Field
Description
a
Mode
M = Manual, forced to operate in 2D or 3D mode
A = Automatic, allowed to change automatically between 2D
and 3D
x
Mode
1 = Fix not available
2 = 2D
3 = 3D
xx
PRN numbers of the satellites used in the solution.
For NMEA v4.0:
This field is repeated 12 times.
For NMEA v4.1:
This field is repeated 16 times.
☞
A new GSA message is sent for each GNSS constel-
lation tracked.
For NMEA v4.0 and v4.1:
GPS
1 to 32
GPS satellites
33 to 64
SBAS satellites
65 to 99
Undefined
GLONASS
1 to 32
Undefined
33 to 64
SBAS satellites
65 to 99
GLONASS satellites
For NMEA v4.1 also:
Galileo
1 to 36
Galileo satellites
37 to 64
Galileo SBAS
65 to 99
Undefined
BeiDou
1 to 37
BeiDou satellites
38 to 64
BeiDou SBAS
65 to 99
Undefined
x.x
PDOP
x.x
HDOP
x.x
VDOP
h
For NMEA v4.1. GNSS System ID
1 = GPS
2 = GLONASS
3 = Galileo
4 = BeiDou
*hh
Checksum
<CR>
C
arriage
R
eturn
<LF>
L
ine
F
eed
NMEA Message Formats
1023