Anti-interrupted Sampling Repeater Jamming Method in the Waveform Domain before Matched Filtering

Interrupted Sampling Repeater Jamming (ISRJ) falls within the category of intrapulse coherent deception interference. ISRJ employs the principle of undersampling to engender multiple spurious target peaks on the range profile, thereby disrupting the detection and tracking of genuine targets. To address this challenge, this study introduces a novel method grounded in the waveform domain to mitigate ISRJ before matched filtering. First, considering the partial matching attributes of ISRJ, an expanded domain, specifically the waveform domain, is incorporated into the matched filtering. This augmentation enables the investigation of local features within the interference signals and components of authentic target echo signals. Moreover, adaptive threshold functions are defined for each waveform domain. Subsequently, the introduction of the Kalman filter enables the state estimation of waveform domain signals. Additionally, valid and invalid integral elements are discriminated within the waveform domain signals via adaptive threshold detection, and a state space estimation is formulated, specifically concerning the valid integral elements. In conclusion, by suppressing the invalid integral elements within the waveform domain signals, the proposed approach simultaneously supplements the estimated state space of valid integral elements with their corresponding length components. This preservation of residual valid integral elements, coupled with integration operation, yields a range profile outcome devoid of deceptive interference artifacts. Importantly, the approach proposed herein operates independently of any prior information regarding the interference device parameters, thereby substantially reducing the effect of ISRJ. Simulation experiments illustrate that, in comparison with traditional methodologies, the method proposed in this study exhibits remarkably superior resistance against the ISRJ interference challenges.