Updated thermospheric neutral density retrieval from geodetic satellite's accelerometer data with improved drag model based on DRIA and detailed finite element satellite models

The neutral mass density of the upper thermosphere can be determined by orbit and accelerometer data from Low Earth Orbit (LEO) satellites. Especially the accelerometers of geodetic satellites, measuring the non-gravitational accelerations acting on these satellites, are a very useful observation for precise density estimation also on very short time scales. Currently, due to the lac of direct measurements, the most accurate atmospheric density estimates are computed from such data.

We present here our latest density solution based on a new approach for the drag coefficient (Cd) modelling. We employ the DRIA (Diffuse Reflection with Incomplete Accommodation) drag model but changed the utilization of the model with our detailed Finite Element Models (FEM) processing and the shadowing computation within the approach. We compare resulting density and Cd values with our previous published data (zarm.uni-bremen.de/zarm_daten/), as well as with data from TU Delft and show the effect of the different Cd modelling approaches on the estimated density. Exemplarily we use here the data from GRACE and GRACE-FO.