On 03/17/2013 11:28 AM, Mattia Verga wrote:
I would like to package some additional catalogs for Skychart, but I
have some questions regarding license.
As you can see on skychart download page , each package has more than
one catalog inside. All of these catalogs are known to be public domain,
but there's no license file specified either in catalogs or on original
websites of the catalogs  . Moreover, original catalog data is
reworked by skychart's developer to fit the main program, so the result
only work in skychart.
My question is: can additional catalogs subpackages be the case stated
where it's not necessary to include own license? Or should I contact all
makers of the source data from wich these catalogs are built and ask
them the licenses?
In this specific case of the Navy files, these catalogs are safe to be
treated as being in the Public Domain, and no "license" is necessary to
The Tycho-2 files are less clear. You should ask Erik Høg to clarify the
license on the original source data before packaging them.