基于Legendre展开的双基地SAR点目标频谱推导

双/多基地合成孔径雷达二维点目标频谱的求解是各种频域成像算法的基础，但斜距表达式中的双根号使得直接精确解析求解非常困难。本文从函数最佳逼近这一全新角度出发，提出了基于Legendre正交展开的双基地SAR回波二维谱的解析求解方法，得到了比现有方法更为精确的二维频谱。 

Point Target Spectra Derived for Bistatic SAR Processing Based on Legendre Polynomial Expansion

The formulation of a point target spectrum is a key step in deriving synthetic aperture radar focusing algorithms, which exploits the processing efficiency of the frequency domain. However, the existence of a double-square-root (DSR) in the bistatic range equation makes it difficult to find an exact analytical solution for the 2-D spectrum. In this paper, according to the idea of function optimal approach, we derive a new 2-D point target spectrum on the basis of Legendre polynomial expansion, which is more exact than the existing spectrums during the synthetic aperture time.