e="font-family: ms sans serif;"> <br>
There are several &#8220;MSIS&#8221; models, namely the MSIS-86, MSISE-90 and
NRLMSIS-00. They can be easily found and downloaded at <a href="http://ccmc.gsfc.nasa.gov/modelweb/">Goddard NASA&#8217;s
Model Web</a>
. Above 120 km they are
essentially the same, since major differences occur at low altitudes.
They were coded, naturally, in FORTRAN. Some C/C++ versions can be
found on net, but it seems that there is no C version for 86&#8217;s model,
except by those