[Kstars-devel] KStars and custom catalog loading

[Mike McGavin]

Hello.

I was wondering if I could ask what the state is of KStars' handling
of custom catalogues, and are there any particular recommendations for
getting custom catalogs to load efficiently?

I've been experimenting with trying to load the Tycho-2 catalogue in
kstars 3.5.2 (the most recent build in Debian).  I like star hopping
to faint objects with my telescope, and I'm quite keen to get stars
down to about 12th or 13th magnitude, when zoomed in to a small enough
area, at least.

I've had a few problems, though, mostly with kstars apparently not
being able to handle the size of the input data.  The entire Tycho-2
comes as about 500 MB uncompressed, even though most of the fields can
be filtered out during import.  I gave up on the Import Catalog
feature, because I couldn't get it to recognise the data format.  Even
so, it didn't seem as if it wasn't quite designed to cope with
massively sized cataloges, and I managed to crash it several times
without too much trouble.

I then wrote a short Python script to manually convert about 1/75th of
the Tycho2 catalogue (~35000 stars) to the kstars custom catalog
format.  Kstars is able to load this, but the startup time slows to a
crawl at the 'loading custom catalogs' phase.  Just now it's taken 11
minutes to load compared with a matter of seconds.

I'm guessing this slow-down is because custom catalogs aren't indexed
in the same way as kstars' internal catalogs, although you guys would
know better than I would.  Also, once kstars actually does finish
loading, I haven't been able to confirm that the additional stars are
even being displayed.  I've searched the areas of sky concerned, and
can only find relatively bright stars that I think are probably still
from Hipparcos.

Is there any alternative way to load data, and maybe index it, that
might help kstars access it more directly and efficiently?  If there's
a consistent format and/or index format somewhere, I might just be
able to write another script to convert the catalogs I'd like so that
kstars can use them effectively.  If extra catalogs simply aren't well
supported at this time, that's okay.  I'm just keen to know if there
are any possible workaround that I might try.


Thanks.
Mike.