An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution. Two interferometers having very long and nearly equal delays are used in series with the target...http://www.google.de/patents/US5872628?utm_source=gb-gplus-sharePatent US5872628 - Noise pair velocity and range echo location system
