摘要
该文针对周期性变PRF采样高分辨率聚束模式合成孔径雷达(SAR)提出了一种改进的两步成像算法。变脉冲重复频率(PRF)设计可解决固定盲区等问题,是解决星载SAR高分宽幅矛盾的一种有效手段,但变PRF采样会引起频谱混叠和虚假目标等问题。该文从离散非均匀傅里叶变换原理出发,推导改进sinc插值核函数并建立了时域-时域的回波重建方法,将变PRF采样回波重构为均匀采样回波。此外将改进sinc插值与两步式成像算法结合,据此发展出针对非均匀采样回波的改进两步式聚束SAR成像算法,拓展了传统两步式成像算法的使用范围。仿真数据和实际数据处理结果验证了成像算法的有效性和精确性,并且改进sinc插值具备更高的计算效率。
This paper focuses on an improved imaging-algorithm for the spotlight Synthetic Aperture Radar (spotlight SAR) with continuous Pulse Repetition Frequency (PRF) variation in extremely high-resolution imaging-process. PRI variation is conventionally employed to resolve the problem of fixed blind ranges as well as the conflict of high-resolution and wide-swath;however, there are problems such as spectrum aliasing and ambiguous targets caused by nonuniform sampling. In this study, a novel sinc interpolation method is proposed to reconstruct a uniformly sampled signal from non-uniform Fourier Transform samples. Then a two-step processing approach combined with the novel sinc interpolation method is presented in the process of nonuniformly sampled echo imaging. The simulation proves the validity and accuracy of the proposed imaging algorithm. In addition, the computational cost of the novel sinc interpolation is further reduced compared to that of non-uniform Fourier transformation.
作者
陈世阳
黄丽佳
俞雷
CHEN Shiyang;HUANG Lijia;YU Lei(Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China;Key Laboratory of Technology in Geo-Spatial Information Processing and Application System, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China;School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;School of Electronics and Information Engineering, Beihang University, Beijing 100191, China)
出处
《雷达学报（中英文）》
CSCD
北大核心
2019年第4期527-536,共10页
Journal of Radars
基金
国家自然科学基金(61331017)~~
