GISP: All Sets (1-10 and Extra)
Atlas*GIS
(an evolutionary stage in the development of GIS) Desktop mapping system -combined some functions of CAD with simple linkages between location data and attribute data. -some desktop mapping systems supported simple, single attribute file queries
How do you produce an acceptable PDOP?
- collect data when there is optimum satellite availability (4+) AND -when satellites are in an appropriate configuration
What are TABLES (in context of database object relationships)?
- collection of related data held in structured format within a database -contains fields and rows
What is the SPIRAL DEVELOPMENT application development method?
- combination of waterfall and RAD - advantages of both top-down and bottom-up concepts
What is Semantic translation?
- concerned with converting the meaning inherent in geographic information.
What is the TEXT field type?
- could be a coded value - assign to an integer through a domain
What is Web Services transfer construct?
- data is accessed/exchanged over networks and internet between software components -uses http and other web based protocols.
What is a file-based transfer?
- data is in a structured file format.
What are DATABASE LINKS (in context of database object relationships)?
- data stored in a different database but accessible to the database currently being accessed
Describe an Integrated enterprise?
- data stored in big business systems to extend their analytical capabilities -weave together and integrate traditionally disparate business functions (e.g. property ownership, utility infrastructure, and emergency response)
What is AUTHENTICATION in the context of database security?
- database checks the list of users to make sure a user is allowed to make a connection
What is the role of user access in database security?
- database must verify user accounts that connect to it.
What is an Elevation Mask?
- default angle to minimize amount of atmosphere through which satellite signal must travel - set it to 15 degrees
What is the function of the part of the expression where "Select" is in the expression SELECT * FROM Table WHERE "EXPRESSION"?
- determines what the operation will be -in this case, the operation is SELECT
What is the AGILE application development method?
- developing software in mini-increments of the new functionality - i.e. 2 week sprints -example types of Agile *scrum *crystal *extreme programming (XP) *feature-driven development
What is a DISTANCE FROM BASE STATION GPS error?
- differential correction will increase the quality of the data -accuracy is degraded slightly as the distance from the base station increases
What is an ATTRIBUTE DOMAIN (in context of database object relationships)?
- enforces data integrity -identify what values are allowed in a field
What is the simplest definition of SECURING DATA?
- flexibility and control over how GIS platform is deployed, maintained, secured, and used
What role does .shp.xml play in a Shapefile?
- geospatial metadata in XML format
What is Internet Protocol (communication packet interval)?
- header is added at the internet layer
What is the function of the part of the expression where "*" is in the expression SELECT * FROM Table WHERE "EXPRESSION"?
- indicates the fields that should be returned -the asterisk (*) denotes that all fields should be returned
What is the function of the part of the expression where "FROM Table" is in the expression SELECT * FROM Table WHERE "EXPRESSION"?
- indicates which table or feature class the data should be selected from
What is Data Quality Information (in metadata)?
- information about processes and sources used to develop the data -positional and/or accuracy assessments performed.
What is the function of the part of the expression where ""WHERE "EXPRESSION"" is in the expression SELECT * FROM Table WHERE "EXPRESSION"?
- is a filter on the table or feature to indicate what records should be returned -ArcGIS and QGIS typically only request users to only fill out the "EXPRESSION" portion e.g. "Street = 'MAIN'
What is meant by "Deceptive Mapping"?
- maps can be distorted for propaganda, military protection, or ignorance
Describe Computational Modeling (in terms of measurement)?
- models as simplified representations of reality
Describe Qualitative Data
- nonnumerical OR -numerical values that have no quantitative meaning (nominal)
What is the GEOMETRY field type?
- point, line, polygon, multipoint, multipatch
What is a TRIGGER (in context of database object relationships)?
- procedural code automatically executed in response to certain events on a particular table or view in a database
What role does a .prj play in a Shapefile?
- projection format
What is a GEO-TIFF?
- puts latitude/longitude at edges of pixels
What is the RASTER field type?
- raster can be stored within the geodatabase
Describe TEMPORAL RASTER RESOLUTION
- repeat cycle / frequency with which images are collected for the same area
What are VIEWS (in context of database object relationships)?
- result from stored query on the data - users can query - when view is accessed, virtual table computed dynamically from data
What is the PUBLIC ROLE in the context of database management?
- right granted to anyone connected to database
What are query expressions?
- select a subset of features or records
What are FUNCTIONS (aka SUBROUTINES) (in context of database object relationships)?
- sequence of program instructions that perform a specific task
What role does .shp play in a Shapefile?
- shape format - feature geometry itself
What role do .sbn and .sbx play in a Shapefile?
- spatial index
What is a SNAPSHOT (in context of database object relationships)?
- state of a system at a particular point in time - can be a backup
What is the simplest purpose of a Geodatabase?
- stores GIS in central location for easy access
What is ArcInfo Coverage (vector format)?
- stores set of thematically associated data considered to be a unit
What is a SCHEMA (in context of database object relationships)?
- structure or design of the database or object - defines tables, fields in each table, relationships between fields - will include information on which fields have domains and what those domains are
What is a DOMAIN (in context of database object relationships)?
- the range of values for a particular metadata element
What is the definition of a Data Owner?
- the user who creates tables, feature classes owns those datasets.
What is the REQUIREMENTS PHASE of systems architecture design?
- user needs assessment -workflow loads analysis
What are VARIABLES (in the context of Scripting)?
- value that can change depending on program or information passed to program e.g. x = 2 x is the variable, the value 2 is assigned
Where are the edges in a geographic coordinate system?
-/+180 for the EW extents -/+90 for the NS extents
What is resolution of AFPO scanned imagery?
-0.5 meters -12.5 microns -2136 DPI
How is the board of directors of GISCI made up?
-10 people total -Two people from each contributing organization
When did the development of digital mapping and CAD systems first begin and by whom?
-1950s and 60s -engineers, computer scientists, geographers, other innovators
What were (and in what decade) the first steps taken to move away from hand drawing/engraving maps?
-1980s -Adopt CAD in place of drafting.
How many service levels does the US Global Positioning System (GPS) provide?
-2 -SPS -PPS
Circumcircle (relative to Voronoi diagram)
-A circle that intersects each of a triangle's vertices. -Center is located where perpendicular bisectors of each of three sides intersect -Radius is distance from this point to any one of three vertices.
What three properties make up the spatial reference of a geodataset?
-A coordinate system that consists of a map projection and datum -XY resolution and, optionally, M and Z resolution and domain -XY tolerances and, optionally, M and Z tolerances
What are the types of RASTER formats?
-BIL (Band Interleaved by Line) -BIP (Band Interleaved by Pixel) -DEM (Digital Elevation Model) -GEO-TIFF -GIF (Graphic Interchange Format) -JPEG (Joint Photograph Experts Group) -RS Landsat -Standard -TIFF (Tagged Image File Formats)
What are the responsibilities of a Database Administrator?
-Backup and data recovery -Configuration -Database design -ETL functions -Installation -Migration -Performance monitoring -Capacity planning -Security -Troubleshooting
What are the five primary design principles for cartography?
-Balance -Figure-ground organization -Hierarchical organization -Legibility -Visual contrast
What is BIP or BIL?
-Band Interleaved by Pixel or Band Interleaved by Line - good at storing different brightness levels
Demers's three categories of Spatial and GIS models?
-Based on purpose -Based on methodology -Based on logic
What are non-metric categories of quantitative data?
-Binary -Nominal -Ordinal
What is the BLOBs field type?
-Binary Large Objects -Binary data stored as single entity in DBMS - Typically images, multimedia, bits of code - ArcGIS stores annotation and dimensions as BLOBs
What are some ways to be aware of where GIS is heading?
-Blogs -Conferences -LinkedIn profiles of similar GIS professionals -Local and online GIS groups -Reddit -Review job postings for skills required -Webinars
What are the two common procedures for MCE?
-Boolean overlay -Weighted linear combination
What is the NGDA Governmental Units and Administrative and Statistical Boundaries Theme?
-Boundaries that delineate geographic areas for uses such as governance and the general provision of services -Does not include boundaries associated solely with natural resources and/or cultural entities
What are the methods of spatial selection involving TOUCHING/CROSSING?
-Boundary Touches - features will be selected if they have a boundary that touches a selecting features (must be completely inside or outside the polygon) -Crossed by the Outline of - Input features will be selected if they are crossed by outline of a selecting feature -Share a Line Segment With - features selected if they share a line segment
What are four examples of discrete data?
-Buildings -Lake -Land parcels -Roads
What are some basic trends in geospatial technology?
-COMPUTING CAPACITY for Research, Apps -EXPANDING Wireless and Web NETWORKS -REAL TIME Data -MINIATURIZATION of Technology -MOBILE Geospatial Sensor PLATFORMS
What four major networks does the NSRS maintain?
-CORS (supports 3D positioning activities -permanently marked points (for survey reference) -accurate national shoreline -set of accurate models geophysical processes that affect spatial measurements.
What is the DATES field type?
-Calendar date and sometimes a time is associated
Polygon Contiguity Edges and Corners [First Order] (spatial conceptualization)
-Can only be used on polygon feature classes -Polygons that share a boundary (an edge) or a corner (a node) with the target feature influence the calculation -If polygons don't share an edge or a corner with the target feature, they are not included in the computation
Polygon Contiguity Edges Only [First Order] (spatial conceptualization)
-Can only be used on polygon feature classes -Polygons that share a boundary (an edge) with the target feature influence the calculation -If polygons don't share an edge with the target feature, they are not included in the computation
What is CPT?
-Capacity Planning Tool - developed as a framework to promote successful GIS system design and implementation
Bolstad's three categories of Spatial and GIS models?
-Cartographic models -Spatiotemporal models -Network models
What are the four major dimensions of scale?
-Cartographic scale -Measurement scale (resolution) -Observational scale -Operational scale
What disciplines are associated with Geomatics?
-Cartography -Earth mapping -Geography -Geophysics -GPS -Land surveying -Photogrammetry -Remote Sensing
Ordinal data
-Categorical, statistical data type -Variables have natural, ordered categories
How is VECTORIZATION different for CONTINUOUS rasters?
-Cells need to be reclassified, essentially grouping them into discrete form. -EXAMPLE: Temperature Raster = when you group values from [-37.8 to 0] as 0 and [0 to 37.7] as 1, you are turning it into a discrete raster. From here, you can follow the steps for vectorization from a discrete raster.
What is the greatest societal impact of map computerization (more than changing the way maps are made)?
-Changed how maps can be used. -Calculations of distance, direction, and area can easily be automated in a digital mapping system (very tedious and error prone when using a paper map)
What are some errors created when formatting data for processing?
-Changes in scale -reprojections -import/export from raster to vector
What are five examples of thematic maps?
-Choropleth -Proportional Symbol -Isarithmic or Isopleth -Dot -Dasymetric
What are Enterprise Technologies?
-Database servers -Desktop clients -Map servers -Storage Area Networks -Web servers -Windows terminal servers
What field format can temporal data time values be stored in?
-Date -Numeric -String
What are the classifications of quantitative data?
-Defined -Equal -Geometrical -Manual -Natural Breaks -Quantile -Standard Deviation
What are examples of invalid geometry?
-Degenerate or corrupt geometries Duplicate consecutive points -Vertices with missing normals. -Null geometries -Non-planar surfaces -Self-intersections -Invalid solid boundaries -Invalid solid voids -Associated texture coordinates
What are examples of interpolation tools (in ArcGIS) that are used to create surfaces?
-Density -Geostatistical -Inverse Distance Weighted (IDW) -Natural Neighbor -Spline -TIN -Topo to Raster -Trend
How is Demers's "Based on purpose" category broken down?
-Descriptive -Prescriptive
How are descriptive statistics distinguished from inferential statistics (or inductive statistics)?
-Descriptive: summarize a sample -Inferential (inductive): use data to learn about population that sample is thought to represent.
What are the common kinds of GIS platforms?
-Desktop -Enterprise GIS -Hosted (cloud) -Server
What is the National Spatial Data Infrastructure?
-Develop Capabilities for National Shared Services -Ensure Accountability and Effective Development and Management of Federal Geospatial Resources -Convene Leadership of the National Geospatial Community
Voronoi Diagram
-Diagram used to divide a plane filled with unique nodes into separate regions. -Any point within a region, you are closer to the node they contain than any other node -At any point along the region's boundaries, you are equidistant to at least two nodes. -Because of these characteristics, they're very useful for mapping and zoning
What are the limitations of dot maps?
-Difficulty of counting large numbers of dots in order to get a precise value -Need to have a large amount of initial information before drawing the map.
What are the two types / manners in which the phenomenon moves with progressively varying continuous surface data?
-Diffusion -Inherent characteristics of the moving item (mode of locomotion)
What is a DEM?
-Digital Elevation Model - e.g. 30 meter elevation data 1:24,000 7.5 minute quadrangle maps -e.g. 1:250,000 3 arc second digital terrain data
What is DXF (vector format)?
-Digital Exchange Format (DXF) -AutoCAD -no topology but lots of details
What is DGL (vector format)?
-Digital Line Graph -distributed by government -most GIS packages will import but extra manipulation needed
What might surface sample values be based on?
-Direct Measurement *e.g. height values for an elevation surface *e.g. temperature values for a temperature surface -Mathematical derivation from other data *e.g.slope derived from elevation surface
Vertex normal
-Directional vector associated with a vertex -Replacement to the true geometric normal of the surface
What are metric categories of quantitative data?
-Discrete -Continuous
What is the difference between a DISCRETE RASTER and a CONTINUOUS RASTER?
-Discrete rasters: categorical and have distinct values identifying each cell (e.g. land use) -Continuous rasters: are grid cells with gradual changing data such as elevation, temperature or an aerial photograph.
GSD - Ground Sample Distance
-Distance between pixel centers measured on ground. -E.g., in image with a 1 m GSD, adjacent pixels' image locations are 1 meter apart on the ground -For scanned images, depends on the scanning resolution and scale of original photography
What is the QUANTILE method of Quantitative Thresholding?
-Divides attribute values equally into predefined number of classes. -Attribute values are added up, then divided into predetermined number of classes. -Take number of total observations and divide that by number of classes -Result is number of observations in each class.
Universal Polar Stereographic (UPS) grid system
-Divides polar area into a series of 100,000-meter squares -Similar to UTM grid system
GIS&T Body of Knowledge
-Documents the domain of geographic information science and associated technologies (GIS&T) -First published in 2006 (DiBiase) -Digital version launched in 2016 -Maintained by UCGIS
What are the basics of the OBLIGATIONS TO COLLEAGUES AND THE PROFESSION in the GISCI Rules of Conduct for Certified GISPs?
-Don't ask others professionals to do anything fraudulent, illegal, or unethical -Don't lie about them doing something unethical -Don't retaliate against whistleblower -Don't slander them or lie about their credentials -Don't steal their work (Honor intellectual property rights)
What are the different kinds of Security testing?
