Anti-interference methods for narrowband and repeater-modulation interference in airborne SAR systems

Abstract

With the advancement of electronic countermeasures, airborne synthetic aperture radar (SAR) systems are facing increasing challenges in maintaining effective performance in hostile environments. In particular, high-power interference can severely degrade SAR imaging and signal processing, often rendering target detection impossible. This highlights the urgent need for robust anti-interference solutions in both the signal processing and image processing domains. While current methods address interference across various domains, techniques such as waveform modification and spatial filtering typically increase the system costs and complexity. To overcome these limitations, we propose a novel approach that leverages the multi-domain characteristics of interference to efficiently suppress narrowband interference and repeater modulation interference. Specifically, narrowband interference is mitigated using notch filtering, a signal processing technique that effectively filters out unwanted frequencies, while repeater modulation interference is addressed through strong signal amplitude normalization, which enhances both the signal and image processing quality. These methods were validated through tests on real SAR data, demonstrating significant improvements in the imaging performance and system robustness. Our approach offers valuable insights for advancing anti-interference technologies in SAR systems and provides a cost-effective solution to enhance their resilience in complex electronic warfare environments.

Keywords

Airborne radar / Narrowband interference / Repeater modulation interference / Signal and image processing anti-interference

CRediT authorship contribution statement

Kai Chen: Conceptualization, Methodology, Writing – original draft. Yong-Bo Zhao: Supervision, Writing – review & editing. Kai Jiang: Methodology, Validation, Writing – original draft. Long Sun: Methodology. Kun Deng: Data curation. Chang-Chun Ding: Visualization.

Declaration of competing interest

The authors declare the following personal relationship which may be considered as competing interests: Long Sunis currently employed by at Sun Create Electronics Co. Ltd. Other authors declare that there are no competing interests.

Acknowledgement

Special acknowledgment is extended to the interdisciplinary team at the 38th Research Institute of China Electronics Technology Group Corporation (CETC-38) for their collaborative effort.

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