Comparison Of Atmospheric Density Models in the Thermospheric Region: MSIS-86 and DTM-78

The German Satellite CHAMP (Challenging Minisatellite Payload) has the unique ability to measure the surface forces present. The total density can be easily derived from this measurement, with the help of models of solar radiation pressure and Earth’s albedo. This total density will be compared with the total density from two models, MSIS-86 (Hedin, 1987) and DTM-78 (Barlier et al., 1977). The total density from the CHAMP satellite is derived assuming instrument biases can be accurately estimated and that upper atmospheric winds are negligible. Therefore, the noise on the instrument grows as a function of latitude and geomagnetic activity, both indicators of upper atmospheric winds. In conclusion, in order to better determine orbits in the future (without having an accelerometer onboard), an accurate wind model is needed for the Thermosphere.