-Dynamic testing -Interactive testing -Mobile testing -Static testing
Continuous data
-Each location is measure of concentration level or its relationship from a fixed point or emitting source. -Numerical data values that can be MEASURED -Transition between values non-abrupt (poorly-defined breaks)
What are two examples of continuous data?
-Elevation -Temperature
What are some applications of temporal GIS?
-Epidemiology -Disaster management -Environmental science -Transportation
What are the most commonly known types of GIS software?
-Esri (ArcMap, ArcGIS Pro) -GRASS -MapInfo -QGIS -Smallworld
How are points viewed in a 2D map?
-Every point is viewed from directly overhead, down the Z axis along parallel projection lines. -viewpoint is at infinity
What is XML?
-Extensible Markup Language -flexible and readable by humans and computers -can be shared on internet, intranets and elsewhere
What are the steps of ETL?
-Extract data from current source -Transform the data into the current format -Load the data into the final storage point
Describe the trend of Expanding Wireless and Web Networks
-Faster and broader wireless and web networks -improving data transmission, distribution, and sharing
What does FIPS stand for?
-Federal Information Processing Standard -computer system standards developed by NIST for use by non-military U.S. government agencies and contractors
What is FTP?
-File Transfer Protocol -standard network protocol -transfer files between client and server
What is .gdb?
-File geodatabase -Stored as folders in a file system. -Each dataset is held as a file
What is the FLOAT field type?
-Floating-point numbers -Single-precision
What are two examples of progressively varying continuous surface data?
-Fluid movement -Air movement
What are the four classes of map algebra transformations?
-Focal -Global -Local -Zonal
What are the four data collection types?
-GPS -Ground survey -Inspection -Remote Sensing
What is a ATMOSPHERE GPS error?
-GPS signals can experience delays when traveling through the atmosphere - Common atmospheric conditions can affect GPS signals such as tropospheric delays and ionospheric delays
What are the five necessary items to know about data's coordinate system?
-Geographic coordinate system (Datum) -Unit of measure -Zone (for UTM or State Plane) -Projection -Projection parameters (not always required)
What is the Difference Between Geomatics and GIS?
-Geomatics: focused on products, services, and tools for collection, integration, and management of geographic data. -GIS: puts data collection, storage, analysis and visualization into action.
When would you use geometric vs more complex symbols in cartography?
-Geometric symbols are easier to read at smaller sizes. -More complex symbols need more space for legibility
What is the NGDA Imagery Theme?
-Georeferenced images of the Earth's surface -Includes imagery such as Landsat, National Agriculture Imagery Program (NAIP), Digital Orthophoto Quarter Quadrangles (DOQQs)
What is GDAL?
-Geospatial Data Abstraction Library -computer software library for reading and writing raster and vector geospatial data format
What are the disadvantages of CHLOROPETH maps?
-Give a false impression of abrupt change at boundaries -Often not suitable for showing total values. -Can be difficult to distinguish between different shades. -Variations within map units are hidden (so smaller units are better than large ones).
What is a GIF?
-Graphic Interchange Format -For sharp edges and few gradations of color
At what point did HTML stop being an SGML-based language?
-HTML 5 -Browsers cannot parse as SGML for compatibility reasons.
What is System Infrastructure?
-Hardware, software, and communication network -Required information products -Spatial and non-spatial data -Spatial analysis, display, and reporting functions -Required data management resources -Anticipated number of end users
What is an example of diffusion type of movement?
-Heat from a forest fire
Why is figure-ground organization important in cartography, and what's an example of how to achieve it?
-Helps readers focus on a specific area of the map. -Can use a whitewash, a drop shadow, or feathering.
What are the three basic methods of Spatial Selection?
-Identical To - features are identical to input layer -Intersect -Within a distance
What are the main Vector Overlay Tools?
-Identity -Intersect -Symmetrical Difference -Union -Update
Which Vector Overlay Tools can use any input data type?
-Identity -Intersect -Update
Which Vector Overlay Tools are used for binary overlay?
-Identity -Symmetrical Difference -Update
Which Vector Overlay Tools must use polygons as overlay data?
-Identity -Symmetrical Difference -Update
When (and why) are TINs usually used to represent a surface?
-In engineering applications -Spot heights can be irregularly distributed to accommodate areas of high variability in the surface -Spot heights' values and exact positions are retained as nodes in the TIN.
How is Demers's "Based on logic" category broken down?
-Inductive -Deductive
What are the disadvantages to using RASTERS?
-Inefficient (very large) for storage -Compression techniques not efficient with variable data -Large cells could cause information loss -Poor at representing points, lines, areas -Each cell can be owned by only one feature -Must include redundant or missing data
What is the IMPLEMENTATION PHASE of systems architecture design?
-Initial deployment and operational testing -Final system delivery -User training -System maintenance operations
Canadian Geographic System (CGIS)
-Initiated by Roger Tomlinson -Many consider CGIS as the roots of Geographic Information Systems
Covers (topological relation)
-Interior of Object B is completely inside Object A and their boundaries intersect -this is the opposite way of saying the same thing as "covered by" i.e. If Object A covers Object B, then Object B is covered by Object A aο ∩ b = b
Covered By (topological relation)
-Interior of Object B is completely inside Object A and their boundaries intersect -this is the opposite way of saying the same thing as "covered by" i.e. If Object B is covered by Object A, then Object A covers Object B. Covers(b,a)
Which Vector Overlay Tools are used for multiple layer overlay?
-Intersect -Union
What are the four types of values by which most discrete data are represented?
-Interval -Nominal -Ordinal -Ratio
What are the three kinds of inverse distance spatial conceptualization?
-Inverse Euclidean -Inverse Manhattan -Inverse Distance squared
What are the steps to checking data values?
-Is the data type correct for this field? -Is the value within the valid range? -Check for duplicates (e.g. of a unique key). -Check for nulls. -Are there mandatory values, or are nulls allowed?
What is a JPEG?
-Joint Photograph Experts Group -Variable-resolution compression system -Both partial and full resolution recovery
What is a PSB file?
-Large document formatof a PSD -all attributes of PSD plus the added capability of supporting file sizes larger than pixel limit of PSD
What is LiDAR?
-Light Detection and Ranging. -similar to RADAR but uses laser pulses instead of radio waves -measures distance by illuminating a target with a laser and analyzing the reflected light
What are the two forms of ISARITHMIC (aka ISOPLETH) map
-Lines of equal value are drawn such that all values on one side are higher than the "isoline" value and all values on the other side are lower -Ranges of similar value are filled with similar colors or patterns.
Equidistant projection
-Maintains distance but distorts other properties
What is Application security and why is it important?
-Making applications more secure by finding, fixing, and enhancing the security
Canadian Land Inventory (CLI)
-Managed soil, drainage and climate characteristics on the Canadian landscape. -Determined land capability for crop types and forested areas, so it became a key decision-making tool for land use in Canada
Equidistant Projection
-Map projection -Represents areas in correct relative size
What are some general best practices of repairing and reporting bad data?
-Map the schema to fit the destination data model. -Geometry manipulation (e.g. snap dangling lines closed, clip crossing lines, fill in slivers) -Enforce compliance with your company's standards. (e.g. remove duplicate features, filter out wrong kind of geometry) -Simply flag bad data and return for human analysis.
What are the steps of the report that should be performed after a validation check?
-Measure and describe the quality of the data in a standardized way, e.g. data download or PDF. -Send the report via email, SMS, form, etc.
Interval data
-Measured along a scale -Each point is equal and standardized distance from others -Always numbers or numerical values
What are the core components of a metadata record?
-Metadata Record Information -Identification Information -Constraints Information -Data Quality Information
What is the most important decision factor when trying to ensure legibility of your map?
-Selecting symbols -familiar and appropriately sized
What is one of the major objectives in map-making?
-Separate meaningful characteristics -Portray likenesses, differences, and interrelationships
What is a commonly used tactic to see how areas change over time on a single static map?
-Shading and coloring e.g. original range designated by one color, with the new range overlaid in another color. -On black and white maps, shading or cross-hatching can be used instead of color.
What is the general rule of thumb about feature positioning in map-making?
-Should match the map's intent. -e.g. if map is designed for visitors to navigate a park, walking paths and locations of interest should stand out and be labeled or properly symbolized
What are the two TYPES of Relationship class properties?
-Simple -Composite
As a rule of thumb, should items in the legend of a map be in the singular or plural format?
-Singular
Describe the trend of Mobile Geospatial Sensor Platforms
-Small devices (e.g. smallsats, drones) -Quickly designed and deployed -Tailored to mission. -Expand the abilities of everyone to collect more data
How is software related to hardware?
-Software runs on a variety of hardware types -Software may rely on DBMS type, OS type
What are some examples of features that fall along a continuum between discrete and continuous data?
-Soil types -Edges of forests -Boundaries of wetlands -Geographic markets influenced by a television advertising campaign.
Metadata (source of discrepancy)
-Sometimes metadata is not updated according to the original features. E.g.features are edited but the edited information is not updated (name of the editor, reason for editing, etc). --Metadata must be updated with the original data.
Data Transfer (source of discrepancy)
-Sometimes, to make less accurate data more accurate, user tries to apply different advanced rectification technique but as a result the less accurate data changes into highly degraded data. "There is no bad or good data. There are only data which are suitable for a specific purpose."
Four primary types of "resolution" for rasters
-Spatial -Spectral -Temporal -Radiometric
What are the three resolutions in remote sensing?
-Spatial -Spectral (electromagnetic spectrum measured) -Temporal
What is the preferred standard for geospatial data transfer?
-Spatial Data Transfer Standard (SDTS) FIPS 173 -Robust way of transferring GIS data between computers with no information loss, including metadata
What are the 3 types of RASTER RESOLUTION?
-Spatial Resolution -Spectral resolution -Temporal resolution
What is spatio-temporal data?
-Spatial data that changes across time -Describes a phenomenon in a certain location *and* time -e.g. shipping movements across a geographic area over time
What is a Profile map?
-Special case of a 2D plan map -Viewer looks horizontally along X or Y axis (not vertically down Z axis) -Used to produce ground-level silhouettes of landscape.
What is SGML?
-Standard Generalized Markup Language -Standard for defining generalized markup languages for documents
What is the basic process of VECTORIZATION (DISCRETE raster to vector)?
-Start with a discrete raster -Find appropriate the Vectorize (Raster to Vector) tool - -Select output of the raster to a point, line or polygon. -Run tool -All necessary vertices and paths will be created showing, for example, building outlines.
What is the basic process of RASTORIZATION?
-Start with a vector (e.g. simple line with a vertex at start and end). -Find appropriate the Rasterize (Vector to Raster) tool . -Determine output pixel size (set horizontal and vertical parameters). -Run tool. -Output will look like gridded version of vector.
How is Demers's "Based on methodology" category broken down?
-Stochastic -Deterministic
What is a PROCEDURE (in context of database object relationships)?
-Subroutine -Available to applications that access a relational database system (data validation, access control mechanisms)
What does the ZONAL STATISTICS Raster Overlay Tool do?
-Summarizes values in a raster layer by zones (categories) in another layer -e.g. calculate the mean elevation for each vegetation category
In ArcGIS, what are Representations?
-Symbol information where feature geometry stored inside feature classes. -Property of a feature class -Feature class can have more than one representation associated with it -Collection of rules to define how each category of feature should be displayed
Which Vector Overlay Tools must use polygons as input data?
-Symmetrical Difference -Union
Maximum z-tolerance
-TIN construction algorithm -ensures difference between original elevation point's elevation and estimated elevation from the TIN is within specified tolerance
What is a TIFF?
-Tagged Image File Formats - associated with scanners
K Nearest Neighbor (spatial conceptualization)
-Target feature is analyzed relative to a fixed number (k) of its closest neighbors
What is a .txt file?
-Text file -unformatted ASCII text -can be saved as .txt documents in small file sizes.
Kriging
-Tool in 3D analyst -Multistep process 1. Exploratory statistical analysis of data 2. Variogram modeling 3. Creating surface 4. (optionally) exploring a variance surface. -Most appropriate when you know there is a spatially correlated distance or directional bias in the data.
What is the final Communication Packet interval?
-Transferred from the host to receiver
What is TIN?
-Triangulated irregular network -nets of triangular facets defined by nodes and edges that cover a surface
Disjoint (topological relation)
-Two objects have no common point together -they form a set of disconnected geometries a ꓵ b = Θ
Intersect (topological relation)
-Two objects' boundaries and interior touch in at least one place or "Overlap" a ꓵ b ≠ Θ
Touches (topological relation)
-Two objects' boundaries share at least one common point, but their interiors do not -aka "Meet" (a ∩ b ≠ ∅) ∧ (aο ∩ bο = ∅)
What are some examples of typical topology errors?
-Unmatched intersections -Unsnapped lines -Duplicate elements
What is the best way to symbolize features when using the Standard Deviation method of Quantitative Thresholding?
-Use a diverging color scheme will emphasize which observations are above and below the mean
Dot map
-Uses uniform point symbols to show partial data, with each symbol representing a unit value -Create a visual impression of density by placing a dot or some other symbol in the approximate location of the variable being mapped.
What is HIERARCHICAL ORGANIZATION as it relates to the primary design principles for cartography?
-Visual layering of information by importance -Helps focus on important data and identify patterns
When would you use the Inverse Euclidean Inverse Distance spatial conceptualization?
-When modeling continuous data -e.g. temperatures changes
When would you use the Inverse Manhattan Inverse Distance spatial conceptualization?
-When modeling fixed urban point features (like grocery stores) and you dont have a road network.
Weighted Linear Combination (MCE)
-When more than one attribute needs to be considered to find the most suitable location, each is assigned a weight based on its importance. -Multi-attribute spatial features with final scores result. -The higher the score, the more suitable the area.
When would you use the Inverse Distance Squared spatial conceptualization?
-When you want only the neighbors closest to the target features to exert significant influence on it (this is because the slope is sharper, and influence of features on the target feature drops off more quickly)
What are the methods of spatial selection involving WITHIN?
-Within - features will be selected if inside a selecting polygon -Completely within - features will be selected if completely within selecting polygon (no overlap) -Within Clementini - features will be selected and cannot be entirely on the boundary of the features -Have their Center In - Features will be selected if their center falls within a selecting feature
What are the main Raster Overlay Tools?
-Zonal Statistics -Combine - Single Output Map Algebra - Weighted Overlay -Weighted Sum
What is the defining feature of an oblique/3D perspective?
-a fixed viewpoint -perspective view with converging projection lines.
What is the difference between a spheroid and a datum?
-a spheroid approximates the shape of the earth -a datum defines the position of the spheroid relative to the center of the earth
How does Kriging fit into the context of surface development?
-advanced technique -most useful when there is a spatially correlated distance or directional bias in the data. -most used in soil science and geology.
From which sources can temporal variation arise in cartography?
-agents (?) -data -designer -intrinsic relationship between map elements -observer -software
What is the SERVER GIS platform?
