基于SAR的HFPFM编码模型的高分辨率低侧叶波形设计
Yu Gao1, Guodong Jin1,2, Xifeng Zhang1
1Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211116, China.
Sensors (Basel, Switzerland)
|December 11, 2025
概括
本研究介绍了一种优化的高自由度参数化频率调制 (HFPFM) 波形,用于合成光圈雷达 (SAR) 系统. 新的波形显著减少侧叶,改善目标成像,而不牺牲分辨率或信号噪声比.
科学领域:
- 雷达系统工程 雷达系统工程
- 信号处理 信号处理
- 电磁学 电磁学 电磁学 电磁学
背景情况:
- 合成光圈雷达 (SAR) 传统上使用线性频率调制 (LFM) 波形.
- 使用LFM的窗口功能会降低信号噪声比 (SNR) 和用于侧叶抑制的分辨率.
- 非线性频率调制 (NLFM) 波形提供侧叶抑制,没有SNR损失,但仍然可能导致分辨率损失.
研究的目的:
- 为SAR系统开发先进的波形设计,克服LFM和NLFM的局限性.
- 为了优化雷达波形,增强侧叶抑制,而不影响主叶宽度,分辨率或SNR.
- 为波形优化引入一种新的高自由度参数化频率调制 (HFPFM) 编码模型.
主要方法:
- 基于HFPFM编码模型构建了一个波形侧叶优化模型.
- 在优化过程中应用约束来防止主叶扩大.
- 使用梯度下降方法解决了优化模型.
- 利用矩阵乘法和快速里叶变换 (FFT) /反向快速里叶变换 (IFFT) 进行高效的参数优化.
主要成果:
- 与LFM波形相比,优化的HFPFM波形实现了超过9dB的侧叶减小.
- 优化成功避免了大叶扩大,保持了分辨率.
- 该方法同时减轻了与窗口功能权重相关的分辨率和SNR损失.
- SAR点目标成像模拟表明,它能够清晰地图像强目标附近的弱目标.
结论:
- 提出的HFPFM波形优化方法有效地提高了SAR成像性能.
- 这种方法通过改善侧叶抑制并保持分辨率和SNR,为传统的LFM和NLFM波形提供了更好的替代方案.
- 优化的波形使复杂的目标能够更清晰地成像,证明了该方法的实际有效性.
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