Copyright UKSSDC at RAL.
This is an empirical model of the temperature and composition of the atmosphere at heights between 85 and 700km. It is based on mass spectrometer data from various satellites and on incoherent scatter radar data from several sites. Full details are given in the paper by A E Hedin which was published in the Journal of Geophysical Research, Vol 92, pages 4649-4662 (May 1987).
The program implemented here allows you to supply a range and step size for either latitude, longitude, height or time for the geomagnetic conditions prevalent for a particular date. The necessary values of Ap and solar radio flux are retrieved from the WDC C1 databases for a particular day. The values for the non-varying parameters are taken from the minimum for each of the other parameters.
The program produces for each time, altitude, latitude, longitude a table giving temperature, densities for N2, O, He, A, O2, H, N, and total mass density.
The Fortran code is based on a program developed by Hedin. It has been modified by the WDC to use the database and to provide a 'user-friendly' interface. If you have any suggestions for changes please let us know.