基于双层网格的海上电磁波传播模型研究

针对分段线性地形变换模型运算量较大的问题，该文提出基于双层网格的计算方法，实现了海上大尺度区域复杂电磁环境下电磁波传播特性快速精准的求解。在对宽角抛物方程模型和分段线性地形变换模型的分步傅里叶积分算法研究的基础上，将电磁场计算空间分为上下两层，通过降低计算高度和优化步长的方法，在保证计算精度的同时显著提高了运算效率。通过仿真，在光滑海面和粗糙海面两种条件下对双层网格模型的计算结果与原有模型进行比较，结果表明，所提方法计算误差较小，在粗糙海面条件下运算时间缩短到原模型的1/10。

Calculation of Electromagnetic Propagation Characteristics over Rough Sea Surface Based on Double-layer Model

A double-layer model is proposed to reduce the calculation amounts of the Linear Ship Map (LSM) model. The proposed model can be used for rapid and accurate calculation of the electromagnetic propagation characteristics in the complicated atmospheric environment over the sea. In the proposed model, the calculation regions are divided into the upper-layer and the lower-layer. The upper-layer is calculated by the Wide angle Parabolic Equation (WPE) model and the lower-layer is calculated by the LSM model. Through reducing the calculation height and optimizing the step length, the proposed model can be exact and rapid. By simulation, the proposed model is compared with LSM model in the smooth and the rough sea surface conditions. The results show that the proposed model can decrease the calculation time by 1/10 in the rough sea surface condition.