Sub-Resolution Multipath Mitigation in Radar Transponders by Range Compression and Adaptive Filtering

This paper presents a method capable of eliminating sub resolution multipath interference for transponders, that can be used in interferometry-based radar applications, such as phased-array or synthetic aperture imaging. The proposed method differs from classical methods or prior art, because it is based on range compressing (matched filtering) the received pulse before being processed by adaptive filters, such that a higher signal to noise ratio (SNR) is achieved and accurate convergence of the algorithm is assured. Contrarily, by not compressing the received pulse, adaptive filters cannot resolve the sub resolution targets and in most situations, distort the desired signal even more than it was to begin with. We further analyze two different configurations of implementing the proposed method: the first is a low-computational implementation which needs to be calibrated periodically and the second is a high-computational method, which needs no calibration.