一种基于光学菲涅尔衍射理论的MLS场地环境电波散射研究新方法  

New Method of EM Scattering Computation of MLS Site Environment Based on Optical Fresnel Diffraction Theory

作　　者：戴传金[1] 吴德伟[1] 袁银勇[1] 何晶[1] 

机构地区：[1]空军工程大学电讯工程学院,西安710077

出　　处：《现代导航》2012年第4期261-267,共7页Modern Navigation

基　　金：国家自然科学基金支持

摘　　要：根据微波着陆系统场地环境电波散射的基本特性,提出了一种基于光学菲涅耳衍射理论的场地环境电波散射研究新方法。该方法通过将系统场地环境电波散射等价于天线镜像透过矩形孔菲涅耳衍射的方式,实现对非直达波相对直达波信号电平比计算。该方法的特点是对电波反射和电波绕射作统一处理,计算程序简化,运算量小。为验证所提方法的可行性,针对特定的机场场地环境,采用新方法与常用几何光学理论方法进行电波散射的仿真分析,并将仿真结果做了对比验证。结果表明:基于光学菲涅尔衍射理论的场地环境电波散射研究方法克服了几何光学理论在微波着陆系统场地环境电波散射计算过程中的使用缺陷和不足,且对于确定MLS场地环境电波散射影响程度具有一定的实用价值。A new method of EM-scattering computation of site environment based on Fresnel diffraction theory is presented as the essential features of MLS scattering. By the equivalent principle of the Fresnel diffraction through rectangular aperture to the EM scattering of site environment, the indirection relative to direction signals level ratio can be acquired. A unique property of this method is just coherently computing reflection and diffraction. The calculation procedures are simplified. Then, the computed load is further lower. To verify the feasibility and validity, the proposed method is applied to analyze the scattering characteristic in the specific site environment on the airport. Moreover, the results are compared with the calculation results using the common method based on the Geometrical Optical （GO） theory. Comparison of them shows the new method can overcome the limitation and deficiency of the common method in the scattering computation process. What＇s more, it has some practical values on determination of the extent of disturbance caused by site environment.

关 键 词：几何光学理论 菲涅耳衍射 电波散射 微波着陆系统 场地环境 

分 类 号：TN953[电子电信—信号与信息处理]