Table of Contents
Advertisement
$GPMSG
The response message format depends upon the RTCM message type enabled: types
1 and 31 are enabled by default; types 3, 9, 16, 32, 34, and 36 must be enabled by the
$PASHS,RTC,TYP set command.
The format for RTCM message types 1, 9, 31, and 34 is:
Message types 1 and 9 output correction information for GPS satellites, while message types 31 and
34 output correction information for GLONASS satellites.
Differential GPS Corrections (Type1) and GPS Partial Correction Set (Type 9)
Table 6.62 outlines the $GPMSG response structure.
Message types 1/31 and 9/34 are identical except for the fact that message type 1/31 has correction
information (fields 9, 10, 11, 12, 13) for all GPS+GLONASS satellites, and each message type 9/34
has correction information for up to 3 GPS+GLONASS satellites per transmission. Note that for
message types 01 and 09, GPS PRN numbers are between 1 and 32, and for message types 31 and 34,
GLONASS ID numbers are between 1 and 24 (GLONASS slot numbers).
150
$GPMSG,d1,d2,f1,d3,d4,d5,m1,d5,d7,f2,f3,d8*cc
Table 6.62: $GPMSG Structure for RTCM Message Types 1 and 9
Field
d1
RTCM type, 01, 09, 31, or 34
d2
Station identifier, 0000 to 1023
f1
Z count in seconds and tenths, 0000.0 to 3600.0
d3
Sequence number, 0 to 7
d4
Station health, 0 to 7
d5
Total number of characters after the time item, 000 to 999
m1
Current UTC time of position computation in hours, minutes, and seconds
d6
User differential range error (UDRE)
d7
Satellite PRN number. GPS satellites for message types 1 and 31 and
GLONASS satellites for message types 9 and 34.
f2
Pseudo-range correction (PRC) in meters
f3
Range rate correction (RRC) in meters/sec
d8
Issue of data (IODE) for message types 1 and 9, and reference time of
GLONASS ephemerides (TB) for message types 31 and 34.
*cc
Message checksum in hexadecimal
Description
GG Surveyor GPS+GLONASS Reference Manual
Advertisement
Table of Contents
