频谱外推技术在毫米波CSAR成像中的应用

Spectrum Extrapolation Technique Applied in Millimeter Wave CSAR Imaging

近年来圆轨迹合成孔径成像(CSAR)成为SAR成像领域的一个研究热点,同时超分辨频谱外推技术能够有效改善SAR图像的聚焦质量。针对频谱外推技术在近场毫米波CSAR柱面成像中的应用进行了研究,将频谱外推算法与传统的波数域算法相结合,旨在提升SAR图像的聚焦效果;仿真点目标结果表明基于频谱外推技术的改进算法可以明显改善点目标的分辨率、峰值旁瓣比、积分旁瓣比指标;在室内基于矢量网络分析仪与高精度转台搭建了近场测量系统获得实测回波数据,通过雷尼熵评价指标衡量成像结果,结果表明基于频谱外推技术的改进算法成像结果优于传统成像算法的结果。

In recent years,circular synthetic aperture imaging(CSAR)has become a research hotspot in the field of SAR imaging.At the same time,the super resolution spectrum extrapolation technology can effectively improve the focusing quality of SAR images.In this paper,the application of spectrum extrapolation technology in the near field millimeter wave CSAR cylindrical imaging is studied.The spectral extrapolation algorithm is combined with the traditional wavenumber domain algorithm to improve the focusing quality of the SAR image.Simulation point target results show that the improved algorithm based on spectrum extrapolation can significantly improve the resolution,peak sidelobe ratio and integral sidelobe ratio.The real data is obtained in the near field measurement system based on the vector network analyzer and the high precision turntable,and the results of the imaging are measured by the Rani entropy.The results show that the improved algorithm is better than the traditional imaging algorithm.