高精度大气折射率插值方法研究

Research on High-Precision Atmospheric Refractive Index Interpolation Method

高精度的电波折射误差修正是提高雷达探测精度的关键因素之一,而雷达电波射线上大气折射率的准确性又对电波折射修正精度具有很大影响。针对目前大气折射率的线性插值方法引起电波射线上折射率出现较大误差情形,根据大气折射率变化规律,提出了分段大气插值方法,即第一段大气采用线性插值方法,第二段大气采用指数插值方法。利用大气折射率实际探测数据对线性插值和分段插值两种方法得到的电波射线上折射率进行比较,证明了分段插值方法具有较高的精度;利用两种方法得到的大气折射率进行电波折射误差计算,经与雷达实际测量数据比较,证明了分段大气插值方法可有效地提高电波折射修正精度,进而可确保雷达的高精度探测。

High-precision correction of radio wave refraction error is one of the key factors for improving the accuracy of radar detection.The accuracy of atmospheric refractive index on radar radio wave ray has a great influence on the accuracy of radio wave refraction correction.In view of the fact that the current linear interpolation method of atmospheric refractive index causes a large error in the refractive index on the radio wave ray a piecewise atmospheric interpolation method is proposed according to the law of the variation of atmospheric refractive index in which the linear interpolation method is used on the first section of the atmosphere and the exponential interpolation method is employed on the second section of the atmosphere.The actual detected data of the atmospheric refractive index is used to compare the refractive indices on the radio wave ray obtained by linear interpolation and piecewise interpolation and it is proved that the piecewise interpolation method has higher accuracy.The atmospheric refractive index obtained by the two methods is used to calculate the radio wave refraction error.It is proved that the piecewise atmospheric interpolation method can effectively improve the accuracy of radio wave refraction correction and thus ensure the high-precision detection of the radar.