Sparsity-Based Modelling of Compact Target Echo in PCL Radar

摘要

A passive coherent location radar makes use of transmitters already present in its environment that illuminate the surveyed area. A passive radar consists solely of a receiver that collects the waves reflected from objects of interest (targets in radar terminology) and correlates them with a direct wave from the transmitter. As the illumination is continuous, the radar suffers from near-far effect: strong echoes from near objects blind the detector from detecting weaker echoes of far objects. This may be mitigated with CLEAN method, which, however, requires precise strong echo modelling to be effective. The paper presents a method for accurate modelling of an echo in case of compact target - i.e. when signal bandwidth is insufficient for accurate resolving the target details. The method is based on the assumed sparsity of the target, which is usually adequate, as a typical object acts as a small number of point scatterers with respect to radar waves. The modelling method is analyzed with respect to the residual power after removal of modelled echo from the original signal.