7
Units M
Meters
Age of Diff. Corr.
second
Null fields when DGPS is not used
Diff. Ref. Station ID
0000
Checksum *18
End of message termination
Table 2-3 Position Fix Indicator
Value Description
0
0 Fix not available or invalid
1
GPS SPS Mode, fix valid
2
Differential GPS, SPS Mode, fix valid
3
GPS PPS Mode, fix valid
2.2.1.2 GNSS DOP and Active Satellites (GSA)
Table 2-4 contains the values for the following example:
$GPGSA,A,3,07,02,26,27,09,04,15, , , , , ,1.8,1.0,1.5*33
Table 2-4 GSA Data Format
Name Example
Units
Description
Message ID
$GPGSA
GSA protocol header
Mode 1
A
See Table 2-5
Mode 2
3
See Table 2-6
Satellite Used
07
Sv on Channel 1
Satellite Used
02
Sv on Channel 2
……
….
Satellite Used
Sv on Channel 12
PDOP
1.8
Position Dilution of Precision
HDOP 1.0
Horizontal
Dilution of Precision
VDOP
1.5
Vertical Dilution of Precision
Checksum
*33
End of message termination
1. Satellite used in solution.
Table 2-5 Mode 1
Value Description
M
Manual—forced to operate in 2D or 3D mode
A
2DAutomatic—allowed to automatically switch 2D/3D
Table 2-6 Mode 2
Value Description
1
Fix Not Available
2 2D
3 3D
2.2.1.3 GNSS Satellites in View (GSV)
Table 2-7 contains the values for the following example:
$GPGSV,2,1,07,07,79,048,42,02,51,062,43,26,36,256,42,27,27,138,42*71
$GPGSV,2,2,07,09,23,313,42,04,19,159,41,15,12,041,42*41
Table 2-7 GSV Data Format