Plate solving - confused about catalogs

[JackG]

Folks,

I not having much luck with plate solving. Googling it appears I need to download the UCAC4 catalog.

The URL in AA8's manual (ftp://cdsarc.u-strasbg.fr/pub/cats/I/322A/UCAC4) gives a baffling list of directories and filenames. What do I download? They are all tarballs and gz's.

Another link from a different site (https://www.cloudynights.com/articles/c ... rt-1-r3225) suggests using this link: https://www.ap-i.net/skychart/en/download. I downloaded those thousands of files to the catalog directory, but get this message when I open the star atlas:

Not Found - UCAC4 C:\Program Files (x86)\Astroart8\Catalog\ucac4-index-v2\ucac4\

However, that directory exists and has the file 4uc.ixr in it, which I presume is the index into the other directories, which I also downloaded into AA8's catalog directory.

Any help sure would be appreciated!

Jack

[Iver]

Hi Jack, AA plate solve data is included with ver. 8
It does not need to be downloaded separately. In the Instrumentation section there is a plate solving with AA8 thread that my be helpful.

[bill]

Hi Jack,

I find that the new catalog (GaiaComp) that is supplied with AA8 works well for plate solving and I personally have not used UCAC4 since this new catalog was released.

Extract the contents of the .ZIP file to its own directory and use the star atlas options to point to this location.
Here is how mine is configured.

If you really want to use UCAC4, then you will need to download the data files with an FTP client like Filezilla and download all the data files and directory structure.
The link you posted is correct and works fine in Filezilla. Transfer type should be set to binary and not ascii.
Total data to download will be about 8.4GB

The link from the Cloudy Nights post is a compiled version of UCAC4 that is only for Cartes Du Ciel Planetarium program and will not work with AA.

Regards,
Bill

[fabdev]

Hi, Astroart plate solving does not use any external star catalog.
UCAC, GAIA, etc. are just for displaying stars in the atlas, changing them will not affect plate solving.
Regards, Fabio.

[Patrick]

Hello,
In the response from Bill above, the display shows the contents of the UCAC4 Directory - 4 sub-directories plus 5 other entries.
For use in Astroart, Which of these needs to be downloaded?
Regards,
Patrick.

[bill]

Hi Patrick,

The main data directory is u4b and is required.

For reference, below is a snippet from the ucac4doc.txt file;

access = example access code (Fortran and C), and sample output
html = snapshot of web pages of UCAC project, history, pictures
papers = some published papers relevant to UCAC, prev.release readme, history
plots = all-sky plots (as described in sections 2 and 3 above)
u4b = binary data files (northern and southern part on 2 sides of DVD)
u4i = index files, supplemental files needed for access code

As Fabio mentioned in a previous post, this catalog is not used for plate solving.

Regards,
Bill

[Patrick]

Bill,
Thank you and understood - only using it for the star atlas.
Regards,
Patrick.