Optical flow calibration without GPS

Hello. I have set the optical flow for loiter. However, I want to make an autotuning. The problem is that in the documentation, it tells to climb in loiter with GPS, then land and go loiter again without it. I don’t have GPS available in my application. Should I put it for the calibration and then get it off the drone, or I can just make the autotuning with optical flow only? Thanks and sorry for my english

Put the GPS in
Tune it
Remove the GPS