Extending observation coverage of sar by separating range ambiguous signals using pn-sequences

To extend the observation coverage of synthetic aperture radar (SAR), existing methods cost spatial resolution and/or power consumption. In this paper, we propose to separate range ambiguous signals by applying Pseudo Noise sequence (PN-sequence) to Frequency Modulation chirp (FM-chirp) pulses and observe multiple observation swaths. Experimental results show that the proposed method successfully separates multiple range ambiguous signals. Compared with the cases using the traditional FM-chirp pulses, the proposed method suppresses range ambiguities 21.6 to 23.8 dB.