Validation of Thermospheric Density Models for Drag Specification

Tuesday, 16 December 2014
Nathan J Boll, University of Michigan Ann Arbor, Ann Arbor, MI, United States, Aaron J Ridley, Univ Michigan, Ann Arbor, MI, United States and Eelco Doornbos, Delft University of Technology, Aerospace Engineering, Delft, Netherlands
The rate of deployment for small satellite constellations into low earth orbit (LEO) is rapidly increasing. At these altitudes, the orbital characteristics of low mass spacecraft are heavily impacted by atmospheric drag. Given that many such satellites do not possess systems capable of applying thrust to correct for these perturbations, the ability to perform station-keeping maneuvers, as well as to adjust and maintain the relative position of each spacecraft within a constellation, is greatly dependent on the ability to accurately model variations in the thermosphere-ionosphere density. This paper uses density data measured along the orbital paths of the Challenging Minisatellite Payload (CHAMP), the Gravity Recovery and Climate Experiment (GRACE), and the Gravity field and steady-state Ocean Circulation Explorer (GOCE) to validate and compare several atmospheric models, including the Global Ionosphere Thermosphere Model (GITM), the US Naval Research Laboratory Mass Spectrometer and Incoherent Scatter Radar (NRLMSISE-00), and the Jacchia-Bowman 2008 empirical thermospheric density model (JB2008), under various geomagnetic activity levels and seasonal conditions.