Chapter 5 - Understanding Position Coordinates
961 Operations and Reference Manual Rev. D
Page 5-3
GPS satellite status screen
The
GPS SATELLITE STATUS
screen shows the received Sig-
nal-to-Noise Ratio (SNR) for each satellite (up to 12), and a map
indicating where the satellites are now located in the sky. Sat-
ellites are identified by their pseudorandom number (PRN), a
two-digit number assigned by the U.S. government. The center
of the satellite map represents the center of the sky, and the
outer ring is the horizon. The view is looking down from
above, with East to your right and West to your left.
Also displayed on the screen is the following GPS data:
•
ACCURACY
•
HDOP
(horizontal dilution of precision)
Accuracy is the estimated accuracy of the GPS system to be
expected at the current time. Your position readings should be
more accurate than this estimate 95 percent of the time.
HDOP is a technical measure of how good the satellite pattern
is in the sky for fix-taking purposes. HDOP depends on how
many operational satellites are in view and where they’re cur-
rently located. HDOP is calculated from the satellites’ current
positions, not on actual received signals, and doesn’t consider
atmospheric conditions, Selective Availability, and signal inter-
Содержание 961X
Страница 1: ...961 961 GPS Chart Navigator Operations and Reference Manual P N GM1700 Revision D X XD ...
Страница 8: ...Page viii 961 Operations and Reference Manual Rev D ...
Страница 10: ...Page x 961 Operations and Reference Manual Rev D ...
Страница 58: ...Chapter 2 Introducing the 961 Page 2 16 961 Operations and Reference Manual Rev D ...
Страница 140: ...Chapter 5 Understanding Position Coordinates Page 5 12 961 Operations and Reference Manual Rev D ...
Страница 172: ...Chapter 7 Creating Avoidance Points Page 7 16 961 Operations and Reference Manual Rev D ...
Страница 198: ...Chapter 8 Creating Routes Page 8 26 961 Operations and Reference Manual Rev D ...
Страница 262: ...Chapter 12 Alarms TideTrack and Currents Page 12 16 961 Operations and Reference Manual Rev D ...
Страница 348: ...Chapter 14 Service and Maintenance Functions Page 14 20 961 Operations and Reference Manual Rev D ...
Страница 374: ...Index Page I 12 961 Operations and Reference Manual Rev D ...