Ultra-Wide Swath SAR Range Ambiguity Suppression with Chaotic Frequency Modulation Signals

Different from the traditional wide-swath synthetic aperture radar (SAR) system, ultra-wide swath SAR can achieve ultra-wide swath observation without the expense of an unimpaired azimuth resolution. However, due to the limitation of one receiving window, the radar echoes of near-range and far-range scatters arrive at the SAR receiver simultaneously, and this leads to the range ambiguity occurrence. This paper proposes a novel method based on chaotic frequency modulation (CFM) signals is proposed to suppress range ambiguity in ultra-wide swath synthetic aperture radar (SAR). Time-variant transmission avoids mutual interferences from the radar echoes of near-range and far-range scatters due to the uncorrelated property. Simulations and experiments on raw data are performed to verify the effectiveness of the proposed method.