[freeciv-data] Copyright again

[Gerhard Killesreiter <killesreiter@xxxxxxxxxxxxxxxxxxxxxx>]

Hi!

In my first attempt to draw a river delta as a tile for freeciv, I
have used a photo from NASA. Does anybody know about the copyright
status of their pictures? I did not find anything on their site:
<http://daac.gsfc.nasa.gov/DAAC_DOCS/geomorphology/GEO_5/GEO_CHAPTER_5_TABLE.HTML>

Should I bother them with questions about GPLing their pics? It is
quite impossible to recognise the pics afterwards. I can mail my
attempt to anybody interested later this day. It it however not a
single tile, but an ensemble of 6 tiles.

Usage would be (Land, Ocean, Delta, River):

OOOOL
ODDDL
LDDDL
LLRLL

Cheers,
        Gerhard