CAJ | 학술논문

一站固定式双基地低频UWB SAR具有方位移变的距离徙动和较长的合成孔径，这导致其距离方位耦合变得非常复杂，从而限制了频域算法的应用。为此，本文提出一种基于椭圆极坐标的一站固定式双基地低频UWB SAR FFBP算法。基于一站固定式双基地SAR的成像几何，分别推导了直角坐标与椭圆极坐标下后向投影算法的解析表达式，并讨论了双基地FFBP算法中采用椭圆极坐标的优势。然后分别从频带和斜距误差角度推导了子图像的采样间隔。最后讨论了该算法的实现过程和计算量。仿真结果证明了所提方法的有效性。
일참고정식쌍기지저빈UWB SAR구유방위이변적거리사동화교장적합성공경，저도치기거리방위우합변득비상복잡，종이한제료빈역산법적응용。위차，본문제출일충기우타원겁좌표적일참고정식쌍기지저빈UWB SAR FFBP산법。기우일참고정식쌍기지SAR적성상궤하，분별추도료직각좌표여타원겁좌표하후향투영산법적해석표체식，병토론료쌍기지FFBP산법중채용타원겁좌표적우세。연후분별종빈대화사거오차각도추도료자도상적채양간격。최후토론료해산법적실현과정화계산량。방진결과증명료소제방법적유효성。
One-stationary bistatic low frequency ultra wide band synthetic aperture radar (UWB SAR) has the azimuth-vari-ant range cell migration and longer synthetic aperture ,which greatly complicates the range-azimuth coupling and limits the applica-tion of frequency-domain algorithms .In this paper ,a fast factorized back projection (FFBP ) algorithm based on elliptical polar coor-dinate is presented to focus the one -stationary bistatic low frequency UWB SAR data .Based on the imaging geometry ,the analyti-cal expressions of the back projection (BP) algorithm in Cartesian coordinate and elliptical polar coordinate systems are derived ,re-spectively .The advantage of implementing the bistatic FFBP algorithm in elliptical polar coordinate is analyzed .Then ,the sampling requirements for subimages are deduced from the bandwidth and bistatic range error angles ,respectively .Finally ,the implementation and the computational burden of this algorithm are discussed .Simulation results prove the validity of the proposed approach .