Which RTCM messages are necessary for RTK corrections?

I am wondering which RTCM messages are absolutely critical for RTK to work. For example, the messages seem to be by constellation. Which messages must be present and how do they contribute to the overall function?

Start here:

Generally, you could probably get away with1005 and the MSM4 (i.e. 1074 for GPS) messages for the constellations you need.


You absolutely need the ARP message at 0.1 hz, it is arguably the most important message. Its sets the baseline for everything else.

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Hi @jherbranson,

If we talk about Reach devices, they require at least GPS observables and ARP coordinates. Different RTCM messages may contain this info. For example, Reach can accept GPS data from 1004 Extended L1/L2 GPS RTK Observables or 1074 GPS MSM4.

Is there a specific 3rd-party device you want to check compatibility with?

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