基于Legendre多项式展开的双基SAR二维频域成像算法

2D frequency domain imaging of bistatic SAR based on Legendre polynomial expansion

针对任意构型双基SAR基于传统Taylor级数展开斜距方法的边缘点散焦问题,提出了一种基于Legendre正交多项式逼近的双基SAR二维频域成像算法。该算法基于对斜距函数的Legendre多项式展开推导了点目标二维频谱,解除了回波信号距离—方位的耦合,使成像处理更高效。在二维频域对场景区域的点目标采用二维频域成像算法进行成像。该算法改善了场景边缘点的聚焦效果,增加了场景边缘点的聚焦深度。理论推导和仿真结果验证了该算法的有效性和可行性。

Aiming at the problem of edge point defocusing of arbitrary configuration bistatic SAR based on traditional Taylor series expansion slant range method,this paper developed a 2D frequency domain imaging algorithm based on Legendre orthogonal polynomial approximation.This algorithm derived the 2D spectrum of the point target based on the Legendre polynomial expansion of the slant range function,which eliminated the coupling of range and azimuth of the echo signal and made the imaging processing more efficient.2D frequency domain imaging algorithm imaged the point target of scene region in 2D frequency domain.The algorithm improved the focusing effect of scene edge points and increased the focusing depth of scene edge points.The theoretical derivation and simulation results verify the effectiveness and feasibility of the proposed algorithm.