基于双向有限差分抛物方程法的海洋环境电波传播研究

Radio wave propagation in complex sea environment based on two-way parabolic equation method

采用双向抛物方程(two-way parabolic equation,2WPE)法来预测复杂海洋环境中的电波传播特性,用双向有限差分(two-way finite-difference,2WFD)法求解2WPE,考虑了海岛等不规则地形引起的电波后向传播和大气波导的影响,并在前向和后向电波传播预测中引入一种改进的分形海面模型来模拟起伏波动的实际海面边界,且能模拟海面的大尺度浪涌特性和毛细波细微结构特性.在典型的数值算例中,我们将采用改进分形模型处理海面边界时计算得到的双向电波传播因子和采用Miller-Brown模型处理海面边界时计算得到的双向电波传播因子进行对比和分析,数值分析结果表明,在相同风速条件下,采用改进分形模型处理海面边界时计算得到的双向电波传播因子波动更剧烈,能更准确地反映出实际起伏波动海面对电磁波传播的影响.

In this paper the two-way parabolic equation(2WPE)is used to predict the propagation characteristics of electromagnetic waves in complex sea environments,and the two-way finite-difference(2WFD)method is used to solve the 2WPE.The effects of backward electromagnetic waves caused by irregular terrain such as islands and the influence of atmospheric duct on electromagnetic waves are considered.An improved fractal sea surface model is introduced in the prediction of forward and backward wave propagation to simulate the actual sea surface boundary.This model can simulate characteristics of the large-scale surge and capillary of the sea surface.The two way propagation factors calculated by improved fractal sea surface model are compared with those calculated by the Miller-Brown model.The numerical simulation results show that under the same wind speed condition,the two-dimensional electric wave propagation factor calculated by using the improved fractal model to deal with the sea surface boundary is more severe,which can more accurately reflect the influence of the actual undulating sea on the electromagnetic wave propagation.