Trimble Outdoors R7 - Manual (Page 188)

A NMEA-0183 Output
1 7 6 Trimble R7/R8 GPS Receiver User Guide
Tr
imble R7 and R8
GSA
GNSS DOP and active satellites
An example of the GSA message string is shown below. Table A.4
describes the message fields.
$GPGSA,<1>,<2>,<3>,<3>,,,,,<3>,<3>,<3>,<4>,<5>,
<6>*<7>
13 Age of differential GPS data record, Type 1 or Type 9. Null field
when DGPS is not used.
14 Reference station ID, ranging from 0000 to 1023. A null field when
any reference station ID is selected and no corrections are
received.
Table A.4 GSA message fields
Field Meaning
1 Mode 1, M = manual, A = automatic
2 Mode 2, Fix type, 1 = not available, 2 = 2D, 3 = 3D
3 PRN number, 01 to 32, of satellite used in solution, up to 12
transmitted
4 PDOP-Position dilution of precision, 0.5 to 99.9
5 HDOP-Horizontal dilution of precision, 0.5 to 99.9
6 VDOP-Vertical dilution of precision, 0.5 to 99.9
7 Checksum
Table A.3 GGA message fields (continued)
Field Meaning