-allows access to web GIS -control of GIS data on your own infrastructure -control over how GIS platform is deployed, maintained, secured, and used
How is temporal GIS applied in the field of epidemiology?
-analyze disease outbreak and distribution -1854, John Snow study where outbreak of cholera in London was traced to a contaminated water pump
What are some reasons why temporal data is collected?
-analyze weather patterns -analyze environmental variables -monitor traffic conditions -study demographic trends
Describe DYNAMIC SECURITY TESTING
-analyzes running code -can simulate an attack
What are longitude and latitude?
-angles measured from the earth's center to a point on the earth's surface. -often are measured in degrees (or in grads).
What Are Markup Languages?
-annotate text -annotations invisible to the end-user. -computer/browser reads annotations before processing -presents text as instructed by markup commands.
What are coordinate systems?
-arbitrary designations for spatial data -provide a common basis for communication about a particular place or area on the earth's surface
What kind of features can be created as a Coverage file?
-arc -node -point -polygon -region -route -route system -section
What is the EQUAL INTERVAL method of Quantitative Thresholding?
-arranges into groups containing equal range of values. -take range of data (maximum - minimum) and divide by chosen number of categories.
What is a commonly used tactic to illustrate motion over time?
-arrows or lines showing direction of movement -dots show origin point, end point, and significant stops in between -all dots labeled with dates (e.g. useful when plotting the migration of a group)
What is a CODED VALUE DOMAIN (in context of database object relationships)?
-attribute domain -defines a set of permissible values for an attribute in a geodatabase -has a code and its equivalent value
What are EXPLICIT REPORTS (in terms of measurement)?
-beliefs people express about things -e.g. survey
What is TIGER (vector format)?
-block level maps of every village, town, and city in US
Define collectively exhaustive in the context of classification
-categories "exhaust" or include all individuals (ideally) -an individual cannot belong to zero categories
What are some format-specific QA/QC items for databases?
-check the data and geometry before attempting to load it into a central repository.
What are the benefits of the QUANTILE method of Quantitative Thresholding?
-classes are easy to compute -each class is equally represented on the map. -ordinal data can be easily classified b/c the class assignment of quantiles is based on ranked data
What is the DEVOPS application development method?
-collaboration between differennt departments of development life cycle *Development *Quality Assurance *Operations
What is an ELSE STATEMENT?
-combined with an if statement -if that statement is false, defaults to the else condition
What is the Parallel Oblique projection?
-compressed derivative of the Plan Oblique -disadvantage: less useful for measuring distances than Plan Oblique -advantage: works better at larger map scales and looks more realistic.
Geographic Information System (GIS)
-computer-based tool used to help people transform geographic data into geographic information. -decision support tool (David Cowen, 1988)
How is elevation indicated in a 2D map?
-contour lines
What are some commonly-used techniques to indicate elevation in a 2D map?
-contour lines -hillshading -hypsometric color. -spot heights
What four things does an ArcGIS spatial reference includes settings for?
-coordinate system -coordinate precision (aka coordinate resolution) -processing tolerances (e.g. cluster tolerance) -spatial or map extent covered by dataset (aka spatial domain)
What is Virtualization?
-creation of a virtual machine that acts like a real computer with an operating system
.dbf
-dBASE table -the structured data / table format in a shapefile
What is the NGDA Geology Theme?
-data pertaining to the origin, history, composition, structure, features, and processes of the solid Earth, both onshore and offshore. -includes geologic, geophysical, and geochemical maps, stratigraphy, paleontology, geochronology, mineral and energy resources, earthquakes, volcanic eruptions, coastal erosion, and landslides. -does not include soils.
What is the NGDA Address Theme?
-data that specify a fixed geographic location by reference to a thoroughfare, landmark, or point of postal delivery
Data Information Exchange (source of discrepancy)
-information about data provided by client -degree of information provided by client defines accuracy and completeness of data.
What is Constraints Information (in metadata)?
-information about legal and security limitations to data access and use.
What is INSPIRE?
-infrastructure for spatial information in Europe. -provides a policy framework and timetable for sharing spatial data within the EU in a multinational, multiagency spatial data infrastructure
What is the ENTERPRISE GIS platform?
-integrated through entire organization -large number of users can manage, share, and use spatial data and related information
How does Trend interpolation work (surface development)?
-interpolate sample points using least-squares method -good for identifying coarse scale patterns
How does Spline interpolation work (surface development)?
-interpolate sample points using polynomial method -minimizes sharp bending -useful for smoothly-varying surfaces (e.g. water table heights.)
What is Syntactic translation?
-involves converting specific digital symbols (letters and numbers) between systems.
Why is resolution a fundamental concept in GIS?
-it affects the reliability of a study -it contributes to uncertainties of findings / conclusions
What is the basic purpose of a datum?
-it links a spheroid to a particular portion of the earth's surface. -defines origin and orientation of lat/long lines -recent datums are designed to fit the entire earth's surface well (geocentric datums)
Why are 3D/oblique projections problematic for some applications?
-large variation in direction and distance. -focus is on center view (peripheral areas distorted). -significant areas may be hidden from view
One which two items is the impact of cartographic representations often based?
-legends -scales
What is an example of the TRANSFORM aspect of the ETL methodology?
-making all attribute tables uniform if there are multiple shapefiles of same type of data and they have different attribute tables.
Steinhaus Paradox
-measured length increases with increasing accuracy -detail becomes apparent at a predictable rate
How is temporal GIS applied in the field of disaster management?
-mitigation and the development of recovery strategies -e.g. evaluating historical data for patterns that may help to evaluate future risk of events
What is COMPUTATIONAL MODELING (in terms of measurement)?
-models as simplified representations of reality
What is an EXPRESSION (in the context of Scripting)?
-most basic programming instruction *Contain values and operators that can reduce to a single value
Why is it recommended that you store the time values of your temporal data in a date field?
-most efficient format for query performance -supports more sophisticated database queries than numeric or string field.
What is the one of the most basic questions asked of a GIS?
"what's on top of what?" e.g. What landuse is on top of what soil type? e.g. What parcels are within the 100-year floodplain? e.g. What roads are within what counties?
DE-9IM
(Digitally Extended 9-Intersection Model) Topological model created by Egenhofer -It is the standard used to describe the spatial relations of two geometries -Used as the basis for standards of Queries and Assertions
Type and Source (source of discrepancy)
-must be evaluated in order to get appropriate data values. -all formats have pros and cons. -E.g.Topology cannot be created on shapefiles-only in geodatabase. So, data type and source must be identified and evaluated before proceeding towards any analysis.
What is the NGDA Land Use - Land Cover Theme?
-natural and man-made surface features that cover the land (Land Cover) -primary ways in which land cover is used by humans (Land Use)
Spatial Data Types
-needed to model geometry and to represent geometric data in database systems
Define mutually exclusive in the context of classification
-no overlap between any two categories (ideally) -individual cannot belong to two categories simultaneously
Describe Quantitative Data
-numerical values -measured on at least an ordinal level but could be on a metric level
What is a GEODATABASE?
-object-oriented data model -represents features and attributes as objects
Describe Observation of Behavior (in terms of measurement)?
-observable actions or activities of individuals or groups -NOT thoughts, feelings or motivations
What is OBSERVATION OF BEHAVIOR (in terms of measurement)?
-observable activities or actions -NOT thoughts, feelings, motivations
Describe PREPARATION as it relates to data collection workflow
-obtaining data -redrafting poor-quality map sources -editing scanned map images -removing noise -setting up appropriate GIS hardware and software systems to accept data
What is the GRASS GIS software?
-open source GIS software developed by US Army Corps of Engineers
What are SEQUENCES (in context of database object relationships)?
-ordered collection of objects -repetitions are allowed (finite or infinite) -number of elements is length of sequence
What is Big data management?
-organization, administration and governance of large volumes of both structured and unstructured data. goal: ensure high level of data quality and accessibility for business intelligence and big data analytics applications.
Describe SPECTRAL RASTER RESOLUTION
-parts of electromagnetic spectrum that are measured
What is a Data Collection Rate (sync rate)?
-point data: 1-second interval -polygon and line data: 5-second interval
Describe EVALUATION as it relates to data collection workflow
-process of identifying project successes and failures
How does Density interpolation work (surface development)?
-produce a surface that represents how much or how many of some thing there are per unit area.
What are Relationship class properties?
-properties that define how objects in the origin relate to objects in the destination. -specified when relationship class is created
What is the GEOMETRIC INTERVAL method of Quantitative Thresholding?
-used for visualizing continuous data that is not distributed normally. -designed to work on data that contains excessive duplicate values, e.g., 35% of the features have the same value.
What are Summary Statistics?
-used to summarize set of observations -communicate largest amount of information as simply as possible -e.g. arithmetic mean -e.g. standard mean absolute deviation -e.g. correlation coefficient
What are GROUPS in the context of database management?
-users granted access based on common functions.
Describe the basics of a geographic coordinate system
-uses spheroid to define locations -includes: *angular unit of measure *prime meridian *datum (based on a spheroid) -point is referenced by its lat/long values
Describe EDITING AND IMPROVEMENT as it relates to data collection workflow
-validate data -correct errors -improve quality
What are some format-specific QA/QC items for XML / JSON data?
-validate the syntax or schema.
What is a SHAPEFILE?
-vector data format that stores location, shape, and attributes
What is a .img file?
-vector graphics file -similar to Computer Graphics Metafile (.cgm)
How does the Natural Neighbor interpolation work (surface development)?
-very similar to IDW interpolation -difference is that data points used to interpolate surface values are identified and weighted using a Delauney triangulation (like with TIN) -reliably works with much larger datasets than the other interpolation methods.
When would a Coefficient of Determination outside the range 0 to 1 occur?
-when model fits data worse than a horizontal hyperplane. -e.g. when wrong model was chosen -e.g. nonsensical constraints were applied by mistake.
What defines a coordinate system?
-whether it's geographic or projected -unit of measurement (usually feet or meters) -definition of map projection (projected systems only) -spheroid* -datum* -standard parallels* *depends on system
How do ZONAL OPERATIONS work in the context of map algebra transformations?
-work on areas of cells that share same value - computing a value based on cells in a particular zone e.g. a watershed
How do FOCAL OPERATIONS work in the context of map algebra transformations?
-work on cells and their neighbors - calculates a value based on all neighboring cells -e.g. find average of all cells around a certain cell
How do LOCAL OPERATIONS work in the context of map algebra transformations?
-work on individual pixels -combine rasters that overlay each other -e.g. add/subtract/etc. cells that are in same location
How do GLOBAL OPERATIONS work in the context of map algebra transformations?
-work on the entire layer - apply a formula to all cells -e.g. Add/subtract/multiply/etc. all cells based on one value -e.g. Find the distance from one cell to all cells
Because there is a significant amount of GIS data being created and modified on constant basis...
...following procedures to manage, document, and communicate this work is extremely important.
What are the three file types that are REQUIRED for a SHAPEFILE to work?
.dbf .shp .shx
What file extensions can a Raster have?
.jpg .tif .gif
What are the file types that can make up a SHAPEFILE?
.shp .shx .dbf - attribute information .prj - projection format .sbn .sbx .shp.xml
Degree of Applicability
0-100% scale measuring how strongly a spatial relation holds
How many KB is 1 MB?
1,000 KB
How many MB is 1 GB?
1,000 MB
What are the three constructs solely pertaining to the transfer media?
1. Application Programming Interface (API) 2. File based transfer 3. Web services
What are the two basic, simplified steps of data validation?
1. Check that it fulfills requirements 2. Repair it where it doesn't pass
What is the term Data Transformation usually referring to?
1. Converting from one coordinate system to another 2. Moving from one data structure to another data structure (e.g. aggregating road data may require attributes to be converted to a standard type ([e.g. road type])
What are the NGDA Themes?
Address Biodiversity and Ecosystems Cadastre Climate and Weather Cultural Resources Elevation Geodetic Control Geology Governmental Units and Administrative and Statistical Boundaries Imagery Land Use - Land Cover Real Property Soils Transportation Utilities Water - Inland Water - Oceans & Coasts
APFO
Aerial Photography Field Office (division of USDA)
What do all operations that involve combining multiple data files rely on?
All files must contain a common key, which allows the database system to relate the separate files to each other
What is the output of the UNION tool in the context of Vector Overlay Tools?
All input features
What is AAG?
American Association of Geographers
ASCII
American Standard Code for Information Interchange -character encoding standard for electronic communications e.g. "A" = 065 in ASCII or 01000001 in binary
Spatial Analysis (simplest definition)
An analysis (study) of shapes in space
Parallels
Another name for lines of latitude
How did GIS originate (broadly)?
Arose out of the need to perform spatial queries on geographic data.
How can lines where the shape of the surface abruptly changes (e.g. ridge-lines, streams, or roads) be incorporated into TINs?
As breaklines
How can areas that share a value be incorporated into TINs?
As fill polygons
Error
Assessing both the imprecision of data and its inaccuracies
What is georeferencing?
Associating a map (eg pdf or jpg without spatial information) or image (e.g. aerial image without spatial information) with spatial locations
Metadata question: How are the data _____________ defined?
Attributes
What is .dgn?
AutoCAD and Microstation files
What was the original, most basic motivation for developing computer mapping systems?
Automate the map making process.
Describe Ground Survey as a data collection type
Based on principle that 3D location of any point can be determined by measuring angles and distances from other known points
Why do I need to know what DBMS are?
Basic database concepts are important since GIS incorporates much of the functionality of database management systems (DBMS)
Why is uncertainty an unavoidable part of spatial data?
Because the data is an approximation of real-world phenomena.
What is the fourth step in the field collection process?
Begin field collection on a good representation of the entire dataset
What is a large part of the mission of UCGIS?
Being a steward of the GIS&T Body of Knowledge
How can most automated data collection be completed?
By writing scripts
What is the basic premise of data collection automation?
Data is automatically updated or appended and instantly converted into a useable format
What is temporal data?
Data that represents a state in time e.g. land-use patterns of Hong Kong in 1990
What is a DBA?
Database Administrator
DBMS
Database Management Systems
Relational database management systems
Database systems that enable users to produce information from relational databases (ex?)
Relational databases
Databases that contain numerous files that share one or more keys (simple ex?)
What is a topologically valid dataset?
Dataset in which topological rules are enforced (ex. coverage data model; ex of opposite = shapefile) - can trust the accuracy of the data more
What word is used interchangeably with "geographic coordinate system"?
Datum
Even if using the same map projection and projection parameters, what will cause coordinates for a location to change?
Datum and spheroid on which coordinates are based
How greatly do Spatial Data Types affect performance of Spatial Database Systems?
Decisively affect performance of Spatial Database Systems
Topological Rules
Define how vector objects are stored and interact with each other
XY Tolerance
Defines the minimum allowable distance between vertices before they are considered equal
Semivariance
Degree of distance between points on a surface
Will RASTORIZATION always work right on the first run?
