An Adjacent Area Jamming Method Against SAR Based on Partial-Pulse-Reception and Full-Pulse-Recovery Scheme

Abstract

The forwarding (repeater) jamming has been widely used in synthetic aperture radar (SAR) countermeasures. However, when the jammer has a time division requirement for reception and transmission, the operation that the jammer first receives the entire SAR pulse and then transmits the jamming signal will result in a long forwarding delay. Especially for spaceborne SAR with a pulse duration of tens of microseconds, long delay means that the jamming can only cover areas several kilometers away from the jammer, and targets close to the jammer are difficult to protect. To address this issue, a partial-pulse-reception and full-pulse-recovery jamming scheme is proposed in this article. The core of this scheme is to recover the partial pulses intercepted by the jammer into a pulse with a complete pulse duration. A pulse recovery method based on 2-D joint parameter estimation is proposed, in which the problem of pulse recovery is transformed into a parameter estimation problem for single-tone signals. In addition, with the help of processing tools such as wave gate limitation and Kalman filtering, the robustness of this method is improved, and it can still work at an signal-to-noise ratio (SNR) as low as $-$30 dB. The effectiveness of the proposed method is verified through experiments using measured and simulated data under different SNR conditions.