中文摘要：

首先,从SAR成像角度重新推导了MWD算法,新推导方法更好地阐述了MWD算法的两维分离聚焦成像原理,并使该算法在形式上能够和其它频域算法保持一致,以便于不同频域算法间的比较分析。其次,基于文中所给的MWD算法和NCS算法成像流程,研究了两种算法对低频UWB SAR的成像性能。此外,通过评估浮点运算量,对比分析了两种算法的成像效率。最后,仿真和实测数据成像结果证明了理论分析的正确性。

英文摘要：

First,a new derivation of the modified wavenumber domain（MWD）algorithm from the viewpoint of synthetic aperture radar（SAR）imaging is presented in this paper.The proposed derivation has better explanation on the imaging principle of the two dimensional separated focusing of the MWD algorithm.Since this new derivation is consistent with the other frequency algorithms,it is easy to carry out comparison analysis between the MWD algorithm and other frequency algorithms.Second,the performances of the two algorithms for processing low frequency ultra-wide band SAR（UWB SAR）data are studied based on the imaging processing flow charts of the MWD algorithm and NCS algorithm.Then,imaging efficiencies of the two algorithms are compared by evaluating their floating computation load.At last,the imaging results with simulated and real data prove the effectiveness of the theory analysis.