What is RTCM?

The Radio Technical Commission for Maritime Services (RTCM) is an international non-profit scientific, professional and educational organization. RTCM members are organisations (not individuals) that are both non-government and government. Although started in 1947 as a U.S. government advisory committee, RTCM is now an independent organisation supported by its members from all over the world.

Of particular interest is Special Committee (SC) 104 on Differential Global Navigation Satellite Systems (DGNSS) which defines the transmission standard for the correction information which is used by the various VERIPOS services. The standard typically used by the service providers in the offshore industry is 'RTCM recommended Standards for Differential GNSS Service (RTCM Paper 136-2001/SC104-STD)'.

The following is a list of the commonly used RTCM messages types:

Message Type Description
1 Differential GPS Corrections
2 Delta Differential GPS Corrections
3 GPS Reference Station Coordinates
9 GPS Partial Correction Set
15 Ionospheric Delay Message
16 Informartion Message
31 Differential GLONASS Corrections
32 GLONASS Reference Stations Coordinates

More information can be found at the RTCM website.