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NAVIOR-24S
™
Appendix D
NMEA 0183 Communication Interface
181
NAVIOR-24S ™
Revision
V1.00 20.05.2008
GSA - GNSS DOP and Active Satellites
The GSA messages indicates the GPS receiver operating mode and lists the satellites used for
navigation and the DOP values of the position solution.
Format:
$GPGSA, a, x, xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx, x.x, x.x, x.x <CR><LF>
Field
Format
a Mode:
M = Manual, forced to operate in 2D or 3D mode
A = Automatic, allowed automatically switch 2D/3D
x Current
Mode:
1 = fix not available
2 = 2D
3 = 3D
xx
(12 fields)
PRN numbers of the satellites used in the position solution (null for unused
fields).
x.x
Position dilution of precision (PDOP)
x.x
Horizontal dilution of precision (HDOP)
x.x
Vertical dilution of precision (VDOP)
<CR><LF>
2 ASCII control characters
Notes that GPS satellites are identified by their PRN, which range from 1 up to 32. The WAAS
system has numbers 33-64 to identify its satellites. The numbers 65-95 are used for GLONASS
satellites (64 + satellite slot number)