Doppler compensation for passive coherent location

Abstract

For target movement without velocity information in a passive coherent location system, the unknown Doppler shift between the direct signal and the target echo results in a decrease of the highest peak output value and the occurrence of some false peaks. Several Doppler compensation methods are compared in terms of the Doppler decorrelation loss factor. The Doppler decorrelation loss from the different inherent correlation times of signals and the different overlap times in the cross-correlator is analyzed. Simultaneously, the rationality of two stage processing is explained. In order to reduce the computational burden much more, an FFT pruning algorithm is introduced into segment Doppler compensation. The results of simulations are in close agreement with theory predictions.