CCDSAT

Name

ccdsat

Purpose (one Line Only)

Find saturation properties of a CCD from one or more images

Description

This program will scan one or more CCD images and will save the highest
count seen at each row. This will not be particularly interesting for
just one image but when fed data from one or more nights a curve will
emerge that shows the saturation level of the device as a function of
row number.

Calling Sequence

ccdsat,fn

Inputs

fn - one or more file names to scan, default='' which means to use PATH and
PATTERN to get the files

Optional Input Parameters

Keyword Input Parameters

OUTFILE - Name of output file, default = 'ccdsat.dat'
PATH - Path of where to find the source images, default=current directory.
PATTERN - File searching pattern, default='*.fits'
PEAKS - Array containing previous peak values vs. row number for each
amplifier. Default is to start with a fresh array filled with
zeros.
FITS - Flag, if set will indicate that the output file should be written
in FITS format. The default is to write an ASCII file which
contains the numbers in tabular format, one amplifier to a column.
NOPLOT-Flag, if set, the plots will not be generated.

Outputs

A file, name given in OUTFILE, is written with the peak value seen on each
row for each amplifier.

Keyword Output Parameters

PEAKS - Array containing peak values vs. row number for each amplifier

Common Blocks

None.

Side Effects

Plot window 0 is used to show the results of the peak finding process
as each image is scanned. The green curve is the overall peak and the
red curve is the peak of each individual image.

Restrictions

The images given to this program should all be the same size and must match
the size of the PEAKS input array (if provided). Also, this program won't
help if the data don't contain truly saturated pixels somewhere in the
images.
Any frame whose dimensions do not match the first frame processed will
be skipped with a diagnostic message.
This program is still new and is not fully general yet. It only works
on multi-group FITS images at this point and the plot window is hardcoded
to a 4x4 grid of plots that make the most sense for the 16-amp readout
data from the CTIO Mosaic camera.

Procedure

The simplest usage of this program is to give it one night's worth of data.
Ex:
ccdsat,path='/mydata/night1'
this will look in /mydata/night1 for any file that ends in .fits You
will see a plot with each image and the saturation level will begin to
emerge as each successive image is readout. If you need to customize the
file list, you can do so by providing your own array of file names and
bypassing the automatic scanning.
If you wish to see an aggregate saturation curve that covers multiple
nights, use the PEAKS keyword and collect the answer into a variable
that will be reused for later nights, ie.:
ccdsat,path='/mydata/night1',peaks=peaks
ccdsat,path='/mydata/night2',peaks=peaks
ccdsat,path='/mydata/night3',peaks=peaks and so on.
Each run of the program will start where the previous run left off and the
final run will contain the cumulative answer for all nights.

Modification History

Written by Marc W. Buie, Lowell Observatory, 2003/08/30
2003/09/10, MWB, added PEAKS keyword, additional cleanup of code
2003/11/13, MWB, added code for simple images (no extensions)
2004/9/21, MWB, removed obsolete call to Findfile
2007/12/04, Peter L. Collins, Lowell Observatory, added /NOPLOT and
test to skip odd sized (sub) frames.