A box-wing-like solar radiation pressure model for GPS satellites and its impact on precise point positioning

This study is mainly to propose a box-wing-like model, termed EBOXW, for handling the solar radiation pressure (SRP) effect on GPS satellite. This EBOXW model assumes the different radiation effects on both the solar panel and satellite bus. We use 20 years (from 2001 to 2020) of GPS orbits as pseudo observations to check the EBOXW performance using the so-called orbit fitting technique. We find that the GPS orbit residuals from the orbit fitting show the periodic variations, which are associated with the SRP model and the GPS Block types. In this work, both the ECOM1 and the ECOM2 SRP models are used to validate the EBOXW model for the effectiveness. Overall, the orbit residuals range from −5 cm to +5 cm for all GPS Block types. In a closer inspection, the ECOM-based model induces more pronounced periodic variation in both the along-track and cross-track directions of IIR-M and IIF satellites than the EBOXW model does. This can be attributed to the periodic terms introduced in the e_D direction of the ECOM-based model. In comparison, the EBOXW model estimates the D0 acceleration only on the satellite X and Z sides, as well as the solar panel. Besides, the three models commonly introduce the significant periodic variation in the radial direction for all block types. Overall, the three models work similarly for the II and IIA satellites. The EBOXW presents the relatively well fitting to the IGS orbit for the IIR-M and IIF satellites, as compared to the ECOM-based model. In the end, we use the precise point positioning (PPP) as an external validation for assessing the impact of the SRP models on positioning. Although the improvement of the PPP solution is insignificant in the EBOXW case, the proposed EBOXW model effectively minimizes the orbital residual bias found in the ECOM-based models for all Block types. This work mainly provides an alternative SRP model for the orbit fitting technique and the related applications.