Depending on pixel size you set, may have to do trial-and-error for better results
Spatial Modeling
Describes basic properties and processes for a set of spatial features
What is geospatial metadata specifically?
Describes maps, GIS files, imagery, and other location-based data resources
What are some best practices for workflow-based data validation?
Detect differences in an updated version of the same data. -Validate submitted data immediately to stop bad data from being processed. -Check that submitted package contains required files and formats -Perform a schema check and a data-level check
Viewshed
Determination of what can be seen from a set of target viewpoints
What is the third step in the field collection process?
Determine how it will be collected e.g. pen and paper, mobile tablet, drone
What is the first step in the field collection process?
Determine the result of field work
What is the second step in the field collection process?
Determine what needs to be collected, inspected, or surveyed (and set up a field collection form)
International Organization for Standardization (ISO)
Develop and publish International Standards
What is a commonly used tactic to see how an area's borders have changed over time on a single static map?
Different line weights representing "before" and "after" will visually distinguish between them
Data accuracy
Discrepancy between map info and real world values
What is the only type of the 9 spatial relations that has no restrictions regarding which geometries can and can't participate with each other?
Disjoint
Range
Distance on a semivariogram where the model first flattens out
What is an example of an appropriate theme for dot maps?
Distribution of dairy farms, and population distribution in a region.
Radial Basis Functions
Diverse group of spatial interpolation methods tat include thin-plated splines, thin-plated splines with tension, and regularized splines
What is the first step in rasterizing an aerial photograph?
Divide the area into grids of the same size
Who started the US GPS satellite program and why
DoD in the 1970s for military use
.dtd
Document Type Definition -Description of structure and properties of a class of XML files.
What is the basic rule for how detailed datasets should be?
Doesn't need to contain detail for unimportant aspects e.g. on weather map, not every road needs to be shown
Data Capture (source of discrepancy)
During data capture, the user may misinterpret features from the base data and capture the features with errors. -must be performed on a perfect scale where one must be able to view the features distinctly.
In a raster, why is the amount of detail that can be represented for the surface limited to the size of the pixels?
Each pixel only contains a single value
What is the difference between a tag and an element in XML?
Element contains at least three part: start-tag, end-tag, and text or more markup between. -<color>red</color> is an element -<color> is the start-tag
What are custom tags in XML called?
Element types
Why are geographic data different from non-geographic data?
Geographic data: records correspond with places *Columns represent the attributes of places. Non-geographic data: records correspond with people or accounts.
Geomatics
Geographic information: -Gathering -Storing -Processing -Delivering Geomatics university curriculum would include: -Geodesy -Land surveying -Remote sensing -Photogrammetry -Other scientific studies.
Fractals
Geometric set (points, lines, areas or volumes) where larger scale is not proportionately larger -it is larger due to more details being visible at the larger scale
What is GITA?
Geospatial Information & Technology Association
What is the GTCM?
Geospatial Technology Competency Model
What is GNSS?
Global Navigation Satellite System
How influential are Spatial Data Types on the expressiveness of SQLs
Greatly influential
What is the goal of an uncertainty analysis?
Helps define and understand the possible sources of uncertainty in the data or analysis.
What is the goal of a sensitivity analysis?
Helps relate the amount of uncertainty and its relation to input variables
What are the edges in a geographic coordinate system called?
Horizon
Spatial Relation
How an object is situated / located relative to another object (reference object)
Object-relational databases
Hybrid object database (data is stored as objects) and relational database (data is stored in tables)
What is HTML?
Hypertext Markup Language (HTML) -set of markup symbols or codes -inserted in file intended for display on browser page
What are the sections of the GISCI Rules of Conduct for Certified GISPs?
I. Obligations to Society II. Obligations to Employers and Funders III. Obligations to Colleagues and the Profession IV. Obligations to Individuals in Society
You're using Spatial Extender: what installs the Types and Functions of the Spatial Data Types?
IBM DB2
You're using Spatial Datablade: what installs the Types and Functions of the Spatial Data Types?
IBM Informix
What is the new FGDC endorsed geographic metadata standard?
ISO 19115
What is meant by: "good categories should have minimal intra-category variation and maximal inter-category variation"
Ideal categories contain things that share many characteristics with other members of the category, and have little in common with things outside the category.
What is a common everyday use of database queries?
Identify subsets of records that meet criteria established by the user (e.g. a county tax assessor may need to list all properties not assessed within the past 10 years)
What is the difference between Implementation Standards and Abstract Specification?
Implementation Standards written for more technical audience
What is the difference between ISARITHMIC (aka ISOPLETH) map and CHLOROPETH maps?
In Isopleth maps the data is not grouped to a pre-defined units like a city district.
DPI - Dots Per Inch
In remote sensing, actually used to mean PPI (Pixels Per Inch).
When and why did the concept of the cartographic spheroid begin?
In the 18th century, when people began to realize that the earth was not perfectly round.
What were (and in what decade) the first steps taken to move away from hand drawing/engraving maps?
In the 1980s, mapmakers began to adopt CAD in place of traditional map drafting.
Should Spatial Data Types be dependent on or independent from the data model used by a DBMS?
Independent
For improving time visualization and query performance, it is recommended that you do this to the fields containing the time values:
Index
What is the simplest definition of metadata?
Information about data
How can cartographic representation be defined?
Information is depicted in a way that the senses can perceive the spatial structure of the portrayal
What is the output of the UPDATE tool in the context of Vector Overlay Tools?
Input feature geometry replaced by update layer
What is the output of the IDENTITY tool in the context of Vector Overlay Tools?
Input features, split by overlay features
What is the LONG INTEGER field type?
Integer between -2,147,483,648 and 2,147,483,647
What is the SHORT INTEGER field type?
Integer between -32,768 and 32,768
What is the NGDA Water - Inland Theme?
Interior hydrologic features and characteristics, *aquifers *watersheds *wetlands *navigation *water quality / quantity *groundwater information
What type of data is best represented by varying shades or varying intensities of the same color ?
Interval and ratio data (shows quantitative differences)
Describe vertices in the context of vector development
Nodes / point locations specified by latitude and longitude coordinates -when connected by a line, they form the shape of the vector
What type of data is best represented by differing shapes, colors, textures rather than differing sizes?
Nominal data (shows qualitative differences)
What does NAD stand for?
North American Datum
How has research over the past few decades modified the paradigm of western cartography?
Now consider broader issues: how map-based displays enable creative thinking and problem solving
Geospatial Data is to Food as Metadata is to:
Nutrition Label
Who created GML?
OGC
What is another word for a 3D perspective?
Oblique
Metadata question: How does one _____________ the data?
Obtain
What is the simplest definition of data transfer?
Obtaining data from external sources
What is the output of the INTERSECT tool in the context of Vector Overlay Tools?
Only features common to all input layers
What is OGC?
Open Geospatial Consortium -International consortium: *government agencies *research organizations and universities -Goal: Make geospatial information and services FAIR: *Findable *Accessible *Interoperable *Reusable
What type of data is best represented by differing sizes of same shapes?
Ordinal and interval data (shows quantitative differences)
What is the NGDA Biodiversity and Ecosystems Theme?
Pertain to organisms and their environments.
Michel Paradis
Photogrammetrist working for the Ministry of Natural Resources in the Quebec Provincial Government -Credited for creating the term "Geomatics" or "Geomatique"
What is the 3D projection that sits on a planimetric base and addresses most of the issues found with 3D perspective maps?
Plan Oblique
What is the sixth step in the field collection process?
Plan locations and timing for field work
The main non-Esri programs that utilize spatial data types
PostGIS Spatial Extender Spatial Datablade
You're using PostGIS: what installs the Types and Functions of the Spatial Data Types?
PostGRE SQL
What is the difference between primary and secondary data?
Primary data is collected by researcher for own use. Secondary data is collected for another purpose by someone other than researcher.
What is the difference between primary and secondary data?
Primary data is collected specifically for the researchers use, while secondary data is collected for another purpose by someone other than the researcher
What are the pros and cons of the EQUAL INTERVAL method of Quantitative Thresholding?
Pro: Show different groups when they are close in size. Con: Doesn't often occur in geographic phenomena
Reverse Geocoding
Process of converting geographic coordinates into a human-readable address.
Metadata question: How were the data _____________ ?
Processed
What is Database design?
Producing a detailed data model of a database
What type of thematic map should be used to display temperature data and relief data?
Temperature and elevation exist are continuous and do not change abruptly at any point -e.g. population density may change abruptly as you cross into another census zone
Spatiotemporal
Term used to describe phenomenon, data, maps, etc., that treat both space and time together.
How should the labels for rivers be oriented on a map?
Text should curve as the river does
If the micron scan of one image is 12.5 and another is 15, which one has a higher resolution?
The 12.5 micron image
If the micron scan of one image is 12.5 and another is 15, which one will cover a larger Ground Sample Distance?
The 15 micron image
Spatial Analysis (lay explanation)
Turning a map into information by analyzing its contents—finding patterns, assessing trends, or making decisions. -what our eyes and minds do naturally whenever we look at a map
What do vectors and rasters have in common?
Two predominant strategies representing locations and extents in digital form that were developed as a way to converting graphical data stored on paper maps into digital data -Two distinct sampling strategies for digital geographic data
Intersection Operation
Type of query that produces a data file that contains only records present in both/all input files.
Difference operation
Type of query that produces a data file that eliminates records that appear in both original files.
Union Operation
Type of query wherein two or more data files are combined into a single file that includes all records and attributes, without redundancy
UCGIS
University Consortium for Geographic Information Science
Viewshed analysis
Uses a digital elevation model (DEM) to determine the visibility to (and from) a specific location.
Differential Correction
Uses data from a base station to correct noise errors in GPS data
What is a PROPORTIONAL SYMBOL map?
Uses symbols of different sizes to represent data associated with different areas or locations within map.
false northing
Value applied to the origin of a coordinate system to change the y-coordinate readings
UAS - Unmanned Aerial Systems
e.g. drones
What are the implications of using different classification styles?
each style will highlight different aspects of the trends in the dataset
David DiBiase
Wrote the online Penn State GIS textbook "The Nature of Geographic Information" and the first edition of the GIS&T Body of Knowledge (BoK)
Which coordinates can be plotted in a 2D map?
X and Y
What are some GIS-related work activities that are regulated by specific policies and procedures?
editing, storing, and archiving data
Describe digital geographic data
encoded alphanumeric symbols that represent locations and attributes of locations measured at or near Earth's surface
What are some format-specific QA/QC items for CAD data?
ensure the robust extraction of: -blocks -extended entity data -geometry -layers -line type -text
What is a MULTIPATH GPS error?
errors caused by reflected GPS signals arriving at the GPS receiver - nearby structures and other reflective surfaces
What did Executive Order 12906 do?
established executive branch leadership for development of NSDI -development of a National Geospatial Data Clearinghouse -development of spatial data standards -development of a National Digital Geospatial Data Framework and partnerships for data acquisition
Boolean overlay (MCE)
evaluating rasters with Boolean operators to evaluate areas where combinations of specific conditions exist (e.g. using intersect or union tools)
Euclidean Distance
exact distance between two coordinates [sqrt((x1‐x2)^2 + (y1+y2)^2))]
What are CONDITION STATEMENTS (in the context of Scripting)?
examples: -If -Else -Elif
Describe the INTERSECT spatial data selection function
extracts features which overlap in all layers to new feature class (joins attribute tables)
Describe the CLIP spatial data selection function
extracts input features that overlay the clip features (keeps inputs attributes)
What has been a recent change in 3D/oblique projections that has improved them?
generating them with parallel projection lines.
Is a higher or lower SNR preferable?
higher value of the SNR mask will minimize noise error
Data Precision
how exact is the description of data
Distance
how far away the object is from the reference object
What is VISUAL CONTRAST as it relates to the primary design principles for cartography?
how map features and page elements contrast with each other and their background
Interposition
if one object partially blocks our view of another, we perceive it as closer
How does ArcGIS 10 implement Map Algebra?
in Python
Horizontal and Vertical Distance
in reference to a coordinate plane with an xy axis
Database Management System (DBMS)
information system used to store, update, and analyze databases.
Why is it unlikely for authorized land uses to be included as an attribute in a community's property parcel database?
Zoning (authorized land use) and taxation (parcel database) are typically the responsibilities of different agencies.
.swm
a binary spatial weights matrix file (type of table)
Spline
a collection of vertices and connecting segments that form a line or curve.
Meridian
a line of longitude
Semivariogram
a model of the variance between points and their distance apart
Define TAXONOMY as it relates to spatial analysis
a scheme of classification
TIN (Triangulated Irregular Network)
a vector terrain model that allows for non-equally spaced elevation points to be used in the creation of the surface
What are the basic steps to overlay analysis methodology (based on Boolean logic)?
a. Define problem b. Break problem into submodels c. Determine significant layers d. Reclassify or transform data within a layer (e.g. union)
What is LEGIBILITY as it relates to the primary design principles for cartography?
ability to be seen AND understood.
Generalization
act of modifying detail, usually reducing it, in geospatial data -often done so data can be represented at "coarsened" resolutions -will introduce abstraction to the data, its symbolization, or both
Table row
also known as records, correspond with individual entities, such as customer accounts or a geographic point
Describe STATIC SECURITY TESTING
analyzes code at fixed points
What is Progressively Varying Continuous Surface Data?
as phenomena move across surface from source, they progressively vary
In a projected coordinate system, where do the x,y coordinate originate
at the center of the grid
What are some format-specific QA/QC items for point clouds?
check for correct components and values.
Describe the APPEND spatial data selection function
combines datasets of same data type into an existing dataset
Describe the UNION spatial data selection function
combines input features with another feature dataset
Describe the MERGE spatial data selection function
combines multiple input datasets of the same data type into a single new output
Describe INTERACTIVE SECURITY TESTING
combines static and dynamic testing
Describe the JOIN spatial data selection function
combines two attribute tables into one using a common key between tables
Information Systems
computer-based tools that help people transform data into information
What is the NSRS?
consistent coordinate system defined by NGS -defines latitude, longitude, height, scale, gravity, and orientation throughout the US
Table column
correspond with the various attributes associated with each row/record
What is the danger of choosing the wrong classification methodology?
could cause the data to hide important information or misinform the reader
What is a SELECTIVE AVAILABILITY GPS error?
d. Selective Availability - intentional degradation of the GPS signals by the department of defense (DOD) to limit accuracy for non-U.S. military and government users - currently turned off, but can turn it back on whenever
Information
data that has been selected or created in response to a question (e.g. location of building is data, until needed to dispatch ambulance in emergency.)
Geodataset
data that identifies the geographic location of features and boundaries on Earth
Tolerance (coverage)
define the resolution of coordinates in a coverage
Describe MOBILE SECURITY TESTING
designed to examine how an attacker can attack mobile apps
Metadata question: Who _____________ the data?
developed
What is the newer version of SSL?
TLS - transport layer security
Define a polygon in the context of vector development
A polygon is a series of line segments that begin and end at the same node / vertex
What does a phenomenon have to have in order to move by diffusion?
