Investigating scale factors of radiation pressure accelerations of SLR satellites

For low Earth orbit satellites, the atmospheric drag is the largest non-gravitational force. With increasing satellite altitude, the acceleration due to the Earth radiation pressure (ERP) decreases, whereas the effect of the Solar radiation pressure (SRP) becomes prevalent. Models of these non-gravitational forces are applied in satellite gravimetry, thermospheric density estimation, and in precise orbit estimation of the spherical satellite laser ranging (SLR) satellites.

In earlier investigations, we found that estimating systematic errors in radiation pressure force models appears possible based on an inverse procedure using GRACE data. Our preliminary results show that the outgoing radiation from CERES SYN data is too small for both longwave and shortwave data.

Here, we want to test the suitability of another approach to obtain estimates for correcting existing radiation data. In this method, we focus on the estimation of scale factors for radiation pressure accelerations of different SLR satellites with the long-term aim to obtain corrections for existing radiation datasets. During the precise orbit determination procedure of the spherical SLR satellites, the scale factors are commonly estimated with a variety of other parameters. Here, we test different parametrizations of the scale factors of both ERP and SRP accelerations and their behaviour for different SLR satellites such as Stella and Ajisai during varying solar conditions. Besides the separate estimation of scale factors for ERP and SRP accelerations, we will estimate global (monthly) scale factors for ERP accelerations from a variety of SLR satellites. Finally, we will investigate the potential of the resulting scale factors to correct existing radiation datasets in the future. At this stage, a comparison to our preliminary estimates from our previous investigations turns out as helpful.