DeLorme Street Atlas USA 2009, User Manual

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Getting Started
15
Easting
The measure of a position relative to the x-axis (horizontal) of a grid system.
Elevation Gain
The difference in elevation from the start of the profile to the end of the profile.
Ephemeris
Data that indicates the position and status of satellites.
EST
Eastern Standard Time
GMT
Greenwich Mean Time; used as the standard of time throughout the world.
GPS
Global Positioning System; a "constellation" of orbiting satellites used to calculate a
precise position on or near the earth's surface.
Grade
Actually percent grade, rise over run (100 x (rise/run)). For example, 6 means that
for every 100 ft, you gain 6 ft in elevation.
HDOP
The measure of how much the geometry of the satellites affects the horizontal
position estimate.
Heading
Azimuth of the longitudinal axis of an aircraft or ship. Heading may differ from
direction of travel when flying or boating due to currents in the air or water.
Initialize
To set to a starting position, as in obtaining initial coordinates for a GPS receiver.
Latitude
The measure of a position on the earth's surface north or south of the equator in
degrees, minutes, and seconds. Defined as the angle from the equator's horizontal
plane perpendicular to the polar axis. All lines of latitude are parallel and are often
referred to as parallels.
Log
A record of the speed, direction, and route of travel as obtained via GPS.