Garmin GPS 90 - Manual (Page 80)

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 point) to your present position.
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’ way-
points.
D i ff e rential 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 desti-
nation.
Estimated Time Enroute (ETE)—The time left to your destination at your pre-
sent 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.
L o n g i t u d e —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.
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Appendix E
Glossary
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