对流层折射修正中水汽压公式对比研究

Comparison of Water Vapor Pressure Formulas Used in Tropospheric Refraction Correction

针对当前对流层大气折射效应评估计算的工程应用中,水汽压的计算方法不尽统一、精度参差不齐的现状,分别在-50℃～0℃气温范围内利用各平冰面饱和水汽压公式、在0℃～50℃气温范围内利用各平液面饱和水汽压公式对大气折射率湿项进行了仿真计算,通过对仿真结果的比较可知：在平冰面和平液面情况下,Buck（巴克）1981公式和Buck1996公式与Goff-Gratch（戈夫-格雷奇）公式的偏差均较小,计算精度较高,建议作为测控系统外测数据处理中大气折射修正的首选经验公式;该分析结果也可为其他需要考虑水汽影响的工程领域提供参考.

There are numerous types of water vapor formulas in evaluation of atmospheric refraction error and their precision varies from each other.To choose a higher precision formula for calculation of water vapor pressure,wet refractivity computed by water vapor pressure formulas over ice between-50℃ and 0℃ and liquid water between 0° C and 50℃ is simulated and compared in this paper.The results show that Buck1981 formulas and Buck1996 formu las are more consistent with Goff-Gratch formulas both over ice and over liquid water and they should be the better choices of empirical formulas in data processing of trajectory measurement for TT＆C （Telemetry,Tracking and Command） systems.The findings provide valuable reference for other engineering fields concerned with the effect of water vapor pressure.