Send RTK base station corrections to ArduPilot with Mission Planner, QGroundControl and MAVProxy

With Mission Planner the process is extremely easy, the instructions are the same for simpleRTK2B, simpleRTK2Blite (u-blox ZED-F9P) and simpleRTK3B (Septentrio Mosaic X5) receivers:

1. Configure your GNSS receiver as a base station
2. Connect the GNSS receiver to your PC
3. Connect the autopilot or radio telemetry link to your PC
4. Open Mission Planner and connect to your autopilot as usual
5. In Mission Planner, go to SETUP >> Optional Hardware > RTK/GPS Inject
6. Select the COM port where your GNSS base station is connected to and set the proper baudrate
7. Click Connect button
8. If everything is correct, you will see a summary of GPS signal status and generated RTCM messages as well as your GNSS base station position on the map
9. The GNSS receiver connected to your autopilot will receive RTCM corrections and enter into fixed/float RTK mode

When you go back to Mission Planner main screen you will see the base station position as well as your Ardupilot GNSS position:

QGroundControl detects automatically both the simpleRTK2B and simpleRTK3B boards (not simpleRTK2Blite), connected via USB to the same computer as QGroundControl runs.

It configures automatically the receiver and starts streaming corrections to the GNSS receiver mounted on the Autopilot.

We have tested the automatic configuration and the behavior is not always the expected one, so in this tutorial we will show an alternative method that also supports simpleRTK2Blite receivers as base stations and works 100% of the time.

Apart from QGroundControl, you will need to install the following (free) applications:

• MAVProxy
• RTKlib strsvr

1. Connect the autopilot or radio telemetry link to your PC
2. Open QGroundControl
3. Go to main menu > Application Settings > General > AutoConnect to the following devices > Unselect RTK GPS
4. Configure your GNSS receiver as a base station
5. Connect the GNSS receiver to your PC
6. Run STRSVR application
7. Select (9) Input as Serial port, click Opt … button
8. Set Port to the COM port of your GNSS receiver base station
9. Set Bitrate (bps) to your GNSS receiver baudrate, click OK
10. Select (1) Output as NTRIP Caster, click Opt … button
11. Set Port, for example 2101
12. Set Mountpoint, for example TEST
13. You can leave UserID and Password empty, click OK
14. Click Start
    
15. Run MAVProxy
16. Go to Link > Add > Serial > Select the telemetry link or autopilot COM port and baudrate. If connection is ok, your MAVProxy screen should look like this:
    
17. Open MAVProxy terminal window
18. Type:

    module load ntrip
    ntrip set caster 127.0.0.1
    ntrip set port 2101
    ntrip set mountpoint TEST
    ntrip start

    
19. After this step, STRSVR should look like this:
    
20. The GNSS receiver connected to your autopilot will receive RTCM messages from your base station automatically and enter RTK fix/float mode.