BeiDou satellite radiation force models for precise orbit determination and geodetic applications

Abstract

<div>China’s BeiDou satellite navigation system (BDS) has completed its full constellation in orbit since June 2020. Services have been evolved from regional (BDS-2) to global (BDS-3). This contribution evaluates the impact of solar radiation pressure (SRP) modeling on satellite orbits and geodetic parameters. To that end, we process 2 years of BDS observations (2019-2021), collected by a network of 100 ground stations. A physical a priori box-wing (bw) model based on the estimated optical properties is introduced. Various physical effects, such as yaw bias, self-shadowing, radiator emission and thermal radiation of solar panels are considered. The ECOM (Empirical CODE orbit Model, 5 parameters), ECOM+along-track and ECOM2 (both 7 and 9 parameters) models are employed on top of the a priori box-wing model in the experiment. We show that without the use of the a priori box-wing model, the ECOM+along-track model shows clear better orbit solutions during eclipse seasons for BDS-3 satellites. This is proven to be mainly due to the thermal radiation of solar panels. However, the along-track acceleration is highly correlated with LOD (length of day) and ECOM parameters. LOD estimates in this case are contaminated. The STD (standard deviation) of daily LOD estimates with respect to IERS-C04-14 series increases from 40 us (ECOM) to 85 us (ECOM+along-track). After the consideration of the a priori boxwing model, satellite orbital errors are greatly reduced for all the ECOM models. For instance, orbit misclosures of BDS-3 CAST (China Academy of Space Technology) satellites improve by a factor of two for the ECOM model during eclipse seasons; dependencies of SLR (satellite laser ranging) residuals on the sun elongation angle almost vanish for BDS-3 satellites. Furthermore, the use of the a priori box-wing model mitigates a great majority of the spurious signals in the geodetic parameters. In particular, the total amplitude of the 1, 3, 5, 7 cpy signals for the geocenter Z component has been reduced by a factor of 4.5 for the ECOM model. In general, the combination of the introduced physical a priori box-wing model and the ECOM model is preferred for BDS satellites.</div>

Precise orbit determination for BDS satellites

“…However, the satellite body of BDS-3 CAST MEO satellites published by CSNO is a standard cuboid, but it is a bit far from the real. The more precise dimensions are reported by Duan et al (2021b) and listed in Table 2.…”

“…It is worth to mention that the optical properties listed in Table 3 are quite coarse, particularly for BDS-3 SECM MEO satellites. However, with the real tracking data, they can be calibrated as shown by Duan et al (2019Duan et al ( , 2021b.…”

“…11. Comprehensive analysis and modeling of the radiator emission and the thermal radiation of solar panels are presented by Duan et al (2021b) for all BDS-2 and BDS-3 satellites, and the orbit misclosures of BDS-3 satellites are reduced by a factor of two for the ECOM1 model during eclipse seasons.…”

A Parallel Approach for Multi-GNSS Ultra-Rapid Orbit Determination

“…For BDS, no official metadata for a priori box-wing models are available. However, estimated parameters can be still used [33]. Equation (2) is the basic observation equation for ultra-rapid orbit determination.…”