NMEA-0183 message: GSA

GPS DOP and active satellites

An example of the GSA message string is:

$GNGSA,A,3,21,5,29,25,12,10,26,2,,,,,1.2,0.7,1.0*27

$GNGSA,A,3,65,67,80,81,82,88,66,,,,,,1.2,0.7,1.0*20

GSA message fields

Field

Meaning

0

Message ID $GNGSA

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 for GPS
33 to 64 for SBAS
64+ for GLONASS

4

PDOP: 0.5 to 99.9

5

HDOP: 0.5 to 99.9

6

VDOP: 0.5 to 99.9

7

The checksum data, always begins with *

If NMEA-0183 version 4.10 is selected, the 7th and 8th fields become:

Field

Meaning

6

System ID based on:

BeiDou

4

7

The checksum data, always begins with *