LAMBDA方法在计算GPS信号斜路径水汽含量中的应用

The Application of the LAMBDA Method in the Estimation of the GPS Slant Wet Vapour

随着GPS数据处理技术的提高以及计算精度的提高,GPS在大气科学中的应用日益广泛.在GPS气象学研究中,斜路径水汽含量(SWV)是一个有重要意义的参数.针对宋淑丽等在2004年提出的一种应用精密星历、IGS钟差、和经过周跳处理的LC组合观测值直接计算SWV的方法存在实时性较差的问题,在处理模糊度搜索的问题上应用了目前城市虚拟参考站(VRS)上应用较为成熟的LAMBDA方法.经过数据试算,验证方法可行,计算结果投影到天顶方向有较好的一致性,此方法得到的垂直方向大气延迟(ZTD)与GAMIT,BERNESE的结果比较,与BERNESE结果的符合精度一般小于1.5cm,与GAMIT结果的符合精度一般小于10cm.

By far, the technology of GPS data processing has been improved well and the accuracy of this processing has increased greatly. So, GPS has been applied in meteorology widely. The SWV （Slant Wet Vapour） is a very important parameter in the GPS meteorology. In 2004, Song Shuli had advanced a SWV estimation method which used the precision orbit of JPL, IGS clock and the LC observations without cycle-slip. But this method is bad in real-time character. LAMBDA method, which is working well in the VRS （Virtual Reference Station） /COORS, is used in the ambiguity estimation. The method was proved by some true data calculation. The ZTD（Zenith Time Delay）, which is calculated by pro- jecting SWD （Slant Wet Delay） to zenith direction, has good coherence. Compairing the ZTD with the results of GAMIT and BERNESE, the deviation between our result and the GAMIT one is commonly little than 3cm, and the BERNESE one is commonly little than 1.5cm.