后向投影(back projection,BP)成像算法能够适应非均匀孔径,但是其运算效率过低限制了其工程应用。很多学者基于子孔径划分的原理提出了不少改进的快速后向投影(fast back projection,FBP)算法,但是目前对于子孔径划分后如何进行运动补偿还未有深入研究。就不同的运动情况对FBP算法的运动补偿进行了研究,包括最简单的仅有方位向误差的直线运动补偿,同时存在方位向和距离向运动误差的情况,到存在有意机动的曲线航迹,最后提出了一套完整的基于传感器测量的任意孔径快速后向投影成像算法。实测数据处理结果证明了所提的算法能够适应不同运动情况进行快速成像。
Back projection(BP) imaging algorithm,whose low efficiency reduces its applications in practical projects,could be applied in non-uniform apertures.According to this,many scholars have presented some fast back projection(FBP) algorithms based on the sub-aperture method.But how to compensate the motion error after sub-aperture dividing is awaited for further studying.The motion compensation method for FBP algorithm at different motion error levels is studied.Three situations denoting different motion error levels,which are only non-uniform azimuth aperture,tracks of two-dimensional motion error and highly nonlinear even curvilinear flight tracks,are discussed.Then an FBP projection imaging algorithm for arbitrary aperture is given,and this algorithm needs highly precise position information.Finally,an outside experiment is made to prove the algorithm's availability.