An assessment of new satellite total density data for improving upper atmosphere models

The DTM series of atmospheric density models (Barlier et al., 1977; Berger et al., 1998) have been developed for atmospheric constituent representation and precise orbit computation. They are based upon satellite drag total density data which are implicitly averaged over one or more days. proach consists of refining the computation of the density model coefficients with more precise orbit computation, using the information contained in the tracking data. Satellite Laser Ranging (SLR) in case of Starlette (800 km) and GFZ-1 (380 km), Doppler-DORIS in case of SPOT2 (800 km). as been verified by comparison of the new density values to Dynamic Explorer 2 (DE-2) measurements, as well as by precise orbit computation. In both cases, an improvement of a few percent has been achieved, showing the interest of the method. tudy has been done in preparation for the new accelerometric mission CHAMP for which we prepare a new gravity field (GRIM5) using the orbit perturbation technique, as well as an improved density model, hence improving the drag modeling.