A source
What is a KMZ?
A zipped version of a KML file
What five organizations are members of the GISCI?
AAG GITA NSGIC UCGIS URISA
Data Consistency
Absence of conflicts in a particular database.
Describe Inspection as a data collection method
Data has already been geographically located and needs to be inspected
Atlas*GIS
(an evolutionary stage in the development of GIS) Desktop mapping system that combined some functions of CAD with simple linkages between location data and attribute data. -could produce a map with parcels automatically colored according to property values, for example -some desktop mapping systems supported simple, single attribute file queries -Most real-world decisions require queries involving multiple data files
What is COGO data entry?
(contraction of the term coordinate geometry) -methodology for capturing / representing geographic data. -uses survey-style bearings and distances to define each part of an object -very precise measurements -often regarded as the only legally acceptable definition of land parcels
Describe DIGITIZATION AND TRANSFER as it relates to data collection workflow
(longest portion of workflow)
What happens at the datelines when data is projected in a geographic coordinate system?
+180 and -180 lines are separated
What do a 0 and a 1 Coefficient of Determination mean?
- 1 indicates the line fits perfectly with the data -0 indicates the line does not fit at all (data is random)
What is .e00 (vector format)?
- ArcInfo Interchange File - known as ArcGIS export file
Describe the LOGICAL DATA MODEL step of the Database Design process
- Arrange data in a logical structure -Can be mapped into storage objects supported by DBMS
What does the WEIGHTED OVERLAY Raster Overlay Tool do?
- Automates the raster overlay process and lets you assign weights to each layer before adding -can also specify equal influence to create an unweighted overlay
Describe the CONCEPTUAL SCHEMA step of the Database Design process
- Determine where relationships and dependency are in data.
What is the GLOBAL IDENTIFIERS field type?
- Global ID or Globally Unique Identifier (GUID) -Registry style strings of 36 characters in curly brackets
What are HTTP Protocols?
- Hypertext Transfer Protocol - standard web transmission protocol - delivers map images or map data to web browsers
What does the SINGLE OUTPUT MAP ALGEBRA Raster Overlay Tool do?
- Lets you combine multiple raster layers using an expression you enter —e.g. you can add several ranked layers to create an overall ranking
What does the WEIGHTED SUM Raster Overlay Tool do?
- Overlays several rasters multiplying each by their given weight and summing them together.
What is PDOP?
- Position Dilution of Precision -lower PDOP value are preferred -higher PDOP values are bad) -PDOP values should be set to 6 or less
What is the WATERFALL application development method?
- Rigid linear model that contains sequential phases *Requirements *Design *Implementation *Verification *Maintenance - each phase must be complete before moving to next
What is RS Landsat?
- Satellite imagery and BIL information combined
What is the CONSTRUCTION PHASE of systems architecture design?
- System procurement -Data acquisition and database design -Authorization for application design and development -Prototype testing
What is the OBJECT IDENTIFIERS field type?
- Unique IDs and FIDs
What is an IF STATEMENT?
- a conditional expression that is either true or false
What is the HOSTED (CLOUD) GIS platform?
- access, make, share maps with any device, anywhere, anytime - access other users' maps and data - connect people outside of organization
What is the JENKS NATURAL BREAKS method of Quantitative Thresholding?
- aka Optimization -designed to optimize the arrangement of a set of values into "natural" classes. -minimize the average deviation from the class mean while maximizing the deviation from the means of the other groups.
What is a SPATIAL DOMAIN (in context of database object relationships)?
- allowable range for x, y coordinates and for m, z values
What is Versioning?
- allows multiple editors to edit one database by creating "duplicates" of the base data - changes are recorded with addition and deletion tables - versions can be created or deleted - edits are isolated in that version until admin merges changes - edits can be posted to parent version - DEFAULT is the root version
What is a RANGE DOMAIN (in context of database object relationships)?
- attribute domain -defines range of permissible values for a numeric attribute
What role does a .dbf play in a Shapefile?
- attribute information
Describe Explicit Reports (in terms of measurement)?
- beliefs people express about things - survey
What is an Enterprise GIS Environment?
- broad spectrum of technology integration -connected by local area networks, wide area networks, internet communications
What is a PACKAGE (in context of Database Object Relationships)?
- built from source with one of the available package management systems
What is an CREATOR in the context of database user access?
- can create additional feature classes, tables, as well as read, update, create, and delete features
What is an READER in the context of database user access?
- can only view data
What is an EDITOR in the context of database user access?
- can read, update, create, and delete features
What is a DATA DICTIONARY (in context of database object relationships)?
- catalog or table containing information about datasets stored in a database
What is an ELIF STATEMENT?
- check if a different condition from the first "if" is true
Sphere of Influence (spatial conceptualization)
-AKA Fixed Distance or Distance Band - A "sphere of influence" is created around the target feature (you decide -All features within the SoI impact the analysis of the target feature -Features outside the SoI have no impact on the analysis of the target feature
Distance Band (spatial conceptualization)
-AKA Fixed Distance or Sphere of Influence - A "sphere of influence" is created around the target feature (you decide -All features within the SoI impact the analysis of the target feature -Features outside the SoI have no impact on the analysis of the target feature
Fixed Distance (spatial conceptualization)
-AKA Sphere of Influence or Distance Band - A "sphere of influence" is created around the target feature (you decide -All features within the SoI impact the analysis of the target feature -Features outside the SoI have no impact on the analysis of the target feature
What are the five key areas of GIS that are being affected by changing trends?
-Access -Data Analytics -Infrastructure -Shaping the Future -Workforce
What are the basics of the OBLIGATIONS TO EMPLOYERS AND FUNDERS in the GISCI Rules of Conduct for Certified GISPs?
-Acknowledge and fix errors -Disclose conflicts of interest -Don't lie about credentials -don't discriminate based on race, religion, etc -Don't use their equipment for private work unless given permission -don't sell services by falsely claiming outcomes you cant provide -Don't do anything fraudulent, illegal, or unethical -provide sufficient metadata
What are the basics of the OBLIGATIONS TO SOCIETY in the GISCI Rules of Conduct for Certified GISPs?
-Acknowledge errors -Don't alter data outside of accepted procedures -Don't knowingly spread bad data -work should benefit society -Confront other GISPs violating code of ethics -do not perform assigned work that is unethical
What are the ways you can SELECT features based on ATTRIBUTE?
-Add to Selection -Clear Selection -New Selection -Remove from Selection -Subset Selection -Switch Selection
Define spatial intersection (as it relates to map overlay)
-Adding more than one layer of data into a map to see where they do and don't intersect -The digital way of laying maps over each other but, in GIS, you have the ability to generate a new data layer as a product of those layers
What are the most common types of User Access in database management?
-Administrator -Editor -Reader -Creator
Cartographic Effects (source of discrepancy)
-After capturing the data, some cartographic effects like symbology, pattern, colors, orientation, and size must be assigned according to the domain of the features. -Elements of any other domain used for a particular domain degrades the output of results.
What are some ways generalization can be achieved in a map?
-Aggregating - combining into a new composite feature -Only selecting certain features to be displayed -Removing detail -Dissolving/Merging (e.g. combine similar neighbor elements) -Exaggerating - make features larger than they are -Smoothing out detailed /complicated features (e.g. rivers do not need every curve)
What are the types of application development methods?
-Agile -DevOps -Rapid application development (RAD) -Spiral development -Waterfall
What are SYNONYMS (in context of database object relationships)?
-Alias or alternate name for a table, view, sequence or other object
Multi-Criteria Evaluation (MCE)
-Allows map layers to be weighed to show the relative importance of different variables. -Does not rely on threshold values unlike vector/raster overlay (i.e. no problem of fuzzy boundaries) -Problem how to determine relative weight of each variable different for different people.
What is an enterprise geodatabase?
-Also known as multiuser geodatabases -can be unlimited in size and numbers of users. -Stored in a relational database
Inverse Distance (spatial conceptualization)
-Among features in a dataset, features farther away from each other exert less influence on each other (though they still have influence) -Default calculation is to include every feature in a dataset in the analysis -This will bog down the calculation in a large data set; in that case, you need to choose a threshold/cut-off distance outside of which features don't exert influence -There are three kinds of inverse distance
What are the restrictions regarding which geometries can and can't Contain?
-An object can never contain a shape of higher order -Points can never contain anything -Lines can't contain lines or polygons -Polygons can contain points, lines, or polygons -Can lines contain points??
What are the advantages to using RASTERS?
-Analytical operations are easier -Easy to draw on a screen -Easy to input and output -Good to represent surfaces -Easy to understand
What is an API?
-Application Programming Interface - data is accessed and exchanged as needed between software systems
Where can Representations be created or managed?
-ArcCatalog -From symbolized layers in ArcMap
What are some VECTOR formats?
-ArcInfo Coverage -ArcInfo Interchange File (.e00) -Digital Exchange Format (DXF) -Digital Line Graph (DLG) -Geodatabase -PostScript -Shapefile -Scalable Vector Graphics (SVG) -TIGER
What are the 5 types of measurement?
-Archives -Computational modeling -Explicit reports -Observation of behavior -Physical
What are the five types of measurement?
-Archives -Computational modeling -Explicit reports -Observation of behavior -Physical measurement
In cartography, how can surfaces be represented?
-Arrays of points -Contour or iso-lines -Rasters -TINs
Describe the raster sampling approach
-As with vectors, attributes are sampled at fixed intervals. -Unlike vectors, each sample represents one cell in a checkerboard-shaped grid (as opposed to vectors in which each sample is represented by a single node).
What does the COMBINE Raster Overlay Tool do?
-Assigns value to each cell in output layer based on unique combinations of values from several input layers.
What are some arguments why government-owned GIS data should be freely available to the public?
-Citizens should have access to information government uses in order to have effective input into decisions. -Costs can be prohibitive to any but very large organizations. -Government branches may horde data for bargaining power with other agencies. -Liability increased if data sold in commercial transaction. -Research opportunities lost due to expense -Sales don't really recoup the costs for the agency anyway. Distribution is cheap.
Ellipsoid
-Closed surface -All plane cross sections are either ellipses or circles -symmetrical about three mutually perpendicular axes that intersect at the center
Zone of Indifference (spatial conceptualization)
-Combination of Inverse Distance and Fixed Distance conceptualizations -A "critical distance" radius is defined (similar to a Sphere of Influence) -Features inside the critical distance radius exert the most influence over the analysis of the target feature -Features outside the critical distance radius exert some influence over the analysis of the target feature, but not as much
What is CIFS?
-Common Internet File System -network file system protocol -provide shared access to files and printers between machines on network. -client application can read, write, edit and remove files on remote server
CAD
-Computer-aided design systems -originally developed to create and revise precise drawings (for things like machine parts, construction plans, etc) -stores data in vector format
What are the three main steps to the Database Design process?
-Conceptual schema. -Logical Data Model -Physical database design
What are the basics of Scripting?
-Condition statements -Expression -Iterations -Variables
If developing standards were a symphony, what would be ISO's role?
-Conductor -the orchestra is made up of independent technical experts nominated by members.
Describe the PHYSICAL DATABASE DESIGN step of the Database Design process
-Configuration of database on storage media -Detailed specification of: -data elements and types -indexing options -modules -hardware -software
What are the methods of spatial selection involving CONTAIN?
-Contains - features contain an input polygon -Completely contains - features must be completely in an input polygon -Contained by - Same as within -Contains Clementini - features must be completely in the input polygon but if it's on the boundary, it will not be selected
What are NON-SCHEMA FUNCTIONS (in context of Database Object Relationships)?
-Contexts -Directory Objects -Roles -Users
List the most common conceptualizations for spatial relationships
-Contiguity -Fixed distance AKA Distance band (sphere of influence) -Inverse distance (impedance) -K Nearest neighbor -Natural neighbors (Delaunay triangulation) -Travel time -Zone of indifference (combo of Inverse and Fixed distance conceptualizations) -User-defined conceptualizations
What are 4 other names by which CONTINUOUS is known?
-Continuous surface -Field data -Nondiscrete data -Surface data
What is CORS?
-Continuously Operating Reference Station -GPS data positions can be improved by using CORS data -CORS enhanced coordinates horizontally and vertically approach a few centimeters relative to the NSRS
What are the limitations of a data source completed by multiple individuals?
-Could be more accurate due to many contributors --Could be inaccurate due to it relying on individuals and not having a QA/QC process
Cost Surface Raster
-Created in Spatial Analyst -identifies the cost of traveling through each cell -eg cost of constructing a road through each cell --Land use and slope influence the construction costs. ----Different measurement system (land-use type and percent slope), so they cannot be directly compared to one another and must be reclassified to a common scale -Three steps 1. Reclassifying your datasets to a common scale 2. Weighting datasets according to percent influence 3. Combining the datasets
How does Geostatistical interpolation work (surface development)?
-Creates predicted value surfaces derived from statistics -allows for interpretation of certainty levels about the predictions.
What are the four things that Spatial Models "do"?
-DATA (Use spatial data) -COMBINE (Use combined tools (e.g. GIS and programming languages)) -MEANING (Focus on meaning, not just the analytical tools) -REPRESENT (Represent meaningful features, events, and processes in space)
Object database
-DBMS in which information is represented in the form of objects -Different from relational databases which are table-oriented.
What are the three general categories that temporal data may refer to?
-DISCRETE events (e.g. lightning strikes) -MOVING objects (e.g. trains) -REPEATED observations (e.g. counts from traffic sensors)
What are the five components of GIS?
-Data -Hardware -Methods -People -Software
What are some sources of spatial data discrepancy?
-Data Information Exchange -Type and Source -Data Capture -Cartographic Effects -Data Transfer -Metadata
What are some methods to prevent unauthorized access to data and metadata?
-Data authenticity verification -Define who has access -Identify management systems to check user credentials -Use other software to enforce policies
What are the essential elements of a map?
-Data frame (portion that displays layers) -Legend -Title -North arrow -Scale and scale bar -Citation/sources -Creator/creation date/update date -Projection
Goodchild's three categories of Spatial and GIS models?
-Data models -Static modeling -Dynamic modeling
Nominal Data
-Data of categories only. -Data cannot be arranged in an ordering scheme. (Gender, Race, Religion)
What are INDEXES (in context of database object relationships)?
-Data structure that improves retrieval speed in database table *Causes more storage space and additional writes
Delaunay Triangle
-Method for connecting nodes of Voronoi Diagram into triangular regions -essential in process of creating Voronoi diagrams. -no other nodes exist within the circumcircle of each particular triangle. -each triangle is formed by connecting each node to its nearest neighbors. -Method is often used to build TIN surfaces -AKA Thiessen Polygons
What are two examples of the inherent characteristics of the moving item (mode of locomotion) type of movement?
-Movement of noise from a bomb blast is governed by the inherent characteristics of noise and the medium through which it moves. -Seed dispersal from a plant will vary depending on the means of locomotion (bees, man, wind, or water)
What are some common GPS errors?
