不同星历产品对GNSS可降水量的影响分析

Influence analysis of different ephemeris products on precipitable water vapor of GNSS

针对最终精密星历发布延迟时间长、更新速度慢,无法满足实时数值气象预报的需求的问题,提出利用超快速星历和快速星历替代最终精密星历反演全球卫星导航系统(GNSS)大气可降水量(PWV)的方法,并基于香港连续运行参考站(CORS)数据和国际GNSS服务中心(IGS)提供的星历产品,使用中国测绘科学研究院自研的高精度GNSS数据处理软件GPAS进行PWV反演实验。结果表明:3种方案反演的GNSS-PWV与探空数据计算的PWV具有较强的相关性,其中利用精密星历解算PWV精度最高,利用超快速预报星历的精度最低;3种方案的PWV之间的相关性较高,进一步证明了使用超快速预报星历代替最终精密星历进行PWV反演是可行的,能够满足实时气象预报的精度要求。

Aiming at the problem that the issue time is long and the updating speed is slow of final precise ephemeris,which cannot meet the requirement of real-time numerical weather forcasting,the paper proposed the inversion method of GNSS PWV by using ultra-rapid ephemeris and rapid ephemeris instead of the final precise ephemeris,and a PWV inversion test was carried out with the high-precise GNSS data processing software GPAS developed by the Chinese Academy of Surveying and Mapping,based on the observation data of CORS in Hong Kong and the ephemeris products provided by the International GNSS Service(IGS).Result showed that the GNSS-PWV inverted by the three schemes could have strong correlation with the PWV calculated by sounding data,among which the accuracy of PWV from precise ephemeris would be the highest,while that from ultra-fast prediction ephemeris would be the lowest;meanwhile the correlation of PWV between the three schemes would be high,which verified that it could be feasible to use the ultra-fast forecast ephemeris instead of the final precise ephemeris to perform PWV reversal,with an appropriate accuracy of real-time weather forecasting.