粗糙海面与其上方多目标复合散射的混合算法

摘要

针对粗糙海面与其上方多目标复合的情形,常用算法存在计算量过大、计算时间太长等缺点,本文采用基尔霍夫近似法与矩量法结合的混合算法可以大大简化计算量、节省时间.本文首先通过蒙特卡罗的方法模拟一维PM粗糙海面,并与粗糙海面上方多目标建立复合模型;然后对矩量法结合基尔霍夫近似法的混合算法做了详细的公式推导,得到了复合散射系数,并且分析了不同入射角、目标高度、目标间距、目标尺寸、风速等参数对复合电磁散射特性的影响.实验结果表明,针对粗糙海面与其上方多目标复合的情形,采用矩量法结合基尔霍夫近似法的混合算法不但可以保证准确性,而且可以大幅度减少计算所用时间(混合算法用时占矩量法的19%),对大尺寸粗糙面和复杂的复合模型优势尤为明显.%In the study of electromagnetic scattering of multi-target composite on and above the rough sea surface, the common algorithm such as the method of moment analyzes the relationship between the target and the rough sea surface point by point, so the common algorithm usually requires massive computation and a lot of time. In this paper, the rough sea surface is described by Pierson-Moscowitz (PM) spectrum and Monte Carlo method, and the composite electromagnetic scattering from multiple conductor flying targets above the rough sea surface is investigated by using the hybrid algorithm-the method of moment in the Kirchhoff approximation. The composite scattering region is divided into target region and rough sea surface region. The target region and the rough sea surface region are investigated by using the method of moment, and the Kirchhoff approximation, respectively. The formulas of the hybrid algorithm in different polarizations are derived in detail, and the scattering coeffifficients in different incident angles, target heights, target sizes, target distances and wind velocities are calculated in detail. The characteristics of the composite scattering coefficient from the multiple conductor flying target above the rough sea surface are also obtained. Results show that the hybrid algorithm, i. e., the combination of method of moment and the Kirchhoff approximation, can obtain higher accuracy, and reduce the computation time efficiently. The computation time used by the hybrid algorithm is 19% of that by using the method of moment. Moreover, the performance becomes more favorable with the increase of size of rough sea surface.