Tropospheric delay estimation and influencing factors analysis of GNSS multi-system

Abstract

Abstract In this paper, the tropospheric delay parameters are estimated by GNSS regional network solution, and the different factors affecting the estimation of tropospheric delay parameters are analyzed experimentally. The high-precision tropospheric delay correction file (.ztd) provided by IGS and the traditional model estimation of the GNSS regional network are compared to verify the final positioning accuracy. The main factors affecting the estimation of tropospheric delay parameters and the conditions conducive to the estimation of tropospheric delay parameters in the data solution process are obtained. The experimental results show that: (1) GPS has the highest tropospheric delay estimation accuracy in the European region, Galileo is slightly worse than GPS, and BDS has the lowest tropospheric delay estimation accuracy; (2) The tropospheric delay estimation accuracy of post-product in different satellite precision products is better than that of real-time products, and CLKM2 is better than CLK93 in real-time products. With the increase of satellite systems, the accuracy of tropospheric delay estimation is gradually improved. Compared with the GPS single system, the accuracy of the GPS+ Galileo+BDS triple system is improved by about 7.2%, 7.2%, and 7.5%; (3) The tropospheric delay estimation accuracy of the European region is better than that of the Australian region; (4) Based on the BDS whole system data solution, the high-precision tropospheric delay correction file (.ztd ) has better positioning accuracy, and the tropospheric delay estimated by the GNSS observation data through the traditional Saastamoninen model of the regional network can also meet the current high-precision positioning requirements in terms of positioning accuracy. The horizontal direction is better than 2 cm, and the elevation direction is better than 4 cm.