IF组合PPP及反距离加权法解算ZTD的精度分析

Accuracy Analysis of Ionosphere-free PPP and Inverse Distance Weighted Interpolation Method for ZTD Solution

对流层延迟被公认为GNSS定位中的一项重要误差源,对于定位结果有着不可忽视的影响。本文基于GNSS参数估计过程中通过给定精确的天顶静力学延迟(ZHD),继而对天顶湿延迟(ZWD)进行参数估计这一原理,利用无电离层组合PPP方法解算ZWD继而得到对流层天顶总延迟(ZTD),并和IGS对流层产品比较分析其解算对流层延迟的精度,结果表明,无电离层组合PPP解算ZTD的精度能达到1.4 cm。然后用同样的方法解算测站周边多个参考站的ZTD,利用反距离加权插值法求解测站的ZTD,并和IGS最终对流层产品比较分析其精度,结果表明反距离加权插值法精度可达1 cm。

Troposphere delay is recognized as an important error source in GNSS positioning,it has a significant impact on positioning results.Based on the process of GNSS parameter estimation by a given precise Zenith Hydrostatic Delay(ZHD),and then to estimate the Zenith Wet Delay(ZWD)parameters in this principle,it uses the ionosphere-free PPP method to calculate ZWD and get total Troposphere Zenith Total Delay(ZTD),compares to IGS troposphere products,and then calculates the accuracy of the Troposphere Zenith Total Delay.The results show that the accuracy of the ionosphere-free PPP can reach 1.4 cm.Then,the ZTD of several reference stations around the station are calculated by the same method,and the ZTD of the station are calculated by the inverse distance weighted interpolation method.The accuracy of the inverse distance weighted interpolation method is nearly equal to the final IGS troposphere product and reaches 1 cm.