What is "rtcm"

The Radio Technical Commission for Maritime Services (RTCM) is an international standards organization.

The Radio Technical Commission for Maritime Services (RTCM) is an international non-profit scientific, professional and educational organization. RTCM members are organizations (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 organization supported by its members from all over the world.

In the United States, the Federal Communications Commission and U.S. Coast Guard use RTCM standards to specify radar systems, Emergency Position Indicating Radio Beacons, Differential GPS systems and the basic version of Digital Selective Calling radios.