Experimental observation and modeling of overland height finding

We present airborne experimental observations at UHF and VHF of electromagnetic scattering from terrain and demonstrate how such a signal can be used to determine target height. We describe the time difference of arrival (TDOA) processing and then go on to discuss how Doppler information can be used to supplement or replace TDOA processing. We describe two such methods. The first entails observing the Doppler separation between the target and its image and inverting to recover height. The second method uses the Doppler domain to filter out-of-plane energy and improve the performance of TDOA processing