Help: Choosing right sensors

I need a optical sensors that could perform the followings:

Some years ago MIT was doing this with video cameras and a lot of processing, to get 3-D positions of cars, people, etc. It would probably be a lot easier now, given the processing power that is available.

Leon

Over 20m, 200m, 2Km? Size of object? Budget? More than one object? Power budget? Can you add reteroreflectors to the object? What is the object?

Over 20m, 200m, 2Km? Size of object? Budget? More than one object? Power budget? Can you add reteroreflectors to the object? What is the object?

over 20m size and object= racing car size budget for sensors < $600 total (i might consider if exceed my budget) more than 1 object. power consumption doesn't matter reteroreflectors allow if weight doesn't influernce performance of the racing car.