抛物方程法在森林环境电波传播特性预测中的应用

摘要

为提高大区域森林环境电波传播特性预测的准确性,研究抛物方程(PE)法在森林环境电波传播特性预测中的应用,提出了基于抛物方程的森林模型.该模型采用PE法实现准确快速求解,考虑森林在垂直方向上的非均匀性,引入森林分层模型,将森林分为树冠、树干两个均匀有耗介质层,并根据森林区域的特性参数确定各有耗介质层的等效介电常数,相比于传统将森林等效为一个给定介电常数的均匀有耗介质层,能够更准确地描述森林对电波传播的影响.将其应用于三种常见绿叶林的电波传播特性预测中,仿真结果表明,该模型能够反映不同区域、不同植被种类的森林对电波传播的影响差异,有效预测大区域森林环境电波传播特性.%The application of parabolic equation(PE) model for wave propagation in forest is researched. And the forest model based on PE is proposed to improve the accuracy of the wave propagation characteris-tics prediction in forest.PE is used to analyze this model for the accuracy and timeliness of the radio wave propagation.Considering the non-uniform distribution of forest in the vertical,the stratified model is intro-duced and forest is divided into canopy and trunk lossy dielectric layers,positioned between air and ground.The equivalent dielectric permittivity of each lossy layer is solved according to the feature parame-ters of forest.Compared with the traditional model which takes the forest as a uniform lossy layer with a giv-en equivalent dielectric permittivity,the new model can describe the effect of forest on wave propagation more correctly.The model is applied to predict the wave propagation in three kinds of common trees.Nu-merical simulations demonstrate this model can reflect the effect of the difference in domain and tree spe-cies,and can predict wave propagation loss in large domain forest environment effectively.