网络RTK对流层延迟内插模型精度分析

Accuracy Analysis of Network RTK Interpolation Models for Rover Station Tropospheric Delay Correction

流动站与参考站间双差对流层延迟的精确改正是网络RTK技术的关键。本文采用河南省地基增强系统参考站网7个参考站的观测数据进行试验,选择LIM、LCM、LSM和KRG模型为研究对象,分析了各模型用于不同高差水平流动站对流层延迟改正的效果。试验结果表明:4种常用内插模型中,LIM和KRG模型对流动站对流层延迟改正的精度较优。流动站与主参考站高差达到400 m时,对于低高度角卫星,模型内插精度降低到分米级,不满足用户流动站高精度定位需求。

The accurate correction of the double-difference tropospheric delay error between the rover station and the reference station is key to the network RTK technology. In this paper, the experiments are based on the observation data from seven reference stations of Henau province ground based augmentation system （ GBAS ）. The linear interpolation method （ LIM ） , the linear combination model （LCM） ,the low order surface fitting model （LSM） and the kriging interpolation method model （KRG） are selected as the research object.Each model are analyzed for the effect of the correction of tropospheric delay error in several rover stations with different elevation difference level.The experimental results indicate that the LIM and the KRG are more accurate in correcting the tropospheric delay among the four conventional interpolation models. When the height difference between the rover station and the main reference station reaches to 400 meters,the interpolation accuracy of the model is reduced to the decimeter level for the low altitude angle satellite, in which the demands of high precision positioning in rover station cannot be met.