ashtech GG Surveyor, Reference Manual

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Command/Response Formats 133
Com
m
and
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$PASHQ,AIM,x
The associated query command is $PASHQ,AIM,x. This command outputs the AIM
response message on port x, where x is the optional output port. This message is not
output unless a position is computed.
Example:
$PASHQ,AIM,A
$PASHR,AIM
The response message to the set or query command is in the form:
$PASHR,AIM,s1,d1,n(d2-d3)*cc
n = number of channel - SV pairs
Table 6.44 outlines the structure of the RAIM response message.
Example:
$PASHR,AIM,NPA,1,10-12,05-20*FF
where:
NPA = non-precision approach mode
1 = error detected and corrected
10-12 = channel 10, satellite 12 excluded
05-20 = channel 5, satellite 20 excluded
When RAIM returns 0, no errors exceed the alarm limit. All computed satellite ranges
are used in the position velocity calculation.
Table 6.44: RAIM Response Message Structure
Field Description
s1 Current RAIM mode (3-character)
OFF - Turns RAIM off
NPA - Non-precision approach, alarm limit is 0.030 nmi
TER - Terminal, alarm limit is 1.00 nmi
ERT - En route, alarm limit is 2.00 nmi
n.nn - user-selectable alarm limit between 0.015 and 4.00 km
d1 Value returned by RAIM gives:
0 - no errors detected
1 - error detected and corrected
2 - error detected, correction not possible
3 - detection not available (lack of satellite or poor geometry)
4 - error detected, rest of satellite set not available
d2-d3 d2-d3 represents a pair of excluded channel and its corresponding satellite, where d2 is
the number of the excluded channel and d3 is the number of the corresponding satellite