RE: Lots of Data

["Gutzwiller, Michael" <mgutzwiller@lanvision.com>]

There are several reasons to change Star or any other analysis tool set.

* Handle the differences between the stare mode of the Mark IV and the drift
scan mode of the Mark III.  This affects such things as the type of dark and
flat images (full screen vs. vectors), calculation of observation time,
determination of the actual imaging pixels within the image, etc.

* Improve the algorithms used to provide higher quality data.

* Optimization.  I plan to optimize the code in Star to use the 3D-Now
instruction set for some of the analysis to speed things up.  Analysing 2k
by 2k images is SLOW.

* The layout of the images for a Mark IV is different with assumed dark
images, etc.


Thanks,

Mike G.


-----Original Message-----
From: owner-tass@listserv.wwa.com [mailto:owner-tass@listserv.wwa.com]On
Behalf Of Creager, Robert S
Sent: Friday, October 20, 2000 4:24 PM
To: tass@listserv.wwa.com
Cc: 'rob'
Subject: RE: Lots of Data



Why would Star (or any other software) need to change from the Mark III to
the Mark IV images?  From what I understand, the Fits header contains all
the image information necessary to go about analyzing it.  I know I'm
missing something...

I'll start working on a Perl script which will do the brief process Tom laid
out.  I'll work on Linux, but the Perl scripts will be written to work on
Windows also (hopefully).  Since IRAF is public domain with source, I'll
probably spend some time getting it to run on Linux and figuring out how it
works.

1.  For each Fits image in a given location, do the following steps
2.  Parse Fits header to find sky location.
3.  Have IRAF (or other software) identify bright majors in image.
4.  Take stars found in 3 and compare against stellar catalog (presumably to
find exactly where we are in the sky so lower magnitude stars can be
matched?).
5.  Have IRAF (or other software) identify all (or to some magnitude) stars
in image.
6.  Correct magnitude of all stars found (maybe from stars used in 4).
7.  Spit out a list of stars.

That about it for starters?  I know that eventually dark and flat frames
will be needed, along with lots of other stuff, but it's a start...  I'll
try to make the code easy to add new steps/change what software is used.

Later,
Rob

> 
> As I see it, the main job is to write scripts.  Go to this 
> directory, look 
> for .fts files.  When you find one look at the header for 
> where it was 
> looking in the sky.  Match some of the stars in the image to 
> a standard 
> catalog by processing it through IRAF with he proper 
> commands.  Now tell 
> IRAF to find all the stars in the image.  Now correct the measured 
> magnitudes by comparing them to fraction of stars with well 
> established 
> magnitudes, now compute errors and such.