基于级数反演的双基前视圆周SAR成像

Imaging for Bistatic Forward-Looking Circular SAR Based on Series Reversion Method

双基前视圆周合成孔径雷达(BFL-CSAR)为一种双基前视及圆周合成孔径雷达优势相结合的成像模式,拥有单基直线SAR及圆周SAR所不具备的前视二维成像优势。由于该构型双基距离历程双根号及三角函数的存在,其目标回波信号的二维频谱难以有效获得,从而给后续成像处理带来困难。针对这个问题,首先结合BFL-CSAR的运动特点,建立回波距离模型,利用级数反演理论有效获取了回波信号的二维频谱,并在此基础上提出了一种适用于双基前视圆周SAR的快速频域成像算法。计算机仿真实验验证了理论分析的正确性以及成像算法的有效性。

Combining the advantages of bistatic forward-looking synthetic aperture radar（SAR） and cir- cular SAR, the bistatic forward-looking circular SAR（BFL-CSAR） has some superiority in forward-looking two-dimensional（2-D） imaging capability over monostatic and circular SAR. It is difficult to efficiently obtain the 2-D frequency spectrum of the echo signal owing to the presence of double square root and trigonometric function in the range history, which brings about obstacles to the subsequent imaging. Thus, the bistatic range history is first built based on the motion characteristic of BFL-CSAR. And then 2-D frequency spec- trum is effectively gained by using series reversion method, followed by which a fast imaging algorithm in frequency domain for BFL-CSAR is proposed. Numerical experiments confirm the validity of theoretical anal- ysis and the effectiveness of our method.