-Multipath -Atmosphere -Distance from Base Station -Selective Availability -Noise
What are the disadvantages to using VECTORS?
-Multiple vectors overlay is computationally intensive -Display and plotting vectors can be expensive -Less intuitively understood
What is NAVSTAR?
-NAVigation Satellite Timing and Ranging constellation a. Satellites that transmit signals on two phase modulated frequencies b. Transmit orbital data for computing positions of all satellites
Travel Time (spatial conceptualization)
-NO DEFINITION OR DESCRIPTION; ASK ROB
What is NCS?
-National CAD Standards -collaborative effort CAD and building information modeling (BIM) users'-goal is to create a unified approach to the creation of building design data
What is the NGS?
-National Geodetic Survey -Division of NOAA -provides framework for all positioning activities in U.S. (foundational elements of latitude, longitude, elevation, and shoreline information)
What is the NSRS?
-National Spatial Reference System -the official, common federal system for establishing coordinates for geospatial data that are consistent nationwide.
What are additional helpful elements of a map?
-Neatline -Inset map -Company / client logo
What is NFS?
-Network File Services -distributed file system protocol -user on client computer can access files over a network (like local storage is accessed). -open standard
Floating Point Numbers
-Numbers with no fixed number of digits before and after the decimal point (decimal point can "float") -Slower and less accurate than fixed-point numbers -Can handle larger range of numbers
Contains (topological relation)
-Object A contains Object B -this is the opposite way of saying the same thing as "within" i.e. If Object A contains Object B, then Object B is within/inside Object A a ∩ b = b
Within / Inside (topological relation)
-Object B lies within/inside Object A -this is the opposite way of saying the same thing as "contains" i.e. If Object B is within/inside Object A, then Object A contains Object B a ∩ b = a
What is OOP?
-Object Oriented Programming -based on concept of "objects" that are data structures -objects contain data in form of fields (aka attributes) -code is in form of procedures (aka methods) -most common are class-based
What are the restrictions regarding which geometries can and can't Cover?
-Object can't cover an object of higher dimension -Polygons can cover anything -Lines and points can't cover anything (??)
Micron
-One millionth of a meter -Unit used in scanning to determine pixel sizes
What is the OGC Abstract Specification?
-Open Geospatial Consortium Abstract Specification -Roadmap to support goal of interoperability -Reference model for development of OGC Implementation Standards
PostGIS
-Open-source software program -Adds support for geographic objects to the PostgreSQL object-relational database.
What are two ways to achieve AUTHENTICATION in the context of database security?
-Operating System (OS) authentication -Database Authentication
What database types can be used to store an enterprise geodatabase?
-Oracle -Microsoft SQL Server -IBM DB2 -IBM Informix -PostgreSQL
What are examples of Rendered file formats?
-PSD -PSB -TIFF -JPEG -GIF -PNG
In XML, what is an empty element?
-Pair of start- and end-tags with nothing between them *<price retail="123"></price>) OR -Single empty element start-tag that has a closing slash *<price retail="123"/>
What is .mdb?
-Personal Geodatabase -All datasets are stored within a Microsoft Access data file - Limited in size to 2 GB
What is the NGDA Cultural Resources Theme?
-Places of significance in history, architecture, engineering, or society -Includes National Monuments and Icons.
What is the order of data collection workflow?
-Planning -Preparation -Digitizing and transfer -Editing -Evaluation
Name the three main spatial data types used to model single, self-contained objects
-Points -Lines -Regions (aka Coverage)
What are the restrictions regarding which geometries can and can't Intersect?
-Points can never intersect anything -Lines can insect each other and polygons -Polygons can intersect each other and linesterm-33
What are the restrictions regarding which geometries can and can't Equal?
-Points can't equal lines or polygons -Lines can't equal points or polygons -Polygons can't equal points or lines
What are the restrictions regarding which geometries can and can't Touch?
-Points can't touch points
What are the restrictions regarding which geometries can and can't be Covered By?
-Polygons can be covered by other polygons -Lines can be covered by polygons
What is SSL?
-Secure Sockets Layer -protocol -establishing authenticated and encrypted links between networked computers
What are the restrictions regarding which geometries can and can't be Inside?
-Polygons can't be inside points or lines -Polygons can only be inside other polygons -Lines can't be inside points or lines -Lines can only be inside polygons -Points can't be inside points or lines -Points can only be inside polygons
What are the most common representations for the object-based data model?
-PostGIS -OMT-G -Entity relationship (?) -GraphDB -GEIS -GeoOOA -Oracle Spatial -Grass GIS
What is PPS?
-Precise Positioning Service -one of the two original services provided when GPS first developed -military positioning, velocity and timing service -highly accurate -Broadcasted at GPS L1 and L2 frequencies. -L1 and L2 contain an encrypted precision (P/Y) code -reserved for authorized users.
Coverage Data Model
-Precursor to shapefile -Topology data was stored in the file -(with shapefiles, topology data is not stored in the file)
What are the two KEYS in Relationship class properties?
-Primary -Foreign
David Cowen
-Professor at U of South Carolina -worked for 30+ years to demonstrate how g GIS can increase the effectiveness of many public sector -Defined GIS as "a decision-support tool that combines the capabilities of a relational database management system with the capabilities of a mapping system (1988)."
Max J. Egenhofer
-Professor at UofMaine -Major contributor to the theories of geospatial topology -created the 9-intersect model for topological relations (DE-9IM)
What are active sensors in remote sensing?
-Provide their own source of energy to illuminate the objects they observe. -Emits radiation in the direction of the target to be investigated. -Sensor then detects and measures the radiation that is reflected or backscattered from the target
EPSG Geodetic Parameter Dataset
-Public registry of: *Coordinate transformations *Earth ellipsoids *Related units of measurement *Spatial reference systems -Each entity is assigned: *EPSG code (1024-32767) *standard machine-readable well-known text representation.
What classification method is used for choropleth and isarithmic maps?
-Quantitative Thresholding -Dividing range of values of single quantitative attribute into ordinal classes
What are Descriptive Statistics?
-Quantitatively describe main features of a group -e.g. Summarizes a sample to learn about population
What are some examples of active remote sensors?
-RADAR -LiDAR
What are the four types of resolutions in Remote Sensing?
-Radiometric -Spatial -Spectral -Temporal
What is the RAD application development method?
-Rapid Application Development - condensed -produces high quality system with low investment costs
ArcGIS supports the display of what two types of surface models?
-Raster -TIN
Which process is more difficult: VECTORIZATION or RASTERIZATION?
-Rasterization is very difficult -pixels may distort lines or exact point locations and would need to be re-digitized
What are the three types of GPS receivers?
-Recreational Grade -Mapping Grade -Survey (High Accuracy) Grade
How do reference maps and thematic maps differ when it comes to hierarchical organization?
-Reference maps: *many features no more important than one another *lie on essentially the same visual plane. *hierarchy is usually more subtle -Thematic maps: *theme is more important than base
How are POINTS used in the context of cartography and SURFACES?
-Regularly or irregularly distributed across a surface. -Used as input to interpolation, kriging, or triangulation tools to create raster or TIN surfaces
Data Quality Improvement Techniques
-Relevant data from a relevant source. -Derive precision in the origin itself. -Data quality testing in each phase of data capture. -Using automated software tools for spatial and non-spatial data validation. -Assessment of the mode of data uses and user. -Determining map elements like scale, visualization and feature orientation.
Orthorthorectification
-Removing effects of image perspective (tilt) and relief (terrain) effects so that image becomes planimetrically correct. -An orthorectified image has a constant scale -Features are represented in their 'true' positions
What are ITERATIONS (in the context of Scripting)?
-Repeating process to generate an outcome e.g. For x in range (0, 3): In Python, this would take the variable x from 0 to 2, running it 3 times
What are surfaces in the context of cartography?
-Represent phenomena that have values at every point (infinite number of points). -Values are derived from a limited set of sample values
What are the advantages to using VECTORS?
-Represent point, line, area very accurately -More efficient in storage -Enables map generalization -Interactive retrieval -Supports topology
What are the phases of systems architecture design?
-Requirements Phase -Design Phase -Construction Phase -Implementation Phase
Georgy Voronoi
-Russian mathematician (28 April 1868 - 20 November 1908) -Created the Voronoi Diagram, a mathematical way to divide a plane filled with unique nodes into separate regions
Boris Delaunay
-Russian mathematician (March 15, 1890 - July 17, 1980) -Student of Georgy Voronoy -developed a method for connecting nodes of Voronoi diagrams into triangular regions
Ratio Data
-Same properties as interval data EXCEPT -No negative numerical value in ratio data -Equal and definitive ratio between each data -Absolute "zero" is treated as a point of origin
What are two benefits of automating data collection?
-Save time -Help to avoid errors that happen during manual collection
What is SVG (vector format)?
-Scalable Vector Graphics -Extension of XML
Describe the basics of a projected coordinate system
-defined on a flat, two-dimensional surface. -has constant lengths, angles, and areas across the two dimensions. -always based on a geographic coordinate system that is based on a sphere or spheroid. -locations are identified by x,y coordinates on a grid
What is the Coefficient of Determination?
-denoted R2 or r2 -pronounced "R squared" -proportion of variance in dependent variable that is predictable from independent variable -i.e. number indicating how well data fit a statistical model
What is Extensibility?
-designing to allow addition of new capabilities or functionality
What is a NOISE GPS error?
-distortion of satellite signal prior to reaching GPS receiver OR -additional signal piggy backing onto the GPS satellite signal
How is temporal GIS applied in the field of environmental science?
-e.g. hazard assessment of localized chemical spills, -e.g. characterization of regional resource use -e.g. evaluation of the global effects of climate change
How is temporal GIS applied in the field of transportation?
-e.g. model the changes in a public transit network and its use throughout different time periods
Z value
-elevation assigned to an x/y coordinate -attribute of the surface in continuous data
What are some format-specific QA/QC items for tabular data?
-ensure values pass logical tests -check integration with spatial details.
What is the OMB Circular A-16?
-establishes a coordinated approach to electronically develop the NSDI -establishes the FGDC -provides direction for federal agencies that produce, maintain, or use spatial data -provides for improvements in the coordination and use of spatial data. -describes effective and economical use and management of spatial data assets in the digital environment
Describe PLANNING as it relates to data collection workflow
-establishing user requirements -garnering resources -developing a project plan
How does Inverse Distance Weighted (IDW) interpolation work (surface development)?
-estimates surface values for each cell using weighted average of values of a set of nearby points -nearby points have more influence than distant points
What are the two aspects that each component of scale has?
-extent (or coverage) -grain (or resolution).
What does ETL mean?
-extract, transform, load -three functions combined into one tool to pull data out of one database and place it into another database
What is RETRIEVAL in the context of database administration?
-extracting data from a backup due to data loss or data corruption
What are some formats in which you can store and manage temporal data?
-feature classes -mosaic dataset -raster catalogs
What are some examples of passive remote sensors?
-film photography -infrared, charge-coupled devices -radiometers
What is the STANDARD DEVIATION method of Quantitative Thresholding?
-finds the mean value of the observations -then places class breaks above and below the mean at intervals of either .25, .5, or 1 standard deviation until all the data values are contained within the classes. -shows how much the feature's attribute value varies from the mean.
What is the DOUBLE field type?
-floating-point numbers -double-precision (more sig figs)
What are Rendered file formats?
-formats ready to be edited in a bitmap graphics editor (e.g. Photoshop).
What is an ADMINISTRATOR in the context of database user access?
-full control of database -can read, create, update, and delete features, feature classes, and tables
What is the OMB Circular A-16 Supplemental Guidance?
-further defines and clarifies elements of OMB Circular A-16 t -improves support of mission-critical business requirements of the Federal Government -provides foundation for a portfolio management approach to NGDA Theme and their associated NGDA Datasets.
When constructing a dot map, what two parameters must be considered?
-graphical size of each dot -value associated with each dot. e.g. each dot is 2 pixels in diameter, and each represent 100 persons.
Discrete Data
-has known and definable boundaries -easy to define precisely where object begins and ends -Discontinuous -Numerical data values that can be COUNTED
What is Transmission Control Protocol (communication packet interval)?
-header package for data at transport layer
When would you want to use a high vs low visual contrast in a map?
-higher contrast between features means some features will stand out more -lower contrast between features can be used to promote a more subtle impression, features appear to belong together.
What is the most important things for map users to understand when they're interpreting a spatiotemporal map?
-how the data was sampled: *regular intervals (e.g. every ten years) *only when a change has taken place (e.g. before and after a war).
How is Enterprise GIS different depending on whether it utilized hosted (cloud) and server platforms?
-if organizational data is not stored in cloud (only data is accessed from cloud), it's not quite an enterprise system
What other important data can be stored in and represented by rasters?
-imagery -scanned maps -categorical information (e.g. land use class)
Describe the trend of Miniaturization of Technology
-increase data collection -Smaller and lower-cost sensors -improve ability to use sensor for specific data collection needed.
What is the DESKTOP GIS platform?
-individual user on a computer -make maps, data analysis, data creation
What are the basics of the OBLIGATIONS TO INDIVIDUALS IN SOCIETY in the GISCI / URISA Rules of Conduct for Certified GISPs?
-provide accurate info -listen to and consider feedback -Disclose use of others' personal data -don't use others' confidential/personal info for your personal gain -respect and protect privacy
In what ways are DBMS valuable?
-provide secure means of storing and updating data -admins can protect files so that only authorized users can make changes. -have functions that allow multiple users to edit the database simultaneously. -retrieve data that meet user specified criteria (perform a query)
What is HARN?
-readjustment (for more accuracy) of NAD 1983 datum -all states except Alaska have been resurveyed -labeled in NGS database as NAD83 (19xx) or NAD83 (20xx) where xx represents the year of adjustment
Describe recent changes in Real-time Data
-recent ability to continuously create and interact in real time with spatiotemporal data -expanding research opportunities -changing how geographic data is *Collected *Mapped *Modeled *Used
What is GIS Feature Data Archiving?
-record and access changes made to all or subset of data in a versioned geodatabase
What is PHYSICAL measurement?
-recording physical properties -e.g. size, number, temperature
Describe Physical Measurement?
-recording physical properties of the earth or its inhabitants -e.g. size, number, temperature, chemical makeup, moisture, etc.
Table row
-records -correspond with individual entities (e.g. customer accounts or a geographic point)
Describe Archives (in terms of measurement)?
-records collected primarily for non-research purposes -secondary data
What is a raster?
-rectangular arrays of cells ("pixels") -each pixel stores single value for part of surface it covers. .
What is the benefit of the JENKS NATURAL BREAKS method of Quantitative Thresholding?
-reduces variance within classes and maximizes variance between classes.
Radiometric Resolution
-refers to how much information is in a pixel -expressed in units of bits. -the degree of a sensor's ability to determine fine differences in a band of energy measurements
Spectral Resolution
-refers to the ability of a satellite sensor to measure specific wavlengths of the electromagnetic spectrum. -The finer the spectral resolution, the narrower the wavelength range for a particular channel or band.
