Improvement in orbit Propagation using Updated Satellite Drag Coefficients and Neutral Atmosphere Specifications

For satellites in Lower Earth Orbit (LEO), atmospheric drag is one of the main causes of error in orbital propagation. The atmospheric drag force can vary significantly as a result of changes in neutral density, temperature, and atmospheric composition. However, available orbit propagation techniques, such as SGP4, use a constant value of drag, which results in significant errors in long-term propagation. The purpose of this study is to improve orbit propagation by performing a more accurate drag analysis. We analyze the interaction between satellite surfaces and neutral particles using diffuse reflection with incomplete accommodation (DRIA) and the Cercignani-Lampis-Lord (CLL) gas surface interaction (GSI) models. Ballistic co-efficients are derived for the GRACE and CNOFS satellites during strong geomagnetic storm periods. Using neutral density and temperature outputs from the NRLMSISE-00 and Global Ionosphere Thermosphere Model (GITM) models along with the drag analysis, we predict and compare the parameters required for orbit propagation, released in the form of Two-Line Elements (TLE) by NORAD.