Thanks, Bill. I believe I'm following along.

So if I only decompressed, say z180 through z360, I should be fine for north of the celestial equator, right?

I did this (for example, the uncompressed z180 is 25,626,384 bytes) and still I don't see UC3 designations for stars in these files.

Is there anything I can send you config-wise that may shed some light on this? Please?

Grant

--- In guide-user@yahoogroups.com, Bill J Gray <pluto@...> wrote:
>
> > I take part of that back. I think I'm using USNO A2.0 for PinPoint, not UCAC3.
>
> Most likely, yes. I just checked; it would be theoretically possible, I
> think, to read a .bz2 file in a suitably "random" way that would let PinPoint
> (or Guide) access some data from the middle of the compressed file. That would,
> in fact, be very handy in some situations. But I doubt it's what PinPoint
> is doing.
>
> > So decompressing all the .bz2 files should be sufficient, right? All 360 of them...
>
> Yes. If you don't really need the far southern files that cover areas
> you can't see from your latitude, you can neglect (say) z001 to z080, thereby
> leaving out declinations -50 to the south celestial pole. It probably won't
> save you a lot, though.
>
> -- Bill
>