I’ve heard good things about using rangefinding when trying to set up autolanding on a plane. I’m considering a $25 ultrasonic sensor (Maxbotix EZ4) and a $45 ToF sensor (TFmini). Seems like the ToF has slightly longer range, but I’m not clear on the advantages of one technology over the other. Anyone have experience with these types of rangefinders and autolanding? I’m willing to shell out $20 for the ToF sensor, but only if there’s going to be a performance or reliability benefit.
Plane or Quad? Not clear. when you say Plane, are we talking about VTOL?
This is for a plane, regular not quad.
Wow the TF-Luna is dirt cheap! With a range of only 8m it’s only a little better than the Maxbotix, but similar price. Resolution on the Luna is 1cm as opposed to 1in. But it seems like the big drawback is power consumption: 350mW for the Luna but only 10mW for the Maxbotix!
Given the similar price and performance numbers are there any other intrinsic factors of these technologies that make one better than the other? I read that ToF sensors can be noisy outdoors whereas sonars are less affected. The greater power draw for the Luna seems like a big downside but IIRC Ardupilot has a parameter for disabling rangefinders above a certain altitude, so maybe it’s not a big deal.
Your budget is very limited. You will not find anything in this price range.
LiDars start at 20 dollars to 29,000 dollars each 
I was considering the TF02, but will probably hold off on that unless the cheaper options are problematic.