SAR抗转发式干扰波形设计与优化

Design and optimization of SAR waveforms for countering re-radiation deception jamming

为提高合成孔径雷达(synthetic aperture radar,SAR)系统对抗转发式欺骗干扰的性能,提出一种基于非线性调频(non-linear frequency modulation,NLFM)信号的正交波形设计与优化技术,结合自主收发策略来优化波形组,使捷变发射的波形相互正交,从而达到在复杂环境下抑制转发式欺骗干扰的效果。首先,分析SAR系统转发式欺骗干扰的机理、波形捷变发射方法的合理性和有效性,提出利用正交波形设计进行抗干扰的方法;其次,采用S曲线法和分段函数法产生NLFM信号,基于拉格朗日算法,结合遗传算法对NLFM信号的波形组进行了优化设计;最后,通过仿真实验验证了本文方法设计的优化波形组在SAR系统中对抗转发式欺骗干扰的有效性。结果表明:由分段函数法产生NLFM波形后,在合适的干扰转发时延下,采用拉格朗日遗传算法优化NLFM波形的正交性,改善了波形的主瓣宽度和峰值旁瓣比,增强了捷变波形的正交性,提高了波形质量。

To enhance the capability of the synthetic aperture radar(SAR)system in anti-retransmission deception jamming,a technique for waveform design and optimization based on non-linear frequency modulation(NLFM)signals is proposed.This approach utilizes autonomous transmit-receive strategies to optimize waveform groups,ensuring that the waveforms emitted during agile transmission are mutually orthogonal.This enables effective suppression of retransmission deception jamming in complex environments.Firstly,the mechanism of retransmission deception jamming in SAR systems is analyzed,and the rationality and effectiveness of waveform agile transmission methods are discussed.A method for anti-jamming using orthogonal waveform design is then proposed.Secondly,NLFM signals are generated using the segmented function method,and the waveform group of NLFM signals is optimized based on the Lagrange algorithm in conjunction with the genetic algorithm.Finally,simulation experiments are conducted to verify the effectiveness of the optimized waveform set designed by the proposed method in countering retransmission deception jamming in SAR systems.The results show that when NLFM waveforms are generated by the segmented function method and optimized for orthogonality using the Lagrange genetic algorithm with appropriate jamming forwarding delays,they improve the mainlobe width and peak sidelobe ratio of the waveforms.This enhancement in orthogonality of agile waveforms leads to improved waveform quality.