ashtech DG16 - Page 146

126 DG14 and DG16 Board & Sensor Reference Manual
$PASHQ,ION,[c1]
This command queries the current ionospheric data generated by the GPS
satellites, where c1 is the optional port designator for the output of the response. If
a port is not specified, the receiver sends the response to the current port.
Ionospheric and tropospheric modelling are enabled when the receiver is functioning in stand-
alone mode (autonomous mode), but are disabled if the receiver is set as an RTCM base or rover,
since differential corrections already compensate for ionospheric and tropospheric delays.
$PASHR,ION
The response message is output in binary format:
$PASHR,ION,<Binary Data String + Checksum>
Table 6.27 describes the elements in the binary data string:
Table 6.27. $PASHR,ION Format
Type Size Contents
float 4 a
0
ionospheric parameter (seconds)
float 4 a
1
ionospheric parameter (sec. per semicircle)
float 4 a
2
ionospheric parameter (sec. per semicircle)
float 4 a
3
ionospheric parameter (sec. per semicircle)
float 4 b
0
ionospheric parameter (seconds)
float 4 b
1
ionospheric parameter (sec. per semicircle)
float 4 b
2
ionospheric parameter (sec. per semicircle)
float 4 b
3
ionospheric parameter (sec. per semicircle)
double 8 A
0
Constant term of GPS/UTC polynomial
double 8 A
1
Constant term of GPS/UTC polynomial
unsigned long 4 t
ot
Reference time
short 2 W
nt
reference week
short 2 Dt
LS
Delta UTC-GPS time at reference time
short 2 WN
LSF
Week of leap second correction
short 2 DN day of leap second correction
short 2 Dt
LSF
Delta time between GPS and UTC
short 2 WN Current GPS week number