Spatial Resolution
-refers to the size of the smallest feature that can be detected by a satellite sensor or displayed in a satellite image. -usually presented as a single value representing the length of one side of a square e.g. a spatial resolution of 250m means that one pixel represents an area 250 by 250 meters on the ground.
What is BALANCE as it relates to the primary design principles for cartography?
-results from two primary factors: *visual weight *visual direction. -If center of your map page is balancing on a fulcrum, factors that will tip it include: -relative location -shape -size -subject matter of the elements
What can the fractal technique be used for (relative to Resolution)?
-reveal multi-resolution property of a phenomenon -help guide selection of resolution level for a study.
Sphere
-round solid figure -every point on its surface equidistant from its center
What is the STANDARD RASTER Format?
-rows and columns with a header information
What is Photogrammetry?
-science of making measurements from photos/images. -measurements captured from overlapping pairs of photographs using stereo plotters
What are ARCHIVES (in terms of measurement)?
-secondary data -records that have been collected mostly for non-research purposes
Why are proper Field Types important to Database Design?
-secure data and make databases more efficient
What role does a .shx play in a Shapefile?
-shape index format -positional index of the feature geometry to allow seeking forwards and backwards quickly
What is the general rule of thumb about colors in map-making?
-should align with expectations whenever possible -E.g. grass is green, ponds are blue, etc
What is the general rule of thumb about labels in map-making?
-should be hierarchical based on importance relative to message of map
Describe SPATIAL RASTER RESOLUTION
-size of object that can be resolved -most usual measure is pixel size
What is FIGURE-GROUND ORGANIZATION as it relates to the primary design principles for cartography?
-spontaneous visual separation of figure in foreground from an amorphous background.
What is a schema?
-structure of the dataset -physical representation of the data -defines the feature type name, attribute names, attribute data types, and permitted geometry type.
What is Spatial Overlay?
-superimposing layers of geographic data that cover the same area to study the relationship between them
In a projected coordinate system, what do the x,y coordinates reference?
-the center of the grid. -one specifies its horizontal position and the other its vertical position.
Isarithmic Map
-thematic map -isolines (lines of equal value) are interpolated between points of known value e.g. levels of snowfall, heat map
What is Overlay?
-two or more maps or layers are superimposed for showing relationships between features
What is the Media Access Control (MAC) address (communication packet interval)?
-unique identifier -used as network address in communications within network segment -added at the physical network layer
ISO/TC
Technical Committee within ISO
Describe the three basic requirements/steps to identify parcels located within a mile of a heavy-duty highway
1. Digital map and associated attributes that allow heavy-duty highways to be differentiated from features. 2. A buffer operation creates a polygon that surrounds all "heavy duty highway" features at the specified distance. 3. A spatial intersection is then performed to isolate the parcels within the buffer from those outside the buffer. (e.g. Selection by Location)
How do you calculate DPI from microns?
1. Divide microns by 1,000,000 2. Multiple the answer by 39.37 3. Calculate inverse of that (divide 1 by that answer)
What are the nine topological relations derived from the DE-9IM?
1. Equal 2. Disjoint 3. Touches/meets 4.Contains 5. Within/Inside 6. Covers 7. Covered by 8. Intersect 9. ?
What are two other names for the Sphere of Influence spatial conceptualization?
1. Fixed Distance 2. Distance Band
What are two other names for the Distance Band spatial conceptualization?
1. Fixed Distance 2. Sphere of Influence
What is the ranking order of geometry features (1 being highest)?
1. Polygons 2. Lines 3. Points
What are two other names for the Fixed Distance spatial conceptualization?
1. Sphere of Influence 2. Distance Band
What are the three main types of spatial relations?
1. Topological Relations 2. Directional Relations 3. Distance Relations
What are the different intervals at which a communication packet is constructed?
1. Transmission Control Protocol 2. Internet Protocol 3. Media Access Control (MAC) address 4. Transferred from the host to the receiver
Four questions to ask before starting a modeling process?
1. What do we want the model to tell us? 2. What type of data do I need? 3. How do I create a design to put the model together? 4. How do I apply existing tools to create a meaningful model?
You have a paper map of parcels and corresponding data about those parcels. What are the first two things you need to do to?
1. digitize the paper maps 2. produce corresponding attribute tables
How did temporal modeling in computer sciences begin?
1. integration of time with relational databases 2. later, extended into object oriented modeling.
What are the three main transfer constructs (based on data models)?
1. logical constructs solely pertaining to this standard 2. constructs relating to the implementation method 3. constructs solely pertaining to the transfer media
What version is TLS on?
1.3
What is the average altitude of GPS satellites?
12,000 miles
When was Executive Order 12906 created and then amended?
1994 (Bill Clinton) 2003 (George W. Bush)
Which scale is larger: 1:25,000,000 or 1:10,000?
1:10,000
What are some examples of projection parameters?
1st standard parallel 2nd standard parallel Central meridian Latitude of origin False easting False northing Unit of measure
What are the two ISO Technical Committees involved in the standardization of various aspects of geographic data and geoprocessing?
211 and 287
Are most larger scale print maps 2D or 3D?
2D
How often do GPS satellites orbit Earth?
2x per day
What is the pixel limit of PSD?
30,000 x 30,000
How many seconds are in one degree?
3600
How many inches are in a meter?
39.37
You have a scanned image with an original scale of 1:80,000 and a DPI of 1282. What is the GSD in feet?
5.2' (80,000 / 1282 / 12)
How many minutes are in one degree?
60
How does a DBMS perform a Join?
A DBMS can relate one file to another when they share a unique identifying attribute (e.g. FIPS Code, ID number etc). If two data files have at least one common attribute, a DBMS can combine them in a single new file. The common attribute is called a key.
Datum Shift
A change from one datum to another, such as from NAD27 to NAD83, which can result in substantial horizontal shifts of point positions
Complete-Data
A data set with minimal amount of missing features
Document Type Definition (DTD)
A file with a .dtd extension that describes XML elements -describes a document's composition and defines the syntax rules or valid tags for each type of XML document.
What is the main drawback to using CAD systems to analyze spatial data?
CAD systems typically do not encode data in forms that support spatial queries. (e.g. a CAD system would be useful for depicting the streets, property parcel boundaries, and building footprints of a residential subdivision. The operator could highlight a particular parcel with a selected color or pattern. However, CAD cannot typically be used to automatically shade each parcel based on values in an assessor's database, like property value)
What are CLUSTERS (in context of database object relationships)?
Can be either: -Multiple servers share one storage OR -Databases distributed to different servers using replication
Why is data quality so important in GIS?
Can only get meaningful results from high-quality data
What are three other names by which "discrete data" can be known?
Categorical Data Discontinuous Data Thematic Data
What is the main challenge cartographers face when showing spatial change over time?
Change over time is 4D, but trying to show it in 2D
What are the steps to checking a data model?
Check the: -Attribute names and types. -Coordinate system -Allowed geometries -Feature type (e.g.feature class) names
OGC compliance standards include:
Checking for: -Repeated points -Self-intersection -Unparsable geometry, etc.
What is Identification Information (in metadata)?
Citation-level information about the data, for example: -title -abstract -purpose for creation -status -keywords (theme and place) -extent (temporal, vertical and horizontal).
What spheroid does NAD 27 use?
Clarke 1866 spheroid
Name one of the three schemes of classification of operators for spatial analysis (1)
Classes of techniques (e.g. queries; looking at forest fires and comparing burnt with non burnt areas, distances between burnt areas, etc) -aka the exploratory/descriptive approach
What is the OGC Innovation Program?
Collaborative Research and Development (R&D) lab
Database
Collection of tables (data files in tabular format)
What is DATA INTEGRATION?
Combining data from multiple sources into one unified view
What is CEN?
Comité Européen de Normalisation -engaged in geographic standardization
Descriptive summaries (techniques of spatial analysis)
Compute summary statistics for an entire collection of features
CAD
Computer-aided design systems that were originally developed for engineers, architects, etc who needed more efficient means to create and revise precise drawings (for things like machine parts, construction plans, etc) -stores data in vector format
Name one of the three schemes of classification of operators for spatial analysis (2)
Conceptual models (e.g. entities vs. fields - Burrough and McDonnell 1998) -aka the explanatory/confirmatory approach
Topological model
Construction of a topological network to reflect the shape of a dataset)
What is the long time FGDC endorsed geographic metadata standard?
Content Standard for Digital Geospatial Metadata (CSDGM)
What is the cause of the drawbacks to 3D/oblique projections?
Convergent projection lines
Geocoding
Converting addresses (like a street address) into geographic coordinates (like latitude and longitude).
What was the first main challenge faced by people working on developing digital mapping and CAD systems?
Converting from paper maps into digital data
What is Rasterization?
Converting vectors into rasters.
What is Executive Order 12906?
Coordinating Geographic Data Acquisition and Access: the National Spatial Data Infrastructure
Transformations (techniques of spatial analysis)
Create new features from existing features
Tables
Data files in tabular format
What is the major limitation of using another entity's collected GIS data?
Data gathered for one project may not fully encompass the needs of a different project
EPSG
European Petroleum Survey Group
Say you're rasterizing a forest and a lake from the same photo. How do you treat the grid cells that overlap the lake, the forest, or both?
Every grid cell that overlaps one of the two selected entities is encoded with an attribute that associates it with the entity it represents. -e.g. in the simplest representation, the lake could be coded as "1" and the forest could be coded as "2"
What is a major drawback to ground survey for data collection?
Expensive and time consuming
What is ETL?
Extract, Transform, Load (ETL) methodology
What is the example given of spatial analysis with a taxonomy built based on the data model (aka analysis for criteria evaluation)?
FOREST FIRES -Overlay of layers to quantify, do suitability analysis, formulate functions
What is the example given of spatial analysis with a taxonomy built from techniques of classes (aka exploratory/descriptive approach)?
FOREST FIRES -comparing burnt with non burnt areas -distances between burnt areas, -mean/median size of burnt patches
What is the example given of spatial analysis with a taxonomy built based on conceptual model (aka explanatory/confirmatory approach)?
FOREST FIRES -try to explain causes by analyzing and exploring available data -Formulate hypotheses (land use, climate conditions, etc) -Sampling -Regression Analysis
What is the NGDA Utilities Theme?
Facilities for distributing, processing or producing public and private power, energy, communications, natural gas, and water. Sub themes: -Energy -Drinking water and Water treatment -Communications
What is the output of the SYMMETRICAL DIFFERENCE tool in the context of Vector Overlay Tools?
Features common to either input layer or overlay, layer but not both
When representing digital geographic data, which features are well-suited to being represented as rasters?
Features that don't have well-defined boundaries -e.g. elevation, terrain, preceipitation
When representing digital geographic data, which features are well-suited to being represented as vectors?
Features with defined edges -e.g. roads, property parcels, pipelines, small bodies of water -features commonly found on maps, like roadways, political boundaries, contour lines, etc
What is FGDC?
Federal Geographic Data Committee -US government committee -Development, use, sharing, and dissemination of geospatial data nationally
Visually, how is the Coefficient of Determination represented?
Fit to a line or curve
Metadata question: In what _____________ are the data available?
Formats
What are the SGML-family markup languages?
GML HTML (not HTML 5 or newer) SGML XML
What spheroid does NAD 83 use?
GRS 1980 spheroid
What are passive sensors in remote sensing?
Gather radiation that is emitted or reflected by the object or surrounding areas.
What is Metadata Record Information?
General information, for example: -language in which the record is written -unique file identifier for record -metadata standard used t -point of contact for the record -date that the metadata record written.
What is the most basic use of classification in GIS, cartography and remote sensing?
Generalize complexity in and extract meaning from geospatial data.
What is GML?
Generalized Markup Language -Macros that implement markup tags for IBM text formatter, SCRIPT.
What does GRS stand for?
Geodetic Reference System
What is the GIS&T BoK?
Geographic Information Science & Technology Body of Knowledge
What are the two types of coordinate systems?
Geographic and projected
What happens to features at +/-180 (dateline) when mapped ?
Geographic coordinate system: feature that crosses outside the horizon will be clipped to the horizon In a projected coordinate system (+/-180° line inside), a feature crossing dateline will be split into multiple parts.
Describe the vector sampling approach
Involves sampling locations at intervals along the length of linear entities (like roads), or around the perimeter of areal entities (like property parcels). -When the sampling locations (vertices) are connected by lines, they form line features and polygon features that are shaped like their real-world counterparts.
What is Cardinality in terms of Relationship class properties?
Is the relationship: *one-to-one *one-to-many *many-to-many
What benefit does he simplicity of the raster data structure provide?
It akes calculations on rasters (or comparisons between rasters) faster than other surface representations.
-Why is it useful for a feature class to have more than one representation associated with it?
It allows the same data to be displayed uniquely on different maps
How is metadata similar to a library catalog?
It records the who, what, when, where, how, and why of a data resource
Why is spatial decision making subjected to uncertainty?
Its operations involve discretization and generalization on the geographical data set.
What is KML?
Keyhole Markup Language -XML notation -Used to display geographic data in Google Earth -an international standard of the OGC
What are "spot heights" in TIN construction?
Known values used as initial nodes in triangulation
As a rule of thumb, show should water be symbolized and labeled in a map?
Labels = italics Color = blue.
How would describe a "lake" in generic vector terms?
Lakes are an example of areal entities
What is the NGDA Soils Theme?
Large and small map scales of geography and attributes of soils
Does large scale or small scale show more detail?
Large scale
What is the NGDA?
National Geospatial Data Asset -GeoPlatform -Open geospatial data portfolio developed by the FGDC -Target audience for the GeoPlatform includes Federal agencies, State, local, and Tribal governments, private sector, academia, and the general public.
What is NIST?
National Institute of Standards and Technology
How did GIS originate (broadly)?
Need to perform spatial queries on geographic data.
Is AFPO scanned imagery georeferenced or ortho-rectified when you receive it?
No
Sight Line / Line-of-Sight
Line connecting viewpoint and target in a viewshed analysis
In cartography, when surface sample values are collected by direct measurement, how are the values of the area between these measured locations assigned?
Linear interpolation from the nearest nodes
Why is map algebra important to GIS?
Major GIS systems (including ERDAS Imagine and ArcGIS) use map algebra concepts
Spatiotemporal Representation
Making spatial and temporal (time-related) interactions and processes visible
What is another term for spatial intersection?
Map overlay
Lambert Conformal Conic
Map projection on which SPC system is based
What is a CHLOROPETH map?
Map where areas are shaded according to a prearranged key, each shading or color type representing a range of values
Stochastic Model
Mathematical model that considers the presence of randomness in one or more of its parameters or variables.
Topology (general)
Mathematical study used to define spatial relationships [Mathematical study of the properties of shape and how the change or stay the same under transformations (like bending, twisting, stretching)]
What are the maximum and recommended number of classes to use when categorizing geospatial data?
