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Geographic Coordinate Systems

Defenitions at: www.fgdl.org/tutorials/howto_reproject/Definitions.html
Preferred by State Governmenets:
Geographic (Latitude/Longitude or Decimal Degrees)
Universal Transverse Mercator (UTM)
State Plane Coordinate System (SPCS)
Other
Albers Equal-Area Conic Projection - Used by the USGS in their 1970 National Atlas.

Lambert Azimuthal Equal-Area
Lambert Conformal Conic

Glossary

DEM
Digital Elevation Model (USGS)
DGPS
Differential GPS 3-5 m. accuracy
DLG
Digital Line Graph
DOQ
Digital Orthophoto Quadrangles
DQQ
Digital Quarter Quadrangle
DTM
Digital Terrain Model (USGS)
DXF®
is the Drawing eXchange Format from AutoCAD
GIS
- Geographic Information System - A system of hardware, software, and procedures for drawing and analyzing maps and data referenced by spatial or geographic coordinates. Becoming a standard for government projects.
GPS
Global Positioning System (Tutorial at trimble.com)
HPGN
- High Precision GPS Network High Accuracy Reference Network (HARN) or High Precision Geodetic Network (HPGN) - HARN and HPGN are both names for the same project that is focused on readjusting the NAD83 datum to a higher level of accuracy state by state.
NAD27
North American Datum 1927 - State Plane Feet -
NAD83
North American Datum 1983 - State Plane Meters -
NAPP
National Aerial Photography Program (USGS)
NDOP
National Digital Orthophoto Program (USGS)
NGS
- National Geodetic Survey - Defines and manages a national coordinate system. This network, the National Spatial Reference System (NSRS), provides the foundation for transportation and communication; mapping and charting;
NADCON
- the federal standard for NAD27 to NAD83 datum transformations within the United States.

NADCON conversions between datums are approximate values based on models of real data. A regular grid of control points whose datum shifts are known is used to estimate the shift at other locations. A minimum curvature-derived surface based upon the National Geodetic Reference System determines the transformation of points and introduces approximately 0.15 meters uncertainty (at the 67% confidence level) within the coterminous United States.4 The accepted national standard, NADCON is the fastest, simplest, and most accurate datum transformation for mapping at scales of 1:200 and smaller.

NADCON only converts geographic (latitude and longitude) coordinates. The method cannot be applied directly to projected coordinates, such as State Plane.

See ftp.ngs.noaa.gov/pub/pcsoft/nadcon/readme.txt
NADCON software is available at: http://www.ngs.noaa.gov/PC_PROD.

NOAA
- National Oceanic & Atmospheric Administration
NSRS
National Spatial Reference System
NRCS
- U.S. Natural Resource and Conservation Service (gis.itc.nrcs.usda.gov)
SPCS
State Plane Coordinate System
SDTS
Spatial Data Transfer Standard
TVP
Topological Vector Profile
USGS
- U.S. Geological Survey - Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment.
UTM
- Universal Transverse Mercator
WAAS
Wide area augmentation system (or sites) for GPS (< 3m. accuracy)
WGS 84
World Geodetic System - Used by GPS systems. Adopted from NAD 83. For all practical purposes there is no difference between WGS 84 and NAD 83.

Map Symbols

Areview symbols at http://www.mapsymbols.com
Maps

See Also:

Nautical Charting & Navigation at NOAA
Location and Mapping in smart phones and tablets

Sources:
North Carolina GIS Technical Advisory Committee Position Paper


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last updated 12 May 2004