21
6.2 GSA – DOP And Active Satellites
GPS receiver operating mode, satellites used in the navigation
solution reported by the GGA sentence, and DOP values.
$GPGSA,a,b,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,p.p,h.h,v.v*hh<CR><LF>
A
Mode: M = Manual, forced to operate in 2D or 3D mode. A=
Automatic, allowed to automatically switch 2D/3D.
B
Mode: 1 = Fix not available, 2 = 2D, 3 = 3D
xx
ID (PRN) numbers of GPS satellites used in solution
p.p PDOP
h.h HDOP
v.v VDOP
6.3 GSV – Satellites In View
Number of satellites in view, satellite ID (PRN) numbers, elevation, azimuth, and SNR value. The
maximum information for each message is four satellites. Additional messages up to a maximum
of eight is sent as needed. The satellites are in the PRN number order.
Only the SNR (signal to noise ratio) value is available until a position fix is attained. The
elevation and azimuth angles are also added after a fix. Note that there CAN be “theoretical”
satellites in the GSV message. These are the satellites with known angles (elevation, azimuth), but
for some reason, e.g. due to an obstruction, have not been found by PCM3292. The SNR value for
these satellites are set to zero.
Please notice that as all viewable satellites are reported, the amount of satellites may occasionally
be exceed the number of receiver tracking channels, 12.
$GPGSV,n,m,ss,xx,ee,aaa,cn,…………. ,xx,e ee,aaa,cn*hh<CR><LF>
N
Total number of messages, 1 to 9
M
Message number, 1 to 9
Ss
Total number of satellites in view
Xx
Satellite ID (PRN) number
Ee
Satellite elevation, degrees 90 max
Aaa
Satellite azimuth, degrees True, 000 to 359
cn
SNR ( C/No) 00-99 dB-Hz. zero when not tracking
