[EricH]

I'd rather see 1-2 April Tags on the field. A team who knew what they were doing and the location of the tag(s) could get a pretty good estimate of where they were even if camera(s) on the robot could only see one.

An April Tag looks like a less-detailed QR code. I understand that by looking at size and angles of the lines in it, angle and distance can both be calculated.