复杂环境地区电波折射修正中的折射率精确获取方法

雷达电波射线上大气折射率的准确性是提高电波折射误差修正精度的关键因素之一.对下垫面复杂地区的雷达系统,常用的大气球面分层法因没有考虑大气水平方向变化使得电波射线上的折射率具有较大的误差,从而影响了电波折射误差修正精度.针对下垫面复杂地区的三维大气结构,提出了获得电波射线上大气折射率的组合方法,即在雷达所在地采用直接探测法,在其他电波射线上,先计算出射线点的位置,然后再利用已建立的全国大气剖面模型数据库得到该位置的大气折射率,从而较为精确地获得电波射线上的大气折射率.经实验验证,采用组合法获得的电波射线上的折射率不仅具有较好的精度,而且可有效地提高电波折射误差修正精度,进而提高下垫面复杂地区的雷达探测精度.

A method for accurately obtaining refractive index of radio wave refraction correction in complex environment

The accuracy of atmospheric refractive index on radar wave is one of the key factors to improve the of correction accuracy of radio wave refraction error.For radar systems in complex areas of underlying surface,the atmospheric spherical stratification method does not take the variation of horizontal direction of atmosphere into account,which makes the refractive index of radio wave ray have a large error,thus affecting the correction accuracy of radio wave refraction error.In view of the three-dimensional atmospheric structure in the complex area of the underlying surface,a combined method for obtaining the atmospheric refractive index on the radio wave ray is proposed,that is,the direct detection method is used in the radar location,and the position of the ray point is first calculated on the other radio wave rays.Then the atmospheric refractive index of this position is obtained by using the established national atmospheric profile model database,and the atmospheric refractive index on the radio wave ray is obtained more accurately.It is verified by experiments that the refractive index obtained by the combination method not only has better accuracy,but also can effectively improve the correction accuracy of the radio wave refraction error,and then improve the radar detection accuracy in the complex area of the underlying surface.