While in Guided Mode, sonar altitude seems not to be considered for altitude. Means for example, while walking down a hill with Tower in loiter (guided) Mode, the copter stays at same absolute altitude, whereas relative altitude raises (indicated correctly by sonar).
Is there a setting which I can modify in Copter 3.4? I would like to set it to “relative altitude” during guided modes.
You talked about Guided mode and Loiter, which is a different mode. If you are really talking about Guided mode then you need to send your position commands with a relative altitude frame. If you mean Loiter mode then you need to enable terrain following (TERRAIN_FOLLOW, read it’s description before enabling).
I think that in Loiter mode the copter holds or rotates in a fixed point in air. So how did you walked with that down a hill. May be you have used another mode like follow me. Or am I wrong?