超快速精密星历反演大气可降水量的精度分析

Analysis of the accuracy of ultra-rapid precise ephemeris inversion of atmospheric precipitable water vapor

针对最终精密星历产出时延较长,无法满足实时反演大气可降水量的问题,基于加米特(GAMIT)软件,采用超快速精密星历(IGU)的24 h预报星历和最终精密星历(FPE),分别对中国香港地区2018年全年19个连续运行参考站(CORS)的大气可降水量(PWV)进行了反演解算,并结合实际降雨量,分析IGU星历对于PWV的反演精度。结果表明:IGU-PWV与探空数据(RAD)PWV相关系数达到了0.96,IGU-PWV与FPE-PWV相关系数达到0.99;IGU-PWV值与RAD-PWV全年均值相差为3.73 mm,在雨季二者相差4.98 mm,在非雨季二者相差2.49 mm,且全年IGU-PWV变化趋势基本与实际降雨量变化趋势一致。综合可知,IGU的24h预报星历能够满足实时探测大气可降水量的精度要求,可作为水汽探测的手段之一。

Aiming at the problem of long-time delay of the final precision ephemeris output for real-time inversion of precipitable water vapor, in this paper, based on GAMIT software, the Precipitable Water Vapor(PWV) inversion solutions of 19 Continuously Operating Reference Stations(CORS) in Hong Kong in 2018 were carried out using using ultra-rapid precise ephemeris(IGU) 24 h forecast ephemeris and Final Precision Ephemeris(FPE), respectively, to analyze the inversion accuracy of IGU ephemeris for PWV. The results show that: the correlation coefficients of IGU-PWV and radiosonde(RAD)-PWV reached 0.96, and the correlation coefficients of IGU-PWV and FPE-PWV reached 0.99;the difference between IGU-PWV values and RAD-PWV averages 3.73 mm throughout the year, the difference between the two in the rainy season was 4.98 mm,and the difference between the two in the non-rainy season was 2.49 mm, and the trend of IGU-PWV changes throughout the year was basically consistent with the trend of actual rainfall. In summary, the IGU 24 h forecast ephemeris can meet the accuracy requirements for real-time detection of atmospheric precipitable water vapor and is one of the means of water vapor detection.