Ag Leader GPS 5100 User Guide - Manual (Page 21)

GPS 5100 Receiver User Guide 1 5
Overview 2
27.1
Coordinate systems
Geographic data obtained from different sources must be referenced to
the same datum, ellipsoid, and coordinate format. Different formats
provide different coordinate values for any geographic location. In
North America, the datums NAD-27 and NAD-83 are commonly used
in Agricultural mapping applications.
The GPS 5100 receiver outputs position coordinates in several datums
and ellipsoids depending on the GPS positioning method being used.
See Table 2.6.
For more information, go to the National Geodetic Survey website at
www.ngs.noaa.gov/faq.shtml#WhatDatum
Table 2.6 DGPS coordinate systems
GPS positioning method Datum Ellipsoid
None – Autonomous mode WGS-84
1
WGS-84
OmniSTAR VBS North American Beams NAD-83 2 GRS-80
OmniSTAR VBS Rest of World Beams ITRF
3
GRS-80
OmniSTAR HP ITRF 2000 ITRF 2000
WAAS Beams WGS-84 WGS-84
RTK WGS-84 WGS-84
1 World Geodetic System (WGS) 1984. Datum and ellipsoid.
2 North American Datum (NAD) 1983. Equivalent to WGS-84 in North America.
3 International Terrestrial Reference Frame (ITRF). Contact the DGPS provider for details.