II Morrow Inc. 920 GPS User Manual
Page 93
NMEA (National Marine Electronics Association):
The group responsible for defining and maintaining
serial data format standards for marine electronic
navigation devices.
PDOP (Position Dilution of Precision): A merit value
for the calculated position based on the geometrical
configuration of the satellites used; 3 is considered
good, greater than 7 is considered poor.
Radial: Any of the 360 magnetic courses from a VOR
or similar navigational aid, starting with zero at the
magnetic
north
and
increasing
clockwise
(90
degrees
=
East;
180
degrees
=
South;
270 degrees = West; 360 or zero degrees = North).
RNG (Range): The distance from the present position
to a destination waypoint.
SA
(Selective
Availability):
The
degradation
of
accuracy of GPS position fix data by the United States
Department of Defense for civilian use.
Second: 1/60th of a minute of a circle.
G
6