LIRIS
Long-slit Intermediate Resolution Infrared Spectrograph for the WHT
DATA REDUCTION
Quick Look Analysis

This software is intended to be used in order to perform a quick analysis of the LIRIS data while observing at the telescope, but is not intented to provide fully reduced data. It is developed as an IRAF package, easy to install at any place.
 

      This package, its documentation and the information given here have been created by Jose Acosta at IAC. This package is largely based on the similar package, ingrid_ql, developed by Robert Greimel at ING.

                                    Using the LIRIS quick look package
 

      To use the LIRIS quick look package:

            Open an ximtool (or another display tool) to display the data (i.e. type ximtool& or ds9&, for example).

            Start an IRAF session: open an xgterm, change to the home directory and type cl (or ncl). The prompt will change
            to cl>

            Type: cl> liris_ql. The prompt will change to li>

            Type: li>help usage, to get information about the use of the package

            Type: li>help to get a list of the available tasks.

            Type: li>help task_name to get more information on using each particular task.

      Some of the most frequently used tasks are:

                   idedither - combine dithered images
                   idispframe - display frame (post-pre)
                   istarfocus - find focus from focusrun images
                   icombine - combine images
                   ifindron - find readout noise from two dark frames
                   iframediff -  calculate and store post-pre
                   ilistdark - list dark exposure times needed
                   istatistics - calculate image statistics
                   isubtract - subtract two images

                                                                  Useful examples

When you take an exposure with LIRIS the array is reset and immediately read out. This is called the pre-read image, and
      is stored in extention 1 of the file (rNNNNNN.fit[*,*,1]). After the exposure time has passed the array is read out again. This is
      called the post-read image and is stored to the extention 2 of file (rNNNNNN.fit[*,*,2]). The information useful for the observer is
      the difference between these two images. The liris_ql package provides a quick way to access this information.
 
 

Pipeline Processing

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Last modified: 08/03/02
Page mantained by: Jose Acosta and Mary Barreto