Maximum: up to 7 classes Recommended: 5
Data Completeness
Measure of totality of features
How do GPS systems calculate distance?
Measure time interval between transmission and reception of satellite signal
What is another term for "Resolution"?
Measurement scale
Measurement (techniques of spatial analysis)
Measures proprieties such as distance, length, area, and shape
What is a LAYER in simplest terms?
Mechanism to display geographic datasets
What is the NGDA Climate and Weather Theme?
Meteorological conditions, including temperature, precipitation, and wind
Change over Time (Change Detection)
Method of understanding how a given area has changed between two or more time periods.
Geospatial Technology Competency Model (GTCM)
Model of the current knowledge and skills needed by geospatial technology professionals.
How were the locations of the lines that appear on current U.S. Geological Survey topographic maps originally documented?
Most of the lines were originally engraved by hand and those engravings have since been digitized
How is spatial reference determined when the input doesn't have an input dataset (eg, Create Feature Class and Create Feature Dataset)?
Must choose a coordinate system during set-up so the remainder of the spatial reference properties (such as XY resolution and tolerance) can be calculated by the tool.
What are the three most commonly used datums in North America?
NAD 1927 using the Clarke 1866 spheroid NAD 1983 GRS 1980 spheroid WGS 1984 using the WGS 1984 spheroid
Which two datums will have identical coordinates for the same point in most applications?
NAD 1983 and WGS 1984
NAPP
National Aerial Photography Program
NAIP
National Agriculture Imagery Program
NDOP
National Digital Orthophoto Program
How do CHLOROPLETH and PROPORTIONAL SYMBOL maps differ regarding the size of the area associated with the variable?
Proportional symbol maps are not dependent on the size of the area associated with the variable. e.g. on a proportional symbol map of Europe, tiny Liechtenstein would have the same visual importance as Spain if their unemployment values were the same.
What is a solution to the issue with choropleth maps that they are often not suitable for showing total values?
Proportional symbols overlays
What is the difference of quantitative and qualitative data?
Quantitative data is numerical (at least ordinal, but could be metric), while qualitative data is non-numerical or numerical that doesn't have quantitative meaning (nominal)
Query
Question addressed to a database through a DBMS
If you have a feature represented in raster format and vector format, which one is more efficient format to use when trying to determine slope (gradient), and why?
Raster -The slope of one raster grid cell may be calculated by comparing its elevation to the elevations of the cells that surround it.
What are the single most commonly used surface models in ArcGIS?
Rasters
Should dot maps be used to represent raw data, prearranged data, or percentages
Raw data
Temporal Resolution
Refers to the time between images High temporal resolution means capable of resolving very small units of time
What is the most common source of radiation measured by passive sensors?
Reflected sunlight
What is the purpose of the Geospatial Technology Competency Model?
Reflects the knowledge and skills needed by today's geospatial technology professionals.
What are the time intervals that can represent a point in time?
Regular or irregular interval
What is Classification?
Representing members of a group by the same symbol
Optimization (techniques of spatial analysis)
Results in designs that achieve user-defined objectives (e.g. search for best location)
Simple query (techniques of spatial analysis)
Returns results already existing in database
What is the fifth step in the field collection process?
Review sample field collection and adjust the data being collected or the method of data collection
What is the NGDA Cadastre Theme?
Rights and interests in real property for taxation purposes
Describe a real-world situation in which digitized mapping has improved a process in the transportation industry
Road designers combine aerial imagery and digital mapping systems to estimate project costs by calculating the volumes of rock that need to be excavated from hillsides and filled into low areas.
How would describe a "road" in generic vector terms?
Roads are an example of linear entities
Who is considered the "Father of GIS"
Roger Tomlinson -first used the term "Geographic Information System" in his paper "A Geographic Information System for Regional Planning" (1960s)
For using temporal data in ArcGIS, you should store the time values associated with individual features in this format:
Row
What is the relationship between SDTs and SQLs?
SDTs are an essential component of SQL
What is the most commonly used DML command?
SELECT
How would you word a query to result in every combination of rows in from two tables called "T1" and "T2"?
SELECT * FROM T1, T2; will result in every combination of T1 and T2 rows e.g., if T1 has 3 rows and T2 has 5 rows, then 15 rows will result
How would you word a query to result in all the elements of all the rows where the value of column C1 is '1' in a table called "T"?
SELECT * from T where C1 = 1;
How would you word a query to return all the elements of all the rows of a table called "T"?
SELECT * from T;
How would you word a query to return all the elements from column C1 in a table called "T"?
SELECT C1 from T;
What is the NGDA Water - Oceans & Coasts Theme?
Salt water bodies features and characteristics *tides *tidal waves *coastal information *reefs *shorelines
What is the formula to calculate GSD?
Scale of photograph /DPI / Inches = GSD (ft)
Remote Sensing
Scanning of the earth by satellite or high-flying aircraft
What are the two translation issues that Geographic data translation software must address
Syntactic and semantic
What is the benefit of Continuous deployment and integration?
Security fixes deployed constantly (daily or hourly)
What is a classification schema (or key)?
Set of criteria based on feature's attributes used to decide which individuals go into each class
How many steps are there in the field collection process?
Seven
What type of data are ISARITHMIC (aka ISOPLETH) maps ideal for?
Showing gradual change over space
What is the easiest way to show spatial change over time on a static map?
Side by side maps each showing a point in time
What is a SNR mask?
Signal to Noise Ratio
Partial sill
Sill minus nugget in a semivariogram
Model (simplified)
Simplified static representation
Is generalization better used for larger or smaller scaled maps?
Smaller, because they show less detail anyway.
Resolution
Smallest measurement unit for an object, such as pixels for remote sensing
Name the most general defining feature of Spatial Data Types
Spatial Data Types play a large part in successful design of spatial data models
Object-based spatial database
Spatial database that stores the location as objects, as opposed to fields
Why are spatial data queries different than non-spatial data queries?
Spatial queries require knowledge of locations as well as attributes
How is spatial reference determined when the input is a list of datasets (e.g. the Intersect tool)?
Spatial reference of the first input dataset will be used.
How is spatial reference determined when the input is a layer in a display?
Spatial reference of the layer's data source is used.
How is spatial reference determined for outputs inside a feature dataset?
Spatial reference properties of feature dataset are used -If the output is stand-alone geodataset (not inside a feature dataset), the spatial reference properties are the same as the input geodataset's.
Spatial Data Types
Special Data Types needed to model geometry and to represent geometric data in database systems
GIS Modeling
Specific type of spatial modeling that looks for patterns and spatial relationships
A spreadsheet is not a DBMS. And, by the same token, a mapping system is not a GIS. Explain.
Spreadsheets were not engineered to provide secure means of managing and analyzing large databases that consist of many related files, each of which is the responsibility of a different part of an organization.
What is SPS?
Standard Positioning Service -one of the two original services provided when GPS first developed -positioning and timing service available to all GPS users -Broadcasted on L1 frequency -contains a coarse acquisition (C/A) code and a navigation data message.
What is the seventh step in the field collection process?
Start the field collection for all assets
Hypothesis testing (techniques of spatial analysis)
Statistical methods are used to reason from a sample to a larger population
SQL
Structured Query Language: a standardized language adopted by DBMS software vendors and used to pose queries
Geospatial topology
Study of determining and preserving the relationships between shapes in a vector data model
Planimetrics
Study of plane measurements, including angles, distances, and areas
What is the NGDA Geodetic Control Theme?
Survey control points or other related data sets which are accurately tied to the NSRS
What is a representative sample in the world of digital geographic data?
The Earth is too big for any one geographic data set to represent every possible location; the number of unique locations is too high. -It's like how opinion data is measured by polls rather than asking every single person in the larger group
What is ISO?
The International Organization for Standardization (ISO) is a worldwide federation of national standards bodies.
What is the general rule for scaling proportional symbols?
The area, rather than linear proportions like radius or length of a side, should be the scaled parameter. -e.g. if there are four times as many businesses in City A than City B, the area of the symbol should be four times greater for City A. --If the symbol choice is a circle, the radius of the City A symbol should thus be only twice as great (since area scales with the square of the radius).
What is the major difference between a local datum and a geocentric datum?
The coordinate system origin of a local datum is not at the center of the earth
What is the determining factor for where a feature falls on the continuous-to-discrete spectrum?
The ease in defining the feature's boundaries.
What is the DESIGN PHASE of systems architecture design?
The following must be identified: -Data acquisition -Network communication capacity -Hardware and software procurement -Infrastructure requirements -Software development
Physical distance
The measured distance between two points or cells
Geodesy
The science of measuring the shape of Earth and locating points on its surface.
Sill
The value that the semivariogram model attains at the range (on the y-axis)
Nugget
Theoretically, at zero separation distance (lag = 0), the semivariogram value is zero. However, at an infinitesimally small separation distance, the semivariogram often exhibits some value greater than zero. For example, if the semivariogram model intercepts the y-axis at 2, then the nugget is 2.
What is the main goal of creating both vector and raster datasets?
They allow us to caricature the Earth's surface with a limited number of locations.
What is the relationship between pixel size and DPI?
They are inversely proportional
Why are ISARITHMIC (aka ISOPLETH) maps better for showing gradual change over space than CHLOROPETH maps are?
They avoid the abrupt changes that boundary lines produce on choropleth maps.
How do interpolation tools work (surface development)?
They create a continuous surface from discrete samples with measured values *e.g. elevation *e.g. chemical concentration
How do digital airborne imaging systems produce raster data?
They scan the Earth's surface pixel by pixel and row by row.
Why are newer spheroids more accurate than those developed in the 19th and early 20th centuries?
They were developed from satellite measurements
What is a common reason why a map user would need to see a graphical representation of time on their map?
To understand how a given area has changed over specified period (eg how natural features in an area have changed)
Coverage
Topological vector data format used in Esri products
Equal (topological relation)
Topologies of both objects are exactly the same a = b
What is vectorization?
Transforming rasters in vectors.
TIN
Triangular irregular networks -Vector-based surfaces used to represent surface morphology -constructed by triangulating a set of vertices (points)
What basic data representation strategy is used to store data in CAD?
Vector
In a real-world analogy, describe the two sampling strategies of Vectors and Rasters?
Vector approach is like creating a picture of a landscape with shards of stained glass cut to various shapes and sizes. The raster approach is like creating a mosaic with tiles of uniform size.
Give two examples of sampling strategies for digital geographic data
Vectors and rasters
What are the two predominant representation strategies for digital mapping?
Vectors and rasters
What spheroid does WGS 84 use?
WGS 1984 spheroid
Which datum are GPS receivers designed to collect GPS positions with?
WGS84 datum
What is spatialtemporal visualization?
Ways to illustrate changes in an area over time on a map
Metadata question: _____________ was the data collected?
When
Why can the age of data be an obvious source of error?
When data sources are too old, some, or a big part, of the information base may have changed
For non-Esri spatial data types, when are types and functions installed?
When spatial component is installed into DBMS
When would temporal time data be stored in a two attribute fields?
When time values represent duration of time -Start time, end time
What is a real world example of how you would visually know that a dataset isn't topologically valid?
When you look at a shapefile and there are lots of little slivers (that shouldn't be there) between the polygons. -This is a problem because, if there are slivers where there shouldn't be, when you calculate the geometry of those polygons, the resulting area wont be correct relative to what the area actually is in real life
When would temporal time data be stored in a single attribute?
When you're collecting data at particular times -e.g. stream flow data (regular intervals), lightning or earthquake data (irregular intervals)
What does viewshed analysis help predict?
Which parts of a landscape will be visible or hidden from view from a specific perspective
What is the main drawback of generalizing a map or dataset?
Will cause data to be less accurate
Describe the main difference between spatial statistics and aspatial (traditional) statistics
With spatial statistics, space and spatial relationships are integrated directly into the mathematics
What does WGS stand for?
World Geodetic System
What would be a solid pre-programming process before starting an automated process where you had new temperature snapshots available daily that needed to be used to update an online map daily?
Write out the specific steps to take to complete by hand: -get the files -convert them -update the map, all by hand. -begin to look for scripting tools
What is another term for a coordinate system?
map projections
What is hypsometry?
measurement of land elevation relative to sea level
What is the simplest definition of a Layer?
mechanism to display geographic dataset
Describe the trend of Computing Capacity for Geospatial Research, Apps
more easily and quickly access and contribute to geospatial data, tools, and services.
What is another term for a continuous raster?
non-discrete or surface data
Describe POSTSCRIPT (as a vector format)
page definition language to export or print a map
What is a spatial reference?
parameters that define the coordinate system and other spatial properties for dataset
What is a PSD file?
photoshop file for editing
What is the NGDA Transportation Theme?
physical and non- physical ways of conveying persons and/or goods
Describe GPS as a data collection method
using a GPS receiver to receive signals from GPS satellites to calculate the current position and time
Manhattan Distance
vertical plus horizontal distance [abs(x1‐x2) + abs(y1‐y2)]
What is the NGDA Elevation Theme?
vertical position of the earth surface and other landscape or bathymetric features
Describe deceptive mapping
when maps are distorted for propaganda, military protection, or out of ignorance
Internal Direction
where an object is located inside the reference object
What are the two methods for performing overlay analysis?
—feature overlay (overlaying points, lines, or polygons) -raster overlay
What is the NGDA Real Property Theme?
real property entities, e.g.: -unimproved land -buildings and structures -site improvements -underlying land
Scale
relative proportions between objects in the real world and their representations on a map
In the world of digital geographic data, what concept would be considered the equivalent of a "poll"?
representative samples of locations
What is map algebra?
set of primitive operations that allows two or more raster layers of similar dimensions to produce a new raster layer using algebraic operations such as addition, subtraction etc.
What are CONTOURS in the context of cartography and SURFACES?
sets of lines of equal value across a surface
Geoid
shape that the earth's surface would take under the influence of the gravity and rotation of Earth alone, if other influences such as winds and tides were absent
How is spatial reference determined for stand-alone geodataset (not inside a feature dataset)?
spatial reference properties are the same as the input geodataset's.
How does Topo to Raster interpolation work (surface development)?
specialized tool for creating hydrologically correct raster surfaces from vector data of terrain (e..g. elevation points, contour lines).
Define semiotics
study of signs and symbols and their use or interpretation
Boolean
symbolically represents relationships (such as those implied by the logical operators AND, OR, and NOT) between entities
Data
symbols that represent measurements of phenomena
What happens at the datelines when data is projected in a projected coordinate system?
the +/-180° lines are inside
What is the NSDI?
the National Spatial Data Infrastructure
Data quality
the ability of data to be reliable enough to serve a specific purpose.
Though modeling itself can be considered a form of representation, what is it more likely assumed to be?
the data-handling step prior to subsequent representation
What is a Database Administrator
the person responsible for coordinating, controlling, and managing the database
Raster resolution (general)
the potential detail provided by the imagery
