An initial investigation of the non-isotropic feature of GNSS tropospheric delay

作     者：Ying Xu Zaozao Yang Hongzhan Zhou Fangzhao Zhang 

作者机构：College of Geodesy and GeomaticsShandong University of Science and Technology579 Qianwangang RoadQingdao266590ShandongChina 

出 版 物：《Satellite Navigation》 (卫星导航（英文）)

年 卷 期：2024年第5卷第1期

页      面：155-167页

核心收录：

学科分类：08[工学] 080401[工学-精密仪器及机械] 081105[工学-导航、制导与控制] 0804[工学-仪器科学与技术] 0825[工学-航空宇航科学与技术] 0811[工学-控制科学与工程] 

基　　金：supported by the National Natural Science Foundation of China(No.42174035) 

主　　题：Tropospheric delay GNSS Non-isotropy Mapping function Ray-tracing Horizontal gradient ERA5 

摘      要：Tropospheric delay is a significant error source in Global Navigation Satellite Systems(GNSS)*** Path Delay(SPD)is commonly derived by multiplying Zenith Tropospheric Delay(ZTD)with a mapping ***,mapping functions,assuming atmospheric isotropy,restrict the accuracy of derived *** improve the accuracy,a horizontal gradient correction is introduced to account for azimuth-dependent SPD variations,treating the atmosphere as *** study uncovers that,amidst atmospheric dynamics and spatiotemporal changes in moisture content,the SPD deviates from that based on traditional isotropy or anisotropy *** innovatively introduces the concept that SPD exhibits non-isotropy with respect to azimuth *** validation involves assessing SPD accuracy using three mapping functions at five International GNSS Service(IGS)stations,referencing the SPD with the ray-tracing *** subsequently evaluates the SPD accuracy with horizontal gradient correction based on Vienna Mapping Function 3(VMF3)***,the non-isotropic of SPD is analyzed through the ray-tracing *** results indicate the smallest residual(1.1–82.7 mm)between the SPDs with VMF3 and those with the ***,introducing horizontal gradient correction yields no significant improvement of SPD *** potential decimeter-level differences in SPD due to non-isotropic tropospheric delay across azimuth angles,a precise grasp and summary of these variations is pivotal for accurate tropospheric delay *** finding provides vital support for future high-precision tropospheric delay modeling.