Comparison and Accuracy Assessment of Semi-Empirical Atmosphere Models through the Orbital Decay of Spherical Satellites

A detailed comparison and assessment of the accuracy of semi-empirical atmospheric density models (JR-71, MSIS-86/90, TD-88) were carried out by analyzing the orbital decay of nine spherical satellites in the 150–1500 km altitude range. The orbital decay data used were distributed over a full solar activity cycle (1987–1999). The drag coefficients which were estimated by fitting the observed semimajor axis evolution with a high accuracy orbit propagator were compared with those computed by theoretical analysis.