Robot tracking

For a project I am making a PacMan sort of game between 2 robots. However, I need a way for the chasing robot to track the other. I was reading and so far saw GPS and RF signal tracking...but I curious of how accurate these are. I really need something to become inches between the escaping car. There will be obstacles in the course for the cars. Any suggestions would be great!


Best method? Best accuracy?

You already posted this question in another forum. Don't double post.