A critical review of a matched filter receiving radar echoes from extended targets

The matched filter princiiple is discussed, with emphasis placed on its dependence on a thorough knowledge of the signal waveform. It is found that the matched filter can be successfully applied to processing echo returns of point targets. However, inverse filtering is a straightforward method if restoration of extended targets is required. The use of matched filters in Sar signal processing is successful not because of the matched filter principle but because of the characteristics of the particular inverse filter required; this can be simulated (to an approximation) with a conjugate transfer function. An example is presented to illustrate that the performance of an inverse filter is superior to that of a matched filter. A simple square pulse is assumed.