目标后向散射RCS基于MBPE均匀采样的快速计算

根据目标后向散射RCS的计算特点,提出空、频两域的MBPE均匀采样方案.在空间域,提出基于球面波角谱空间展开的宽角度采样方案;在频率域,考虑到在相同角度下观测到的目标会在不同频段下表现出相似的结构特征,提出先在低频段上训练不同入射角下的采样经验,然后再在高频段上进行MBPE插值计算.数值结果表明,在空间域,MBPE的采样点数一般仅为快速多极子采样点数的1/2,并随插值角度范围的缩小而减少;在频率域,MBPE采样点数与频率最大值无关,仅随扫频范围的增大而缓慢增加. 

Fast Calculation of the Monostatic RCS by the Objects Based on MBPE Technique with Equispace Sampling

It is difficult to select sampling point exactly when the model based parameter estimation(MBPE) method was used to interpolate the monostatic radar cross section(RCS) by the objects in the wide frequency span and wide angle span, especially when the curve shapes of the monostatic RCS fluctuate intensively. Although the adaptive method can solve this problem, it needs to get the exact numerical value of the relative points in advance and it is difficult to be parallelized. By contrast, the uniform sampling method is easy to parallelize, but the sampling scheme should be known at first. In this paper, based on the computation of the monostatic RCS by the objects, the sampling point selections schemes for MBPE interpolation in spatial domain and in frequency domain were proposed. In spatial domain, the sampling points were located along with the sphere wave directions. In frequency domain, depending on the similarity of the RCS's characteristics by the same objects, the sampling experiments were firstly detected in the low frequency, and then were used to calculate the monostatic RCS in the high frequency.Numerical experiments show that in spatial domain, the sampling points of MBPE are only half of sampling points of the fast multipole method(FMM) and will decrease with the narrowing of the angle's scope; in frequency domain, the amount of the MBPE sampling is independent of the maximum frequency, only slowly increases with increasing sweep range.