Electronics › Electronics › distance measurement › HiSounds like you are looking
February 4, 2018 at 3:39 pm #14720
Sounds like you are looking for something similar to a radar system. If yes, then you should check out this project:
Although such ultrasonic sensors(used in above project) have limited range but it can be replaced with something that measures upto 300m.
I think you will have to look out for some industrial strength type sensors for the same.