A Time-Domain Filtering Method Based on Intrapulse Joint Interpulse Coding to Counter Interrupted Sampling Repeater Jamming in SAR
Jingyi Wei, Yachao Li, Rui Yang, Endi Zhu, Jiabao Ding, Mingyue Ding, Pan Zhang
Abstract
The interrupted sampling repeater jamming (ISRJ) can effectively degrade the image quality and affect the subsequent target recognition by creating deceptive multiple false targets on synthetic aperture radar (SAR) images. A time-domain filtering method based on pulse coding to counter ISRJ is proposed in this article. First, this coding method requires the radar to transmit a full pulse signal consisting of multiple subpulse signals several times in the original pulse repetition interval (PRI), and there is a difference in the time distribution of the subpulses transmitted at different moments. Then, use the observation matrix determined by the echo conditions contained in each receiving window to filter the echo in the time domain to obtain the echo corresponding to each subpulse. Finally, the subpulse echo of the jammer sampling section is discarded and the remaining uninterfered subpulse echoes are segmented for pulse compression and subsequent imaging processing to obtain SAR images with a low jamming-to-signal ratio (JSR). Several groups of simulations show that the proposed method is effective against different kinds of ISRJ, and this time-domain filtering method can improve the effect of radar anti-ISRJ and has a high freedom of waveform design.