Abstract:In order to study the uncertainty of single point positioning deviation caused by the spatiotemporal difference of tropospheric delays, firstly, we use the IGS ZPD product to analyze the correlation between the maximum, minimum, mean, STD and spatial distribution of the station. The results show that the ZPD average is around 2.4 m. There is an overall tendency to decrease with increasing latitude. However, it is not completely symmetrical along with the equator, and the dispersion is slightly larger in the northern hemisphere. Then, based on single point positioning model, the influence formula of tropospheric delay on the calculation of positioning parameters is derived, and its influence on single point positioning is evaluated. The results show that the positioning deviations caused by tropospheric delay are the largest in the U direction, reaching 7 to 15 m; the most insignificant deviations are shown in the E direction, within ±0.2 m; and the deviations in the N direction are centered within ±0.6 m.