Hello peeps 
I have been doing an SITL + Gazebo simulation of several ArduCopter features, surface tracking being one of them. However, during my little project, I discovered that surface tracking is not present even after the addition of simulated peripherals like range finder and optical flow. I then looked through SITL.cpp and discovered that it was not a user settable parameter. Is it possible to test surface tracking in SITL + Gazebo in any way?