SAR-ECCM using phase-perturbed LFM chirp signals and DRFM repeat jammer penalization

This work is concerned with developing radar signaling strategies and algorithms that enhance the performance of a synthetic aperture radar (SAR) to image targets in the presence of digital radio frequency memory (DRFM) repeat jammers. The approach is based on a manipulation/alteration of the transmitted signal and/or its parameters in the fast-time domain at every position of the synthetic aperture (pulse repetition interval, PRI); this scheme is known as pulse diversity. In particular, we utilize a modulated form of the transmitted chirp signal and/or vary the rate of the chirp at each PRI; the modulation and/or the rate is varied from one PRI to another, and these variations are only known to the user. The merits of these pulse diversity methods are studied using the autocorrelation and cross-correlation of these signals. We also present a signal processing method for penalizing a DRFM jammer that tries to repeat the radar signal.