C NMEA-0183 Messages
114 DSM 132/132RS Receiver User Guide
C.12GST (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
TableC.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
1UTC time of GGA fix
2RMS 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