating how many units of measurement in the real world are equivalent to how many of the same units of measurement on a map

transit cost

a value that represents how many units (of time or distance) are used in moving along a network edge

small scale maps would use

a wider contour interval than large scale maps

energy trapped and held by a surface has been

absorbed

Describe how distortion is distributed in aerial photos, and how representative fractions (RF) capture the relationship between ground and photo distance across an orthorectified image

aerial photos experience relief displacement where tall items appear to bend outward from the photos center toward the edges. the principal point of an aerial photo is the center of the photo where there is no displacement. A photo scale is often used to determine how many units of measurement in the real world are equivalent to one unit of measurement on an aerial photo. This is a similar concept to RF (representative fraction). Using the photo scale you can determine the real-world size of features

in hillshading you set which two parameters?

altitude of the sun and its location relative to earth

orthophoto

an aerial photo with uniform scale

contour line

an imaginary line drawn on a map to connect points of common elevation

in a GIS network, a junction represents

an intersection on the network

viewing an image that is offset in both the color red and the color blue that enables a '3D' style effect is

anaglyph

which operation would best allow you to place 3D buildings at their proper height on the terrain

applying base heights

in the raster data model

areas are modeled using equally spaced and equally sized grid cells

Describe what aspect and slope represent

aspect is the cardinal direction that the terrain is facing slope is a quantitative value for how steep the terrain is at a given location calculated by rise/run

describe the importance of base heights and spatial reference info in properly placing 3D objects in their correct positions on earth's surface

base heights are the elevation values assigned to the terrain upon which objects are placed. terrain base heights must be applied to objects as well when they are being built so that objects are placed in the correction location in space

multiple addresses can be geocoded at once via

batch coding

panchromatic

black and white aerial imagery

List wavelength domains in the EM spectrum that are important for remote sensing

blue band green band red band IR NIR (near infrared) SWIR (shortwave infrared)

address parsing

breaking an address up into its component parts

a DSM can be used to determine

building heights

Describe how illumination source azimuth and altitude influence patterns of light and dark in a hillshade

by setting values for sun altitude and sun azimuth the terrain can take on various appearances to simulate how the landscape looks at different times and in different conditions during the day. this influences what the hillshade, or a shaded relief map of the terrain modeling the position of the sun in the sky relative to the landscape, will look like

pre-made 3D objects in SketchUp are referred to as

components

Describe key terms in topographic maps

contour: the lines drawn on a map that connect points of common elevation contour interval: the vertical difference between two adjacent contour lines

The series of ground stations that help maintain GPS refers to which component of GPS?

control segment

a digital orthoquad (DOQ)

covers 3.75 minuteslat by 3.75 min lon

when modeling in GIS, when all features are treated as objects with definitive locations and boundaries, what is being described

discrete object view of the world

in UTM coordinates, as you walk southeast what happens to your coordinates

easting increases, northing decreases

in developing a GIS database of spatial data, which model of Earth's surface is used to develop the spatial reference of a datum

ellipsoid

which of the following do you not need to know to find your location in lat and lon ellipsoid origin of the projection datum

ellipsoid

which of operation would best allow you to model a feature such as creating a footprint of your house and showing the house at the proper height?

extrusion

describe the difference between 2.5D and 3D spatial data

if only one height value can be assigned to an (x,y) pair then the data is 2.5D. if multiple height values can be assigned to an (x,y) location then the data is 3D

lidar uses which of the following to create a digital terrain model

laser beams

what is an example of a thematic map?

map of a neighborhood showing which houses are rentals and which are not

slope

measurement of the rate of elevation change at a location, found by dividing vertical height by the horizontal length

when the gps signal bounces off objects to arrive later than anticipated which type of error is occurring?

multipath

the location on the ground directly under the camera in aerial photos is referred to as

nadir

a parcel map of Mahoning county listing the owner of each land parcel would mean those polygons represent what type of data

nominal

on which type of data would it make no sense to apply the > opperator

nominal

what map projection eliminates all distortions

none

NDVI

normalized difference vegetation index; a method of measuring the health of vegetation using near-infrared and red energy measurements

TIGER files typically contain what type of data?

number of houses per street

what type of aerial photo is taken when the camera is placed at an angle

oblique photo

which operation would best allow you to model a feature such as an elevated walkway joining two building over a busy city?

offsetting

list how reflected light is quantified and recorded in different portions of the EM spectrum

panchromatic photos just use black and white, CIR photos are used to represent the IR light being reflected

the physical arrangement of items in an aerial photo refers to

pattern

linear interpolation is used in geocoding to

place a point an approximate distance along a line

the National Agriculture Imagery Program (NAIP)...

