APPENDIX
AP-12
DTM - Datum reference
$--DTM,ccc,a,x.x,a,x.x,a,x.x,ccc*hh<CR><LF>
| | | | | | | | |
| | | | | | | | +--- 7
| | | | | | | +------ 6
| | | | | | +---------- 5
| | | | +--+------------- 4
| | +---+------------------- 3
| +------------------------- 2
+---------------------------- 1
1. Local datum W84 - WGS84
W72 - WGS72
S85 - SGS85
P90 - PE90
999 - User defined
IHO datum code
2. Local datum subdivision code
3. Lat offset, min, N/S
4. Lon offset, min, E/W
5. Altitude offset, m
6. Reference dattum W84 - WGS84
W72 - WGS72
S85 - SGS85
P90 - PE90
7. Checksum
GBS -GPS satellite fault detection
$--GBS,hhmmss.ss,x.x,x.x,x.x,x.x,x.x,x.x,x.x*hh<CR><LF>
| | | | | | | | |
| | | | | | | | |
| | | | | | | | +------------------ 9
| | | | | | | +---------------------- 8
| | | | | | +------------------------- 7
| | | | | +----------------------------- 6
| | | | +--------------------------------- 5
| | | +------------------------------------ 4
| | +---------------------------------------- 3
| +-------------------------------------------- 2
+------------------------------------------------------- 1
1. UTC time of the GGA fix addociated with this sentence
2. Expected error in latitude
3. Expected error in longitude
4. Expected error in altitude
5. Most likely failed satellite
6. Probability of missed detection for most likely failed satellite
7. Estimate of bias on most likely failed satellite
8. Standard deviation on bias estimate
9. Checksum
