The Comparison of Dry Hydrostatic Delay Measurement from GPS Ground-Based and Space- Based Receiver

Abstract

—Tropospheric delay is a significant cause of the Global Navigation Satellite System’s (GNSS) services degrading, particularly when it comes to the geodetic estimation of coordinates on the surface of the planet. To quantify the delay brought on by the abnormalities in the tropospheric layer, researchers have employed a variety of methods. Since Global Positioning System Radio Occultation (GPS-RO) systems and the Global Positioning System (GPS) ground network estimate the tropospheric delay differently, we examined this measurement difference in this study. Therefore, this study has been performed to analyze the dry delay measurement from the ground-based station and validate it with the reprocessing data from the space-based station to understand the correlation of measurement between these two methods. The MetopA gave the worldwide delay data, while the 92 SuomiNet Network GPS stations, which cover the majority of the United States region, provided their measurement of the delay utilizing the element of slant water along the GPS ray while the MetopA provided the global data with around 150 selected data per day and analysis was conducted for the data in the year 2020. Hence, due to the difference in spatial data distribution between these two types of data, the mean value has been measured for each of the latitude zones, the result shows the minimum bias of 0.67 cm and RMSE 4.51 cm at the − 30⁰ to − 60⁰ and the maximum bias of 3.74 cm and RMSE 25.1 cm at the 30⁰ to 60⁰ latitude. Overall bias and Root Mean Square Error ( RMSE) are 1.41 cm and 23.2 cm respectively which shows a good agreement between space-based and ground-based measurement that will help for better error modeling development in the future.