海洋环境对雷达海杂波后向散射特性影响分析

Analysis of the impact of oceanic environment on radar clutter backscatter characteristics

为分析海洋环境对雷达海杂波后向散射特性的影响,建立了一种基于修正复合模型方法的雷达海杂波后向散射关系模型。雷达入射余角较大时,主要散射形式为镜面散射;入射余角较小时,主要散射形式为Bragg散射。考虑了逆顺风条件下后向散射系数的差异性,改进了原有模型Bragg散射的方向海谱部分,增加了风向因子。利用模型对不同入射角条件下海洋环境因素与后向散射系数的关系进行了仿真计算。计算结果表明,当海面作为雷达波的反射面时,雷达后向散射特性十分复杂,风速、风向、海浪、降水、海面油污等海洋环境因素都会对其产生影响。其中,风速和有效波高对海面后向散射的影响最大,风向次之,降水再次之,而海面油污的影响最小。

A relational backscattering coefficient model based on the modified composite sea clutter model has been built in order to analyze the impact of oceanic environment on radar backscattering characteristics.The main scattering form is specular return under the high-grazing angle condition,and Bragg scattering under the low-grazing angle condition.Improvements have been made in the directional ocean wave spectrum part of Bragg scattering,considering the difference of backscattering coefficient between upwind and downwind conditions.With the model,simulation has been made in different incident conditions.The results indicate that the characteristics of radar backscatter would be very sophisticated when the sea surface is involved.Oceanic factors like wind speed,wind direction,waves,rainfall,slick can have some effects on the backscattering coefficient.Furthermore,wind speed and significant wave height both have the largest effect on backscattering coefficient,and wind direction takes second place,then rainfall,and slick is the least influential factor listed here.