基于超快速星历反演大气可降水量的精度分析

Precision analysis of atmospheric precipitation inversion based on super fast ephemeris

水汽是预报某些灾害性天气的重要依据,因此及时获得高分辨率的水汽产品对精准预报天气具有至关重要的意义.针对最终精密星历更新速度较慢、时延较长,无法满足实时反演大气可降水量的要求,提出一种利用超快速星历代替最终精密星历反演大气可降水量的方法:基于地基GNSS反演大气可降水量的原理,利用GAMIT软件,根据国际GNSS服务(IGS)网站提供的不同精度的星历产品获得大气可降水量,并与气象探空站所获得的大气可降水量对比分析.研究结果表明,利用超快速星历所获得的大气可将水量与最终精密星历一致,二者平均差值优于0.1mm,且与探空站测得的大气可降水量值非常一致,其精度可以满足天气预报的需求.

Water vapor is an important parameter for weather forecast weather,so it is important to obtain high resolution water vapor products in time. Aiming at the slow update speed and long delay of final precise ephemeris,which can't meet the requirement of real-time retrieving atmospheric precipitable water,a method of retrieving atmospheric precipitable water by using ultra-fast ephemeris instead of final precise ephemeris is proposed.Based on the principle of ground-based GNSS inversion of atmospheric precipitable water,using GAMIT software,the atmospheric precipitable water is obtained according to the ephemeris products with different precision provided by the international GNSS service (IGS) website,and compared with the atmospheric precipitable water obtained by meteorological sounding station.The results show that the atmospheric water obtained from the super fast ephemeris can be consistent with the final precise ephemeris.The average difference is smaller than 0.1 mm,and is consistent with the atmospheric precipitable water measured by the sounding station.The accuracy of the two ephemeris can meet the needs of weather forecasting.