Interrupted sampling repeater jamming suppression based on the signal with thumbtack ambiguity function

Abstract

In this paper, an effective interrupted sampling repeated jamming (ISRJ) suppression method is proposed. ISRJ is generated by the jammer intercepting and forwarding the radar signal. The signal intercepted by the jammer can be considered as the sum of the radar signals with different amplitudes and frequency shifts. Therefore, when we use the signal with the thumbtack ambiguity function for target detection, ISRJ can form multiple false targets in the range-Doppler (RD) spectrum, and these false targets are distributed at different Doppler frequency units. Using this feature, we first propose a Doppler compensation method to construct the RD spectrum of the monopulse echo, in which the true and false targets can be effectively identified. Further, we perform orthogonal projection in the Doppler dimension to filter out the true target and obtain the false target RD spectrum. Finally, we use the constructed RD spectrum to cancel with the false target RD spectrum to achieve ISRJ suppression. The simulation results verify the effectiveness of the proposed method.