TOLEOS: Thermosphere Observations from Low-Earth Orbiting Satellites

Abstract

The TOLEOS project will provide new thermosphere density and crosswind observations derived from the accelerometer data of the CHAMP, GRACE, and GRACE-FO missions. The accurate calibration of the accelerometer data and the upgrade of the radiation pressure model are key elements of the project, which is funded by the Swarm Data, Innovation, and Science Cluster (Swarm DISC). To improve the radiation pressure modelling, we use ray tracing techniques in combination with high-fidelity geometry models of the satellites, which were augmented with the thermo-optical properties of the surfaces. This substantially reduces the uncertainty stemming from the satellite geometry modelling and shadowing effects. In addition, we introduce thermal models of the satellites to account for the radiation of heat from the satellites themselves. We will elaborate the accelerometer data calibration and briefly explain the upgraded radiation pressure modelling. Further, we will compare the new thermosphere density and crosswind observations to the existing observations to the highlight the differences and demonstrate the effects of the upgraded processing.