iSXblue/SXBlue II GNSS Series Technical Reference Manual
124
ARM Status
Field
Description
01
GPS lock
02
DGPS valid data
04
The ARM processor has lock
08
DGPS solution
10
DGPS solution is good
20
Not used
40
Not used
An example of the NavCondition is presented in the following table for the 179889A value.
NavCondition
Field
Description
A
The number of satellites with lock and carrier phase
9
The number of satellites with ephemeris received
8
The number of satellites with healthy ephemeris
8
The number of satellites that are tracked, have an ephemeris,
which is healthy, and are above the elevation mask
9
The number of satellites above the elevation mask
7
The number of satellites with differential
1
The number of satellites with no differential
5.10
RAIM Command and Message
RAIM stands for Receiver Autonomous Integrity Monitoring. RAIM is a GPS integrity monitoring scheme
that uses redundant ranging signals to detect a satellite malfunction that results in a large range error. The
iSXBlue/SXBlue II GNSS uses RAIM to alert users when errors have exceeded a user specified tolerance.
RAIM is available for the SBAS applications.
5.10.1
$JRAIM Command
This command allows you to set the parameters of the RAIM scheme that affects the output of the
$PSAT,GBS message. This command has the following structure:
$JRAIM,HPR,probHPR,probFALSE<CR><LF>
Where:
Variable
Description
HPR
Horizontal Protection Radius (HPR). You will receive notification in the $PSAT,GBS
message that the horizontal error has exceeded this amount. The acceptable range for
this value is 1 to 10,000 meters. The default is 10 meters.
probHPR
Maximum allowed probability that the position computed lies outside the HPR. The
acceptable range for this value is from 0.001% to 50%. The default is 5%.
