RTK Correction from Fixed Base to improve accuracy of Moving Base configuration

[Jord_Howard]

I’m currently using a moving baseline configuration (2x F9P’s from HolyBro with the ‘Base’ antenna). It’s working well so far. I’m now chasing increased accuracy, preferably using RTK correction from a Fixed Base.

My trouble is how to impliment this. I am constrained as my rover is planned to be an autonomous system and will operate without supervision (or a mission planner connection) at times (in an agricultural environment). Therefore I don’t believe that injecting either NTRIP or RTK correction via mission planner is a feasible solution in my use case (if I’ve overlooked something please let me know). Additionally, to have setup the gps moving baseline configuration I have a cable connection both of my F9P modules on their UART2 ports. Leaving me without a port on the F9P’s to connect a telemetry radio as described in method 3 here.

Under the GPS for Yaw page (link, under RTK Correction) it states that “RTCM correction data it receives over MAVLink from a GCS or telemetry radio (from a fixed baseline RTK base station) to these GPSes”. Does this mean I can have a telmetry radio on my fixed base (UART2 of F9P) and on my FC (Pixhawk 6X, TELEM1) and the correction messages will be passed to the GPSes? If so, will I still be able to use the same radio to connect the rover to mission planner periodically, or will there be clashes?

[JirikCZ (Jiri Landa)]

I use F9P + ESP32 as a base station (WIFI client with static IP), this ESP sends RTCM3 to my Wifi network. It has its own NTRIP server. I have a public IP address. There is also an F9P on the rover, preferably simpleRTK2B. However, I did not use WIFI as an RTK receiver on the rover, because I wanted to be sure that RTK will be always and everywhere, I connected the HC-06 bluetooth module to the simpleRTK2B. This has the advantage that the RTK is received by the phone via the Lefebure.com application and forwards RTCM3 via bluetooth to the F9p on the rover. The phone is able to automatically switch between all WIFI SSIDs in my large area and still draw RTCM3 from my network. If I get outside my Wifi, the phone switches to data and thanks to the public address of my ESP32 station, it continues to receive RTCM3 corrections and transmits them via bluetooth to the rover. A telephone is always present on board the Rover.
video: https://www.youtube.com/watch?v=KGQ1xdwAq1A&t=230s

The ESP32 was necessary because the C099-F9P cannot do WIFI client mode.