Meshtastic as a GNSS RTK data transport?

[Strykar]

RTK GPS are now as cheap as $60-150 offering 1 cm precision with NTRIP corrections.
GPS + BeiDou MSM7's (using only delta encoding + LZ4) we get packet sizes ~64-96 bytes, which could be improved to under 50 bytes assuming 0.2 Hz updates (one correction sent every 5 seconds).

I'd be happy to take a crack at this (I know some bash / python) if a dev could answer:

• Is precise positioning something Meshtastic would want / accept?
• Would extending the Config.Position protobuf to include RTCM / PPP be the Meshtastic way?
• If not, please share some ideas how one could integrate RTCM

Link to Discord discussion.

[garthvh]

Seems like both a lot of data, and way too fast for meshtastic, what would be the use case for the mesh? 60 seconds is a really fast position update for the most common presets, is it useful if sent every 5 minutes?

1-5 seconds is just a no go.

[Strykar]

Five minutes will not work.
I will test soon with longer intervals, a lot depends on the actual receiver and how long it will hold an RTK fix after losing RTCM corrections. This is a good read on the topic - http://lefebure.com/articles/rtk-correction-data-age-accuracy/

[garthvh]

Does not seem like it offers much for meshtastic