produces orthoimages of the entire US

what data classification method attempts to place an equal number of data values in each class

quantiles

A sensor's ability to determine fine differences in a band of energy measurements is a sensor's

radiometric resolution

what type of data set is used to represent the NLCD (national land cover database)

raster data model

rational opperators and boolean opperators

rational: equal, not equal, less than, greater than boolean: and (intersection), or (union), not (negation), xor (exclusive)ras

in an attribute table each object is stored as a

record

NDVI utilizes what two bands

red and NIR

in a CIR photo

red energy is displayed as the color green green energy is displayed as the color blue NIR energy is displayed as the color red

the 'leaning' of tall objects away from the center point of an aerial photo is due to

relief displacement

describe how multispectral instruments quantify and record the spectral dimensions of info (radiometric resolution and spectral resolution)

sensors scales the energy measurements into several different ranges. the radiometric resolution is the degree of a sensor's ability to determine fine differences in a band of energy measurements

The specific bands and wavelengths that a sensor can measure defines its

spectral resolution

what is not a commonly used developable surface in map projections

spherical

a file containing line segments representing roads is a

street centerline file

the tool used for viewing imagery at a particular location on a road is

street view

the difference of a certain tone throughout an aerial image refers to

texture

graphics that can be applied to the faces of an object to provide a more realistic appearance are

textures

How is Navstar GPS used for route finding

the GPS is integrated with a network database to provide a vehicle navigation system

in order to match an address to a particular street location, what fields are necessary to have in the reference database?

the address ranges on the right and left side of the street

reference database

the base network data used as a source for geocoding

in active remote sensing...

the device generate its own source of energy and measures the reflection or return of that particular type of energy

in a TIGER 2000 file, the FEDIRP field refers to

the direction of the prefix of a street

aspect

the direction that a slope is facing

extrusion

the extending of a flat object to have a z value

connectivity

the linkages between edges and junctions of a network

edges

the links of a network

point cloud

the name given to the massive number of elevation data measurements collected by lidar

junctions

the nodes (or places where the edges come together) in a network

a sun synchronous orbit indicates

the orbit is set up so that an area on the ground is imaged at the same time of day

orbit

the path a satellite follows around the Earth (geostationary; the object follow precisely the direction and speed of Earth's rotation and is therefore always directly over the same point on Earth's surface)

spectral reflectance

the percentage of the total incident energy that was reflected from that surface

near-infrared

the portion of the EM spectrum with wavelengths from 0.7-1.3 mircrometers

the center of a vertical photo is called

the principal point

visual image interpretation

the process of examining info to identify objects in an aerial (or other remotely sensed) image

photogrammetry describes

the process of obtaining measurements from a photo

geocoding

the process of using the text of an address to plot a point at that location on a map

describe why surface materials have different spectral properties (spectral signatures)

the reflectance properties of and object depend on the material and its physical and chemical state, the surface roughness as well ans the geometric circumstances (incident to the sun)

describe components of satellite orbit that affect what can be collected with satellite imagery (temporal v spatial resolution)

the type of orbit and the swath width affect these factors. The orbit affect the temporal resolution. geostationary orbit will be over the same location always, but near-polar orbit and sun-syncronous have different temporal resolutions. the swath width affect the spatial resolution. also, along-track scanning and across-track scanning (scanning method using rotating mirror to collect data across the width of the swath) can change the spatial resolution.

by applying vertical exaggeration to a model...

the vertical scale is made larger than the horizontal scale

swath

the width on the ground area the satellite is imaging as it passes over Earth's surface

describe what a z value means in the context of geospatial data

the z direction gives height or a vertical component to objects which helps to convert objects from 2D to 2.5D or 3D and closer to reality

what signal is transmitted by a GPS satellite to your handheld receiver

time

the greyscale levels or intensities of particular colors in an aerial image refers to

tone

resolution of a raster cell refers to which dimension

total length of one side of the cell on the ground

a map projection is

translation of locations on Earth's surface to their corresponding locations on a flat surface

energy passing through an object describes

transmission

Placing the blue band in the blue color gun, the green band in the green color gun, and the red band in the red color gun will create which type of composite image?

true color

the SRTM performed what

used radar waves from space to map the terrain surfaces of the earth

route-finding

using different meteric to determine the best route - i.e. shortest path, transit cost, stops

a photo taken from a camera looking straight down at the ground is a

vertical photo

unmanned aircraft systems (UAS) are flown

via remote control from the ground

how features are displayed on a map to emphasize their level of prominence describes

visual hierachy

describe how extrusion relates to true 3D representations of geospatial data

when an object is extended in the z direction, then there are multiple z values for one (x,y) location on the surface. this requires that the data be represented in true 3D

color-infrared

(CIR photo) 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