Israeli startup Arbe Robotics has a solution to prevent collisions between the increasing number of unmanned air vehicles (drones). It uses radar technology – radio frequencies – to help drones detect objects and avoid crashing. Arbe won the TechCrunch Meetup and Pitch-Off event in Tel Aviv.
http://www.timesofisrael.com/arbe-robotics-uses-radar-to-avoid-drone-crashes/