Appendix A-Glossary - Garmin GPS 45 Owner's Manual & Reference

Appendix A
Glossary
Almanac Data—Satellite constellation information (including location and health of
satellites) that is transmitted to your receiver from every GPS satellite.
Almanac data must be acquired before GPS navigation can begin.
Bearing—The compass direction from your position to a destination.
Course Made Good (CMG)—The bearing from the 'active from' position (your starting
Crosstrack Error (XTE)—The distance you are off a desired course in either direction.
Desired Track (DTK)—The compass course between the 'from' and 'to' waypoints.
Differential GPS (DGPS)—An extension of the GPS system that uses land-based
radio beacons to transmit position corrections to GPS receivers.
Estimated Time of Arrival (ETA)—The time of day of your arrival at a destination.
Estimated Time Enroute (ETE)—The time left to your destination at your present speed.
Grid—A coordinate system that projects the earth on a flat surface, using square zones for
position measurements.
Ground Speed—The velocity you are travelling relative to a ground position.
Latitude—A north/south measurement of position perpendicular to the earth's polar axis.
Longitude—An east/west measurement of position in relation to the Prime Meridian, an
imaginary circle that passes through the north and south poles.
Position—An exact, unique location based on a geographic coordinate system.
Track (TRK)—The direction of movement relative to a ground position.
Universal Transverse Mercator- (UTM)— A grid coordinate system that projects
global sections onto a flat surface to measure position in specific zones.
Velocity Made Good (VMG)—The speed you are closing in on a destination along a
desired course.
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point) to your present position.