Hi @Serch,
The problem you are describing, we first noticed in RangeFinders. I never looked at the problem in TeraRanger’s driver, but you are right, it is there as well (as I just checked).
Basically, the problem was that we weren’t checking the validity of the readings for a few drivers before sending them to the obstacle database.
The good news: I have fixed this issue in Master, and therefore Copter 4.1 Beta should work just fine for you (please let me know if you can test and confirm the same).
The other good news is, that we have backported the fix to Copter 4.0 also ( just a few weeks back). But I don’t think we have any more 4.0.x releases in store so it isn’t immediately available to you, so if you can make a build for yourself, the latest Copter4.0 branch should work just fine for you: https://github.com/ArduPilot/ardupilot/tree/Copter-4.0/
Sorry for the inconvenience
By the way, you say you are using Copter 4.0.7, but the parameter “OA_BR_TYPE” (as mentioned in your post) is only available from 4.1 onwards