Space Physics Data Facility
NASA/Goddard Space Flight Center
This software may be copied or redistributed as long as it is not sold
for profit, but it can be incorporated into any other substantive
product with or without modifications for profit or non-profit.
If the software is modified, it must include the following notices:
The software is not the original (for protection of the original
author's reputations from any problems introduced by others)
Change history (e.g. date, functionality, etc.)
This copyright notice must be reproduced on each copy made. This software
is provided as is without any express or implied warranties whatsoever.