Trimble Outdoors 132 - Manual (Page 114)

C NMEA-0183 Messages
11 4 DSM 132/132RS Receiver User Guide
C.12
GST (GPS PRN)
The GST message is used to support Receiver Autonomous Integrity
Monitoring ( RAIM ).
The GST message structure is:
$GPGST,220320.0,1.3,0.8,0.5,166.1,0.8,0.5,1.6,*4F
Table C.10 describes these fields.
Note – Because the contents of this NMEA message do not change
significantly during a one-second interval, the receiver outputs this
message at a maximum rate of 1 Hz.
Table C.10 GST message fields
Field Description
1 UTC time of GGA fix
2 RMS value of the standard deviation of the range inputs to the
navigation process (range inputs include pseudoranges and DGPS
corrections)
3 Standard deviation of semi-major axis of error ellipse, in meters
4 Standard deviation of semi-minor axis of error ellipse, in meters
5 Orientation of semi-major axis of error ellipse, in degrees from true
north
6 Standard deviation of latitude error, in meters
7 Standard deviation of longitude error, in meters
8 Standard deviation of altitude error, in meters