PDF document and a MATLAB function named jatmos70.m that implements the algorithm described in the classic report New Static Models of the Thermosphere and Exosphere with Empirical Temperature Profiles, L. G. Jacchia, SAO Special Report No. 313, May 6, 1970, Smithsonian Institution, Astrophysical Observatory, Cambridge, Massachusetts. This implementation also includes the improved integration or quadrature method described in “An Improvement in the Numerical Integration Procedure Used in the NASA Marshall Engineering Thermosphere Model”, by M. P. Hickey, NASA CR 179389, August 1988.
This computer model approximates a dynamic Earth atmospheric where density is a function of the calendar date, universal time, the sub-satellite position, and the solar activity. The model is valid for altitudes between 90 and 2500 kilometers and is useful for modeling the effect of atmospheric drag on the long-term evolution of orbits.