摘要
圆迹SAR(CSAR)因其特殊曲线运动轨迹而具备3维成像能力。单圈CSAR理论上可以获得距离方位平面亚波长级的分辨率,但是高程向分辨率却很低。同时,利用后向投影(BP)算法进行CSAR 3维成像的算法复杂度高,成像效率低。该文提出一种基于改进3维后向投影的多圈CSAR相干3维成像方法,针对现有成像算法时间复杂度高的问题,提出一种构造几何插值核的CSAR改进3维后向投影算法,可将3维插值操作转化为1维插值操作和距离向量搜索操作,通过多圈CSAR改进3维后向投影成像结果相干积累的方式得到最终3维图像。该文所提方法可有效解决单圈CSAR 3维成像高程向分辨率低的问题,改善3维成像细节,同时能够大幅降低CSAR 3维成像时间。仿真圆锥目标和美国空军实验室GOTCHA数据3维成像结果验证了该文所提方法的有效性。
Circular SAR(CSAR)has the ability of 3-D imaging due to its special curve trajectory.Single-pass CSAR can theoretically obtain the resolution of the sub-wavelength level on the distance-azimuth plane,but its resolution at the elevation direction is very low.At the same time,CSAR 3-D imaging with Back Projection(BP)has high algorithm complexity and low imaging efficiency.A coherent 3-D imaging method for multi-circular SAR based on an improved 3-D back projection algorithm is proposed.For the problem of high time complexity of the imaging algorithm,an improved 3-D BP algorithm for CSAR based on constructing geometric interpolation kernel is proposed.3-D interpolation operations are transformed into 1-D interpolation operations and distance vector searching operations.The final imaging result is obtained by coherently accumulating the improved 3-D BP results of multi-circular SAR.The proposed method solves effectively the problem of low elevation resolution of single-pass CSAR,improves 3-D imaging details,and reduces greatly the time of CSAR 3-D imaging simultaneously.The simulated 3-D imaging results of the conical target and GOTCHA data set from the US Air Force Laboratory verify the effectiveness of the proposed method.
作者
韩冬
周良将
焦泽坤
吴一戎
HAN Dong;ZHOU Liangjiang;JIAO Zekun;WU Yirong(Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100190,China;National Key Laboratory of Science and Technology on Microwave Imaging,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《电子与信息学报》
EI
CSCD
北大核心
2021年第1期131-137,共7页
Journal of Electronics & Information Technology
关键词
圆迹SAR
多圈CSAR
相干3维成像
改进3维后向投影算法
几何插值核
Circular SAR(CSAR)
Multi-circular SAR
Coherent 3-D imaging
Improved 3-D Back Projection(BP)algorithm
Geometric interpolation kernel
