Parameters for "specred"
Do not forget you need a DS9 before
running this task.
The task parameters for the WFCCD will look like this:
This task will process the spectroscopic images through [BOTZF].
For this purpose it will search for bias, flats, and objects,
using the header keyword "imagetyp". You must use the task 'ccdlist'
before running this task to make sure that the images have the correct
The "prefix" parameter specifies the string in front of all your images.
The "logfile" is the name of a text file where the results of the
processing will be saved. The task will save the plots of the overscan
fits in the "plotfile" parameter, and the raw images will be saved
with a prefix specified by the "backup" parameter.
There are three critical parameter that vary from instrument to instrument,
namely, the CCD "instrument" file, the "ssfile" subset translation file,
and the bad pixel "fixfile" file. In the "snphot" directory you will
find specific files for the instrument that you are using.
Do an implot on one of the flat-field frames, and check that the
overscan and trim sections are right, as well as the image
sections for computing statistics and flat normalization.
Enter the corresponding columns and rows in the "biassec", "trimsec",
and "statsec" parameters.
The "rdnoise" and "gain" parameters are self-explanatory. Make sure
to enter the specific values for your instrument.
Make sure that the image keywords refering to the "grating" and "slit" are
named as in your headers. The header keywords specified with the "grating"
and "slit" parameters, are used by the task to identify spectroscopic
images, and the slit width respectively. The values of "gr_par", "slit_nar",
and "slit_wide" must be set according to the header values.
From your flat determine the useful region for normalization and
enter the resulting section in the "section" parameter. You can
also restrict the sample of points to fit with the "sample" parameter.
The task specred will use this information to
1) process the bias images (you will have a chance to look
at the overscan fits), combine the individual frames, and display
the resulting image "Zero_spec";
2) process the flats separately according to the slit width, combine
and normalize them (you will be required to fit the response function),
and display the resulting images Dflat.nar.norm.fits and
3) process the spectroscopic images found in the working
directory through [BOTZF]. If everything goes well, you should
get a listing of the processed images with [BOTZF] next to
each spectral image name.
The task will output relevant information to the "ccdlog" file,
and keep plots (such as overscan fittings) in the "ccdplot" metacode.
A copy of the raw images will be kept in the same directory, adding a B
in front of the image name (Bccd001.fits, for example).
If something goes wrong during the reduction process, you can
recover your original images from those files.