黄渤海地区大气折射环境参数统计分析

Statistical Analysis of Atmospheric Refraction Environmental Parameters at Yellow Sea and Bohai Sea Region

大气折射环境显著影响微波、超短波无线电装备的性能,能够减小或者扩展标准大气环境下的无线电视距。文中以黄渤海交界处的荣成为例,基于2018年探空数据统计分析了荣成站的大气折射环境参数,包括地面折射率、1 km折射率梯度、100 m折射率梯度等参数。其中,地面折射率年度变化范围可达100 N单位,地面折射率年平均值为332.3 N单位;1 km折射率梯度年平均值为-48.5 N/km;100 m折射率梯度年平均值为-44.2 N/km,100 m折射率梯度小于-100 N/km的时间概率为3%。进一步地,文中给出了计算雷达视距需要用到的等效地球半径因子以及用于表征相对标准大气无线电视距的扩展或减小的视距因子分布。结果表明:等效地球半径因子最大可达4.5;相对标准大气环境下,大气折射环境对视距影响的最大变化范围可达80%以上。研究结果可为黄渤海地区试验装备的系统设计、性能评估提供大气折射环境参考。

The atmospheric refraction environment significantly affects the performance of microwave and ultra-short wave radio equipment,which can reduce or increase the radio horizon of radio equipment in standard atmospheric environment.Taking Rongcheng at the junction of Yellow Sea and Bohai Sea as an example,based on the radiosonde data in 2018,the atmospheric refractive environment parameters of Rongcheng Station are statistically analyzed,including ground refractivity,1 km refractivity gradient,100 m refractivity gradient and other parameters.The annual variation range of ground refractivity can reach 100 N units.The annual average ground refractivity is 332.3 N units.The annual average refractivity gradient of 1 km is-48.5 N/km,the annual average refractivity gradient of 100 m is-44.2 N/km,the time probability of 100 m refractivity gradient less than-100 N/km is 3%.Furthermore,the equivalent earth radius factor used for radar horizon calculation and the distribution of radio horizon factor characterizing the expansion or reduction of relative standard atmosphere condition are given.The results show that the maximum equivalent earth radius factor is 4.5.Compared with standard atmospheric environment,the maximum change of atmospheric refraction environment on radio horizon can reach more than 80%.These results can provide reference for the system design and performance evaluation of the test equipment in the Yellow Sea and Bohai Sea.