天波超视距雷达海面风向提取技术  

Extraction of Ocean Surface Wind Direction with Sky Wave Over-the-horizon Radar

作　　者：孙明磊[1] 邵学德[1] 贺承杰[1] SUN Ming-lei;SHAO Xue-de;HE Cheng-jie(The 27th Hesearch Institute oectronics Technology Group Corporation, Zhengzhou 450047, Chin)

机构地区：[1]中国电子科技集团公司第二十七研究所,郑州450047

出　　处：《电光系统》2018年第1期12-20,28,共10页Electronic and Electro-optical Systems

摘　　要：天波超视距雷达利用电离层对高频电磁波（3～30MHz）的反射原理，可对空中目标和海面目标进行超视距检测和跟踪，探测距离可达3000km。除军事应用外，天波超视距雷达还具有独特的海洋遥感能力。为了分析利用天波超视距雷达进行海面风向反演的可行性，本文首先分析了一阶和二阶海面后向散射回波的产生机理。同时，通过利用相邻两个波束的海面风向缓慢变化信息，研究了一种无模糊的海面风向反演算法。仿真试验表明，正、负一阶Bragg峰回波能量的相对比值受海面风向影响，基于数字波束形成技术，将该方法依次应用于雷达覆盖范围内的各检测单元，即可得到大区域的海面风向分布信息。研究结果表明，天波超视距雷达可发展成为一种有效的海面风向遥感监测手段。Sky-wave over-the-horizon （OTH） radars track airborne and surface targets beyond the visible exploit signal reflection from the ionosphere to detect and horizon, which operates in the high frequency band （3- 30 MHz）, and the overall potential coverage could nominally extends 3000 km in range. In addition to such military uses, it provides a unique ocean remote sensing capability. In this paper, the scattering mechanism of the first-and second-order sea echoes back scattered from the ocean surface are studied to investigate the feasi- bility of extracting wind direction. Meanwhile, an algorithm of extracting wind direction without ambiguity is presented, where the ambiguity is resolved by minimizing the difference among the indeterminate wind directions derived from two adjacent radar look angles. The simulation results reveal that the ratio of the strength of the positive and negative peaks is highly sensitive to the wind direction, and the unambiguous wind directions of the large sea area covered by radar can be obtained by applying the method proposed sequentially to the whole field of view of the radar with digital beam forming （DBF）. It is shown that sky wave over-the-horizon radar would become a useful tool for remotely sensing oceanic winds.

关 键 词：天波超视距雷达 海面回波多谱勒谱 海面散射截面积 海面风向 Bragg峰 数字波束形成 

分 类 号：TN958.93[电子电信—信号与信息处理]