I want to use sonar to detect obstacles. But I found the sonar I could buy in my country only could detect meters away. It's frustrating. Anyone knows if there is some advanced sonar that could detect hundreds thousands meters away? Or maybe just mor
Like Amazon Prime Air, carrying something needed and fly for more than one hour.
I don't want to drop a lot of things that should be carried on the copter and make a extreme unuseful toy UAV to fly a longer time just to prove a longer flight time.