Trimble Outdoors SPSX51 - Manual (Page 146)

B GSOF Messages
144 SPSx51 Modular GPS Receivers User Guide
SV Brief
This message provides brief satellite information. It contains the following data:
• Number of satellites tracked
• The PRN number of each satellite
• Flags indicating satellite status
SV Detail
This message provides detailed satellite information. It contains the following data:
• Number of satellites tracked
• The PRN number of each satellite
• Flags indicating satellite status
• Elevation above horizon, in degrees
• Azimuth from True North, in degrees
18–21 Sigma up Float Meters
22–25 Semi-major axis Float Meters Semi-major axis of error ellipse
26–29 Semi-minor axis Float Meters Semi-minor axis of error ellipse
30–33 Orientation Float degrees Orientation of semi-minor axis, clockwise from
True North
34–37 Unit variance Float Valid only for over-determined solutions. Unit
variance should approach 1.0 value. A value of
less than 1.0 indicates that apriori variances are
too pessimistic.
30–39 Number of epochs short count Number of measurement epochs used to
compute the position. Could be greater than 1
for positions subjected to static constraint.
Always 1 for kinematic.
Table B.11 SV brief (Type 13 record)
Field Item Type Value Meaning
0 Output record type Char 0Dh Brief satellite information output record
1 Record length Char Bytes in record
2 Number of SVs Char 00h-18h Number of satellites included in record 1
1
Includes all tracked satellites, all satellites used in the position solution, and all satellites in view.
The following bytes are repeated for Number of SVs
PRN Char 01h-20h Pseudorandom number of satellites (1-32)
SV Flags1 Char See Table B.21 First set of satellite status bits
SV Flags2 Char See Table B.22 Second set of satellite status bits
Table B.10 Sigma (Type 12 record) (continued)
Field Item Type Value Meaning