Spectra Precision ProMark 800 Reference Manual - Manual (Page 96)

84
RTK Implementation
Standard Formats CMR, CMR+
CMR (for Compact Measurement Record) is a non-proprietary
RTK format that uses data compression techniques to reduce
the bandwidth required to transmit the RTK data. In other
words, the amount of data to be transmitted on the data link
is less with CMR than with many other formats.
There is also an enhanced version of this format called
CMR+.
RTCM
RTCM (for Radio Technical Commission for Maritime
Services) is the most widespread standard format for
transporting RTK correction data. As listed below, there are
several versions of the RTCM format available in Spectra
Precision receivers:
RTCM2.3. The message types that exist in this version are
numbered from 1 to 34. The most important ones are listed
below:
Message Type
Transfer Rate
(default)
Range
Observables 1 second
Less than 1 second up
to 300 seconds
Coordinates of base position 30 seconds 1 to 300 seconds
Base description 30 seconds 1 to 300 seconds
Message
Type
Description
Default Transfer
Rate
1, 9 Differential GPS Corrections
3 ECEF XYZ base coordinates
16, 36 GPS special message
18 Uncorrected carrier phase 1 second
19 Uncorrected pseudo-ranges 1 second
20 RTK carrier phase corrections
21
RTK high-accuracy, pseudo-range correc-
tions
22 Extended base parameter
23 Antenna type definition 31 seconds
24 Antenna reference point 13 seconds
31, 34 Differential GLONASS corrections
32
GLONASS Reference Stations Parame-
ters