Dopler Circuit

[David V. Rogers]

I have, amongst my 10-GHz WBFM gear, a dual-detector rig which
probably came out of some sort of motion detector.  With the dual
detectors, it could ascertain direction of motion, presumably
speed, and other information which would reduce false alarms.  It
occurs to me that the dual detectors would allow the capability
for distance measurement for 10-GHz contacts.  Does anyone know
of a circuit that I could build which would allow some dopler
monitoring/processing that could measure distances of up to
150-200 km?
73 de Dave (K9RKH)