Intrapulse Forwarding Jamming Detection and Identification Framework for Airborne Radar System Under Clutter Environment

Accurate jamming detection and identification (JDI) are essential prerequisites to effectively implement anti-jamming measures. However, the significant mainlobe clutter complicates JDI in airborne radar systems, limiting the improvement of jamming-to-clutter ratio. To address the issues of intra-pulse forwarding jamming (IPFJ) detection and identification under clutter environments, this paper proposes a JDI framework based on mismatched filtering and difference cosine similarity test (DCST). The proposed framework comprises three stages: mismatched filtering, data deviation factor (DDF)-based detection and DCST-based identification. Firstly, the mismatched filter is designed to suppress the energy of target and clutter. Specifically, the filter coefficients are designed to be orthogonal to the radar signal. After mismatched filtering, IPFJ detection is performed through DDF, and the echo corresponding to the IPFJ's Doppler frequency is extracted. Subsequently, DCST is employed to match the jamming template, thereby achieving the jamming identification. Finally, digital simulations and comparative experiments are conducted to confirm the reliability of the framework. The proposed method achieves a $C$ factor below 0.1 at a jamming-to-clutter-plus-noise ratio (JCNR) of -22dB, indicating superior detection performance. Furthermore, it attains an identification accuracy exceeding 90% for JCNR below -19dB, outperforming other methods by 30%.