Trimble Outdoors 132 - Manual (Page 113)

DSM 132/132RS Receiver User Guide 11 3
NMEA-0183 Messages C
C.11
GSA (GPS DOP and Active Satellites)
The GSA message identifies the GPS position fix mode, the SVs used
for navigation, and the Dilution of Precision values.
The GSA message structure is:
$GPGSA,A,3,19,28,14,18,27,22,31,29,,,,,
1.7,1.0,1.3*35
Table C.9 describes these fields.
Table C.9 GSA message fields
Field Description
1 Mode
M: Manual, forced to operate in 2D or 3D
A: Automatic, 3D/2D
2 Mode
1: Fix not available
2: 2D
3: 3D
3–14 IDs of SVs used in position fix (null for unused fields)
15 PDOP
16 HDOP
17 VDOP