Parabolic equation based land clutter power map modeling for low-altitude surveillance radar in urban areas
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摘要:
地杂波强度是影响雷达低空空域监测性能的重要因素之一。尤其在城市环境下,高层建筑和大气结构将使雷达信号传播及地表电磁散射特性产生复杂变化。提出一种基于抛物方程(PE)的城市环境地杂波强度分布建模方法,能够为低空空域监测雷达系统性能预估、站址选择和杂波特性分析提供理论基础。首先,通过宽角PE模型,预测城市高层建筑及大气结构引起的雷达信号反射、绕射、折射和多径效应;其次,将宽角PE模型扩展到三维空间,结合雷达方程,实现各杂波单元的强度计算;最后,利用仿真结果分析了不同建筑外形和高层建筑群对雷达信号传播和地杂波强度的影响。
Abstract:Land clutter power exerts a strong impact on the performance of low-altitude surveillance radar. Especially in urban areas, skyscrapers and atmosphere conditions complicate the radar signal propagation and the electromagnetic scattering from land surfaces. This paper presents a land clutter power map modeling approach for low-altitude surveillance radar in urban areas by using the parabolic equations (PE). It could theoretically contribute to the performance prediction and field deployment of such radar systems as well as the analysis of urban clutter characteristics. The proposed approach exploits wide-angle PE to take into account the reflection, diffraction, refraction and multipath effects in low-grazing-angle radar propagation related to tall buildings and atmosphere conditions. After the 3D approximation of aforementioned 2D wide-angle PE, the propagation factors could be obtained in the 3D environment. Then according to the radar equation, the power in every clutter cell is calculated. Finally, numerical simulations are carried out to demonstrate the influence of different architectural appearances and urban skyscrapers on radar signal propagation and land clutter powers.
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