ANSWERS 100% VERIFIED
Data exploration - ANSWER-Data-centered query and analysis
Dynamic Segmentations - ANSWER-A data model that allows the use of linearly
measured data on a coordinate system
Georelational data model - ANSWER-A vector data model that uses a split system to
store geometries and attributes
GeoSpatial data - ANSWER-Data that describes both the locations and characteristics
of spatial features on the earth surface
Object-based data model - ANSWER-A data model that uses objects to organize spatial
data and stores geometries and attributes in a single system
Raster data model - ANSWER-A data model that uses a grid and cells to represent the
spatial variation of a feature
Relational Database - ANSWER-A collection of tables in which tables are connected to
one another by keys
Topology - ANSWER-A subfield of mathematics that when applied to GIS, ensures that
the spatial relationships between features are expressed explicitly
Triangulated irregular network (TIN) - ANSWER-Composite vector data that
approximate the terrain with a set of nonoverlapping triangles
Vector data model - ANSWER-A spatial data model that uses points and their x y
coordinates to construct spatial features of points, lines and polygons
Azimuthal Projection - ANSWER-One type of map projection that retains certain
accurate directions. Azimuthal also refers to one type of map projection that uses a
plane as the projection surface
Datum - ANSWER-The basis for calculating the geographic coordinates of a location.
An ellipsoid is a required input to the derivation of a datum
Datum shift - ANSWER-A change from one datum to another, such as from NAD27 to
NAD83, which can result in substantial horizontal shifts of point positions
,Decimal degrees (DD) system - ANSWER-A measurement system for long and lat
values such as 42.5
Degrees minutes seconds - ANSWER-A measurement system for long and lat values
such as 42 30' 00", in which 1 degree equals 60 minutes and 1 minute equals 60
seconds
Central lines - ANSWER-The central parallel and the central meridian. Together, they
define the center or the origin of a map projection
Clarke 1866 - ANSWER-A ground-measured ellipsoid, which is the basis for the North
American Datum of 1927 (NAD27)
Conformal projection - ANSWER-One type of map projection that preserves local
shapes
Conic Projection - ANSWER-One type of map projection that uses a cone as the
projection surface
Cylindrical Projection - ANSWER-One type of map projection that uses a cylinder as the
projection surface
Ellipsoid - ANSWER-A model that approximates the earth, ALSO called spheroid
Reference globe - ANSWER-A reduced model of the earth from which map projections
are made. Also called a nominal or generating globe
Reprojection - ANSWER-Projection of spatial data from one projected coordinate
system to another
Scale factor - ANSWER-Ratio of the local scale to the scale of the reference globe. The
scale factor is 1.0 along a standard line.
Spheroid - ANSWER-A model that approximates the earth. Also called ellipsoid
Equidistant projection - ANSWER-One type of map projection that represents areas in
correct relative size
False easting - ANSWER-A value applied to the origin of a coordinate system to change
the x-coordinate readings
False northing - ANSWER-A value applied to the origin of a coordinate system to
change the x-coordinate readings
, Geographic Coordinate data base (GCDB) - ANSWER-A Database developed by the
US bro of Land Managment (BLM) to include long and lat values and other descriptive
information for section corners and monuments recorded in the PLSS
Geographic Coordinate System - ANSWER-A location reference system for spatial
features on the Earths surface
GRS80 - ANSWER-A satellite-determined ellipsoid for the Geodetic Reference System
Lambert Conformal conic projection - ANSWER-A common map projection, which is the
basis for the SPC system for many states
Latitude - ANSWER-The angle north or south of the equatorial plane
Longitude - ANSWER-The angle east or west from the prime meridian
Map Projection - ANSWER-A systematic arrangement of parallels and meridians on a
plane surface
Meridians - ANSWER-Lines of longitude that measure locations in the E-W direction on
the geographic coordinate system
NAD27 - ANSWER-North American Datum of 1927 which is based on the clarke 1866
ellipsoid
NAD83 - ANSWER-North American Datum of 1983 which is based on the GRS80
ellipsoid and has its origin at the center of the ellipsoid
Parallels - ANSWER-Lines of latitude that measure locations in the N-S direction on the
geographic coordinate system
Principal scale - ANSWER-Same as the scale of the reference globe
Projected coordinate system - ANSWER-A plane coordinate system that is based on a
map projection
Projection - ANSWER-The system used to transfer locations from Earth's surface to a
flat map.
Public Land Survey System (PLSS) - ANSWER-A land partitioning system used in the
United States
Standard line - ANSWER-Line of tangency between the projection surface and the
reference globe A standard line has no projection distortion and has the same scale as
that of the reference globe