I'm trying to build a system that would allow me to monitor a moving object in real time, to estimate its average speed over a fixed distance. The issue is that the object is a drone, it can't be guaranteed to cross a specific horizontal or vertical line, so using a lidar, or an ultrasonic sensor didn't seem like a good way to go. The other concern is the accuracy, latency/delay in timing between start and finish, even in milliseconds isn't acceptable.
The system I'm trying to build consists of three components, a start line, a finish line and a tag/ some type of transmitter.
The starting line and finish line are two identical devices that would detect when the tag crosses them, so when the drone starts and finishes the journey, but my application requires being able to detect the drone even if it was to be high from the ground, say 10-15 meters. I tried researching suitable sensors but had no luck figuring out what suits my needs.
Any suggestion for the hardware would be greatly appreciated