I'm so surprised by the accuracy while flying, I do wonder how well it will do when flying forward as the sound waves wouldn't return stright up but at an angle, maybe I should actually mound the module at an angle... hmmm.
I don't think it will tilt that much but that would be quite a trick...
The weather is terrible, it's been snowing and I have a bad cold, so haven't been able to do any flying yet, I managed to get the Pixhawk to talk to the computer and phone via the radios so I can easily monitor the sonar reading via the app and/or PC.
Alright so I did the test and it went swimmingly ;-)
No I joke, it was absolutely successful, I simply put the quad in Alt-hold mode and tentatively flew it over the lake with my finger on the mode switch to quickly switch back to Stabilize mode if needed but it wasn't needed at all. The altuitude was maintained perfectly.
The water was very calm for the test so I'm not sure how ripples or other disturbances would affect the performance but in this particular instance it was perfect.
I made a video of the flight but haven't had a chance to process it yet but I'll link it in later and then maybe get to writing an article.
I love the fact that with the sonar the quad follows the terrain so flying back toward land it just "hops" over the rocks as the terrain rises.