Standard NMEA: GNSS pseudorange error statistics.
NMEA-GP-GST_GNSS for combined (average) output from both receivers
The time is the average between GNSS1 and GNSS2.
The RMS value is computed over all the used measurements among both receivers
The standard deviation values are computed from the mean of the covariance matrices in ECEF at the mean position between GNSS1 and GNSS2
NMEA-GP-GST_GNSS1 for output from GNSS 1 receiver
This is the standard NMEA GST for GNSS1.
NMEA-GP-GST_GNSS2 for output from GNSS 2 receiver
This is the standard NMEA GST for GNSS2.
NMEA-GP-GST_FUSION for output from Fusion
The time and STD data is from the Fusion solution.
These messages does not contain any information that would let one tell them apart. Do not enable more than one of these in the same port.
This message is according to NMEA 0183 v4.11 (and erratas).
It uses the “GP” talker ID even though the navigation solution is multi-GNSS.
Example messages
Normal:
$GPGST,GPGST,114319.60,5.2,0.4,0.3,62.5,0.3,0.4,1.1*68rn
With non-standard high-precision fields:
| # | Field | Format | Unit | Nullable | Example | Description |
|---|---|---|---|---|---|---|
| 1 | time |
|
- |
Y |
|
UTC time (hours, minutes and seconds) |
| 2 | rms_range |
|
- |
Y |
… |
RMS value of the standard deviation of the range inputs to the navigation process |
| 3 | std_major |
|
m |
Y |
… |
Standard deviation of semi-major axis of error ellipse |
| 4 | std_minor |
|
m |
Y |
… |
Standard deviation of semi-minor axis of error ellipse |
| 5 | angle_major |
|
deg |
Y |
… |
Angle of semi-major axis of error ellipse from true North |
| 6 | std_lat |
|
m |
Y |
… |
Standard deviation of latitude error |
| 7 | std_lon |
|
m |
Y |
… |
Standard deviation of longitude error |
| 8 | std_alt |
|
m |
Y |
… |
Standard deviation of altitude error |