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Re: Processing Data

On Sun, 30 Apr 2000 11:18:07 -0700, Chris Albertson <chrisja@jps.net> wrote:
*>I'll go out on a limb and make a prediction about Mk IV data reduction:
*>  I think there will be two camps: Star and IRAF,
*>Anyone planning using on some other system?

I don't know about Mark IV, but I *do* know about Mark III data reduction:
I wrote a Tech Note about it. The short story is that there were other
reduction systems in use for those cameras. Exerpts are below: if there are
any errors of fact let me know. I've added comments in []'s to provide some
context. Read my Tech Note for all the details. I presume the future will
have something to do with the past, so this info is relevant to your
question. This is one reason I wrote that Tech Note, for *reference*.

*>Both Star and IRAF work now.  Maybe some scripts need to be put together
*>to string along the various functions but the data reduction pipeline
*>is basically already available.
*>Well almost.  The above just produces star lists.  One list per frame.
*>In the past we have sent these in to Michael who combines them
*>in a database.  I don't think this will work for the Mark IVs.  There
*>will be just to much volume.  I think we will want to merge the lists
*>at the camera sites.  "Merge" as I use the term really just means
*>putting a catalog number of each star.  We [n]eed to write this.

If you read M. Richmond's Tech Note on TenXCat, he does more than
"combine" them into a database. He corrects them photometrically
so they are normalized to each other and (I believe) to other references.
Other Mark III camera members (Glenn for instance)
have their own databases for their own observations, and presumably
make their own corrections or not. My Tech NOte references camera
owner's Web sites, they will have the details. Any corrections to my
Tech Note would be appreciated and I'll update accordingly.

Herb JOhnson


TN 0057: Mark III databases; software and datasets by site
author: Herb Johnson, with quotes as noted by TASS members
Date: Sept 20 1999

At this time (July 1999) there are three Mark III contributors to the
current TASS database of Mark III data from which Michael Richmond compiled
his catalog "TenXCat" in June 1999:

* #Glenn Gombert, Dayton OH">Glenn Gombert triplet in Dayton, Ohio
* #Mike Gutzwiller, Cincinnati OH">Michael Gutzwiller triplet
in Cincinnati, Ohio  (latitude 39.2001, longitude 84.5828)
* #Tom Droege, Batavia, IL">Tom Droege triplet in Batavia, Illinois

[These three contributors used "star" and related programs to reduce their
data. Here's a note on star for convenience:]

Star ; takes a raw image, subtracts a dark vector, divides
by a flat vector, and creates the corrected image. The corrected image
may then be saved in FITS format. Star will also produce star lists from
the corrected image. The new version of star also requires either the SAO
catalog subset (147 Kb, Mar 16, 1997), the Guide Star Catalog subset (840
Kb, Mar 17, 1997) or the recommended Tycho catalog subset (1139 Kb, Sep
7, 1997) to solve for exact RA and Declination.

Output from star is suitable for entry into the TASS database, but
often processing by the following programs is performed prior to database
entry. These constitute the "post-processing" of Mark III data as of 1999.

[Glenn uses star to process Mark III data, but other programs
Glenn Gombert has or is working with includes:]

Sextractor - (??) Processes FITS image w/ WCS parameters and 
"zero point magnitude" (?)
Also uses in some fashion list of reference stars in image, and produces
into star list of X, Y, instrumental magnitude.
See #TASS Tech Notes">Tech Note 27, Automated TASS
Photometric Reduction/Calibration, for Glenn's operation of the Sextractor program.

[Here's notes on Mike Gutzwiller's processing.]

"Mike Gutzwiller, Cincinnati OH">Mike Gutzwiller, Cincinnati OH site

Collecting and processing software:
(acquisition program not clear: tm3get or RT Linux driver?)
flat: (win 95)
star: (win 95)
starpost: (win 95)
flatcomp: (win 95)

Mike has built a Oracle database of his own observations, and has used
a number of programs to produce variable candidates since mid-1999. In
Aug 1999 he announced that he would migrate some of his software tools
to support the TenXcat and TASS database; check his Web site for details.

"Michael Richmond, Rochester NY">Michael Richmond, Rochester NY site
His Mark III camera was formerly in VT, now it is in Rochester NY.
No observations from this triplet have been entered into the TASS database,
as of Aug 1999.

MarkIII Linux driver: (Molhant/Albertson) acquisition
XVista: (Richmond/Treffers) Unix package for reducing images to star
lists. See #TASS Tech Notes">Tech Note 32, Comparison of
several methods of extracting magnitudes, for Michael's discussion
of the use of XVista on TASS images for photometric analysis.

Herbert R. Johnson              http://pluto.njcc.com/~hjohnson
hjohnson@pluto.njcc.com         voice 609-771-1503, New Jersey USA
             amateur astronomer and astro-tour guide
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