不规则地形条件下的双向抛物方程模型研究

摘要

Based on the conventional split-step Fourier transform (SSFT) , the recursive two-way parabolic equation ( TWPE) modeling is presented for the problems of former algorithms' deficiencies and computational error. The traditional algorithms forecast only forward-propagating waves and neglect the backward-propagating waves, which causes greater error in the presence of irregular terrain boundary environment. The new algorithm enhances the computation accuracy and remedies the insufficiencies by the recursive two-way split-step method. Compared to traditional wide-angle parabolic equation (WAPE) and geometrical theory of diffraction (CTD) , the correctness and applicability of the model are verified by simulation results in the complex environment including single knife-edge, double knife-edges and real terrain.%在传统SSFT抛物方程模型基础上,针对传统算法忽略电波后向传播与散射,造成不规则地表边界条件下电波传播预测误差较大的问题,提出了可计算任意不规则地形剖面下前向和后向传播场的递归双向抛物方程模型,并给出了具体实现步骤,提高精度的同时弥补了传统算法的不足.仿真分析了双向抛物方程模型计算标准大气条件下单刃峰、双刃峰及实际地形的电波传播场分布特性,并与传统宽角抛物方程与几何绕射理论进行比较,验证了算法及模型的正确性与有效性.