NavCom Sapphire Rev.J - Manual (Page 318)

Sapphire Technical Reference Manual Rev. J
318
2.66 NMEAGSV (ASCII)
SF-3050 Sapphire SF-3040
Supported Output Rate: OFF ONCE OnChange OnTime
OnChange = when slow nav is completed (1Hz)
OnTime = minimum 1Hz
This output message reports data associated with satellites in view, based on almanac data.
Data includes PRN number, elevation, azimuth and SNR values. Note that one GSV sentence
can only provide data for up to 4 satellites, so several sentences may be required for full
“satellite in view” information. The format for this message is in compliance with NMEA-0183
Standards version 3.0. The addition of Field 8 brings this message compliant to NMEA v4.1.
Table 153: GSV Message Output Format
Output
Format:
$GPGSV,total,message,totalsv,prn1,elev1,azim1,snr1,…..,prn4,elev4,azim4,snr4*checksum
Field# Field Name Description
F1 Total Total number of messages for full information
F2 Message Message number
F3 Totalsv
Total number of satellites in view that will be included in the messages (up to
4 satellites per message)
F4 Prn Satellite PRN number
F5 Elev Elevation for the corresponding satellite in degrees (0 to 90)
F6 Azim Azimuth for the corresponding satellite in degrees (0 to 359)
F7 Snr Signal to Noise ratio for the corresponding satellite
F8 Signal ID 1 for L1CA, and 0 for L1+L2 (see note 1) (NMEA v4.1 only)
F9 *CRC Checksum
Examples: $GPGSV,3,1,11,13,68,347,50,23,66,87,50,25,56,40,50,27,45,277,46*78
$GPGSV,3,2,11,16,23,44,45,20,22,174,36,08,21,259,38,03,21,103,36*43
$GPGSV,3,3,11,19,09,128,32,04,05,266,34,02,01,301,30,,,,*44

1
: To meet the new Signal ID requirements for IEC61162 4
th
Edition, the GSV sentence is
output in two groups, one group with Signal ID 1, which are the Satellites that are being
tracked with L1CA or G1C only. The second group is sent out with the rest of the satellites
that are being tracked with L1CA/G1C and L2P/G2C with Signal ID 0, indicating multiple
signals. A signal ID 0 is given to a group of sats once they have LOCKED on an L2 signal.
Example of NMEA v4.1 format :
$GPGSV,3,1,10,26,20,048,47,06,19,316,46,,,,,,,,,1*66
$GPGSV,3,2,10,18,71,254,53,21,65,360,51,29,46,145,52,15,43,083,51,0*6C
$GPGSV,3,3,10,22,29,237,49,30,22,265,50,16,21,298,48,03,04,320,43,0*69
$GLGSV,2,1,07,81,77,060,54,66,66,018,54,67,56,229,51,82,34,331,51,1*7D
$GLGSV,2,2,07,88,28,132,49,65,12,034,,68,05,219,46,,,,,1*4C