【摘要】 与传统的直线SAR相比,圆周SAR(CSAR)具有对场景进行三维成像的能力,但对于一般的目标,其有效孔径只是一定角度的圆弧而非完整圆周孔径,使得圆周SAR只能获得航迹向和斜距向的高分辨率,影响了其三维成像能力,所以现在通常采用沿着不同高度角进行多次观测的多航过圆周SAR模式来实现三维成像。针对多航过圆周SAR由于多航过稀疏并且非均匀采样而严重影响成像质量的问题,提出一种将BP算法和压缩传感算法(CS)结合的三维成像算法。该算法先利用BP算法实现每一次航过数据的二维成像,再利用压缩传感算法进行高度向聚焦,来改善高度向的聚焦质量,最后将实测数据成像结果和传统的三维BP算法的结果进行比较,证明该算法可以有效地抑制旁瓣,得到超分辨的三维成像结果。更多还原

【Abstract】 The Circular Synthetic Aperture Radar(CSAR),unlike the linear SAR,has the capability to extract three-dimensional imaging information of a target scene.Its effective aperture is not the whole circular aperture but an arc for general target.This causes CSAR to only own the high resolution of along-track direction and slant-range direction,and the three dimension imaging ability is weak,so multi-pass CSAR is adopted to realize three dimensional target construction.According to the problem that multi-pass CSAR usually has sparse and non-uniform elevation samples,this paper proposes a three-dimension image formation algorithm based on the combination of Back Projection(BP) and Compressed Sensing(CS).The algorithm first uses BP algorithm to realize the two-dimensional image of single-pass data,and then uses CS algorithm to focus height dimension,to improve the high quality of the focus.Finally the measured data with the proposed algorithm is compared with the results of the proposed algorithm and BP algorithm′s to prove that the proposed algorithm can effectively inhibit side-lobe and improve the resolution.更多还原