Flying with optical flow and recording GPS

ArduCopter Copter 4.0
1

I have a CX-OF sensor and lidar connected to the flight controller along with a GPS module. I set EK2_GPS_TYPE = 3 to disable the GPS being fused in the EKF, as I only want the GPS there for comparison with the optical flow solution as a “Ground truth”.
However, the GLOBAL_POSITION_INT reports the GPS coordinates.
Is it possible to separate the GPS from the EKF?

Thanks,
Daniel

2

Can you try it out with the EFK3 from ArduCopter 4.1.0-dev version?

3

I am a little bit reluctant to switch the EKF, but I will see if it’s possible.

4

I switched to EKF3 and observe the same behavior.
I also tried setting AHRS_GPS_USE = 0.
Is it possible that the GPS isn’t actually being fused, but used only as the EKF origin?

5

You need to use the EKF3 from the ArduPilot 4.1.0-dev version (latest master from github) it has a lot of improvements to GPS denied navigation. And you probably want that.