iSXblue/SXBlue II GNSS Series Technical Reference Manual
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5.9.5
GST Data Message
The GST message contains Global Navigation Satellite System (GNSS) pseudorange error statistics. The
table below breaks down the GST message into its components. This message has the following format:
$GPGST,hhmmss.ss,a.a,b.b,c.c,d.d,e.e,f.f,g.g *cc<CR><LF>
Table 5-16 GST Data Message Defined
Field
Description
Hhmmss.ss
UTC time in hours, minutes, seconds of the GPS position
a.a
Root mean square (rms) value of the standard deviation of the range inputs to the
navigation process. Range inputs include pseudoranges and differential GNSS (DGNSS)
corrections
b.b
Standard deviation of semi-major axis of error ellipse (meters)
c.c
Standard deviation of semi-minor axis of error ellipse (meters)
d.d
Orientation of semi-major axis of error ellipse (degrees)
e.e
Standard deviation of latitude error (meters)
f.f
Standard deviation of longitude error (meters)
g.g
Standard deviation of altitude error (meters)
*cc
Checksum
<CR><LF>
Carriage return and line feed
5.9.6
GSV Data Message
The GSV message contains GPS satellite information. Null fields occur where data is not available due to
the number of satellites tracked. The Table below breaks down the GSV data message into its
components. This message has the following format:
$GPGSV,t,m,n,ii,ee,aaa,ss,…ii,ee,aaa,ss,*cc<CR><LF>
Table 5-17 GSV Data Message Defined
Field
Description
t
Total number of messages
m
Message number, m = 1 to 3
n
Total number of satellites in view
ii
Satellite number
ee
Elevation in degrees, ee = 0 to 90
aaa
Azimuth (true) in degrees, aaa = 0 to 359
ss
SNR (dB) + 30, ss = 0 to 99
*cc
Checksum
<CR><LF>
Carriage return and line feed
