RTK with Mission Planner (Using QGC for the Survey)

Owned by Conor McCaffrey (Unlicensed)
Last updated: Apr 09, 2021
3 min read

General

RTK GPS uses a stationary base station unit on the ground (Base) to send correction data to a mobile GPS unit on the aircraft (Rover). The RTK corrections allow the rover unit to achieve a higher level of precision and accuracy than would be possible otherwise.

The Base (ground) unit must be positioned in a stable location and not moved. The location can be pre-surveyed or the unit can survey the location itself. This document will cover the self survey procedure, known as a survey-in.

Mission Planner has a built-in utility for acquiring and sending RTK corrections. However, this method does not work reliably with newer GPS units. As a result this manual will cover a method of using QGroundControl to preform a survey-in of a location or set a pre-surveyed location. QGC will then be closed and Mission Planner will be used to pass the corrections through to the vehicle.

Survey-In Position of Ground Station Using QGC

  • Position the ground station GPS antenna where it will not be disturbed and with a clear view of the sky.

  • Connect the base GPS to a Ground Station Computer that will have a wireless link to the aircraft

  • Open QGroundControl

    • The program will automatically detect the GPS unit and start a survey-in

    • The survey-in status can be viewed by clicking the RTK icon in the top menu bar

    • When the RTK icon turns from red to white, as shown in the image below, the survey is complete and the corrections are ready

  • Once the survey is complete close QGroundControl

    • They surveyed location will stay in the F9 unit’s ram memory

  • Proceed to the “Connecting with Mission Planner” section below

Do not move the base station after survey-in has begun or during the use of RTK correction data.

If using a TXMod unit, QGC may automatically detect the connection and block Mission Planner from connecting. In this case click disconnect on QGC then connect with Mission Planner or connect using Mission Planner before opening QGC for the survey.

Change the Survey-In Settings on QGC or Input Pre-Surveyed Coordinates

  • Click the icon in the top left of QGC window

  • Click Application Settings

  • Go to the General menu on the left

  • Scroll down to the RTK GPS settings

  • Here you can change the accuracy, time, or input a pre-surveyed location

  • Restart QGC to make the settings take effect

Connecting with Mission Planner

  • Launch Mission Planner

  • Select “Setup” from the top menu bar

  • Go to the “Optional Hardware” section on the left column

  • Select “RTK/GPS Inject”

  • Select the COM port for the Base RTk GPS unit from the drop down menu

    • Select a baud rate of 115200

  • Check the “Inject MSG Type” and the
    Send GGA?” checkboxs

  • Leave the “M8P/F9P autoconfig” checkbox un-checked

  • Click “Connect”

  • The red boxes for Base, GPS, Glonass, Beidou, and Galileo should start to turn green

    • If the “Base” box and one other bx are green then corrections are valid and ready for transmission to the aircraft

  • Return to the “Data” screen

  • Connect to the vehicle using a telemetry or data radio modem

  • Verify the vehicle has an RTK Float or RTK Fix for the status of a GPS unit (as shown in the image below)

 

BFD Systems – 2020