2-D Coherence Factor for Sidelobe and Ghost Suppressions in Radar Imaging

The coherence factor (CF) is defined as the ratio of coherent power to incoherent power received by the radar aperture. The incoherent power is computed by the multi-antenna receiver based only on the spatial variable. In this respect, it is a 1-D CF, and thereby the image sidelobes in down-range cannot be effectively suppressed. We propose a 2-D CF by supplementing the 1-D CF by an incoherent sum dealing with the frequency dimension. In essence, we employ both spatial diversity and frequency diversity which, respectively, enhance imaging quality in cross-range and range. Simulations and experimental results are provided to demonstrate the performance advantages of the proposed approach.