Geodesy and Geographic Information Systems: Terminology and Concepts, Quizzes of Geography

Download Geodesy and Geographic Information Systems: Terminology and Concepts and more Quizzes Geography in PDF only on Docsity! TERM 1 Horizontal datums DEFINITION 1 use of planar surface for projecting ellipsoidal locations TERM 2 Vertical datums (2) DEFINITION 2 elevation orthometric height the height above mean sea level (geoid) ellipsoidal height the height above the references ellipsoid TERM 3 2 common vertical datums DEFINITION 3 National Geographic Vertical Datum of 1929 (NGVD29)North American Vertical Datum of 1988 (NAVD88) TERM 4 Models of the Earth's surface DEFINITION 4 ellipsoid is fitted to the Earth's geoidal representation TERM 5 What does GPS tell us DEFINITION 5 it tells us how far away we are from the ellipsoid TERM 6 Map scale (3) DEFINITION 6 certain distance on map represents some distance on the ground2 types: representative fraction- 1:24,000 scale bar- graphical representation TERM 7 Map types (3) DEFINITION 7 equal area same area on ground conformal relative local angles around every point on map is correct azimuthal projection directions of all points on map are correct with respect to center (direction) NO MAP CAN BE BOTH EQUAL AREA AND CONFORMAL TERM 8 Geometric figures used for map projections (3) DEFINITION 8 plane azimuthal projection intersecting figure cone equal area and conformal intersecting figure cylinder rotated figure TERM 9 Standard points and lines (4) DEFINITION 9 is where the reference map figure is tangent to the Earth's surfaceplane-tangent at one point or tangent along a linecone/cylinder- tangent along two linesscale is most accurate for the map area closest to the Earth's surface TERM 10 State plane coordinate system (5) DEFINITION 10 unique for each stateparameters are specific for each statelambert conic is good for longer east-to-west extentsUTM is good for longer north-to-south extentssome states use multiple projections TERM 21 Topology DEFINITION 21 the property that describes adjacency and connectivity of features TERM 22 Node DEFINITION 22 the end of an arc, has topological significance TERM 23 Common ESRI vendor data structures (4) DEFINITION 23 shape filecoveragepersonal geodatabasefile geodatabase TERM 24 3 major approaches to collecting geographic data DEFINITION 24 capture of data remotely (remote sensing)- primary data captureconversion of existing hardcopy maps to digital maps- data conversioncapture of data in the field- primary data capture TERM 25 Executive order 12906 (3) DEFINITION 25 resulted in a clear and dramatic shift in how Federal agencies collect and distribute geospatial datagoals: record spatial patterns of features attribute features established: the federal geographic data committee national geospatial data clearinghouse standardized documentation of data public access to geospatial data TERM 26 Primary data capture (2) DEFINITION 26 the process of abstracting and recording the geographic position and attributes of features from their native sourcecommon methods surveying remote sensing TERM 27 Data conversion (2) DEFINITION 27 the process of converting existing mapped geographic data into a digital formatcommon methods historic topological maps land parcel maps TERM 28 Value added geographic data DEFINITION 28 refers to the digital geographic data that has been edited to make a more useful dataset corrections or additions TERM 29 Federal geographic data committee DEFINITION 29 interagency committee that promotes the coordinated development, use, sharing, and dissemination of geospatial data on a national basis TERM 30 FGDC clearinghouse DEFINITION 30 house for searching datadoes not store the data, but stores the locations of where the data exists and how the user may access itwhen searching use who what where TERM 31 Future collection sources (4) DEFINITION 31 autonomous location/tracking of features cell phone radio frequencies receivers geotagged pictures, text messages, or videos volunteered geographic information (VGI) TERM 32 What has changed in the dissemination of geospatial data since executive order 12906 (2) DEFINITION 32 1990s-2000s data obtained and placed on desktop PC 2010-present data obtained through cloud computing