COPYING.NRLMSISE-00

    I am placing my NRLMSISE-00 C code into the public domain
    contingent on the original Fortran code not being subject
    to US copyright.

The original Fortran code states the following:

    %The source code is in the public domain and not licensed or under
    %copyright. The information and software may be used freely by the public.
    %As required by 17 U.S.C. 403, third parties producing copyrighted works
    %consisting predominantly of the material produced by U.S. government
    %agencies must provide notice with such work(s) identifying the U.S.
    %Government material incorporated and stating that such material is not
    %subject to copyright protection.
    %
    %Derived works shall not identify themselves in a manner that implies an
    %endorsement by or an affiliation with the Naval Research Laboratory.
    %
    %RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF THE
    %SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY THE NAVAL
    %RESEARCH LABORATORY FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE ACTIONS
    %OF RECIPIENT IN THE USE OF THE SOFTWARE.