I'm working on a security application that detects a moving object (usually
a human  ...) in an outdoor space measuring approx 200 x 500 ft. Output are
x/y (maybe even z) coordinates, which are fed to a  x/y/z- mount with a
video camera on it. Mount gets coordinates, aims, zooms in, focuses -
smile!. Video camera and x/y/z mount are done. All I need is the ranging
module. Ultrasound is out of the picture because of the distances involved.
Motion detectors etc. don't work, because I need the exact location of the
object, not just presence detection.

Any ideas?