!CDS Quicklook Software

How to get started

After entering IDL we need to read a CDS FITS file
containing science data. This can either be done by
calling the routine READCDSFITS and specifying a
certain file or by using a menu that will display
the data files available.  We start with the last
approach since you then do not need to know were
files are located. The routine to use is called
QL_MENU and is invoked by

  IDL> ql_menu

A widget menu will appear where you can select a
file to be read into IDL.  This routine will call
READCDSFITS, which retrieves the data in the CDS
FITS file (see below). The Main QL menu will
thereafter appear. Thus, you are now running the
software in Menu-mode.

The method of interactively reading an observation
sequence into IDL is to use the function
READCDSFITS.  (To read the data obtained during the
instrument calibration testing use the function
READCALFITS.)

  IDL> a = readcdsfits('testdata2.fits')
  IDL> a = readcdsfits(concat_dir('$CDS_NIS','testdata2.fits'))

The latter specifies the directory using the routine
CONCAT_DIR.  READCDSFITS returns the entire contents
of the file in an anonymous IDL structure variable
called a QuickLook Data Structure (QLDS).
A set of data cubes, one for each line window in the FITS file,
resides within the QLDS and can easily be passed
between different routines.


!CDS data structure

The CDS data structure:

To be written....



!DESELECTED SPECTRUM MODE

DESELECTED SPECTRUM MODE

The full spectrum or spectral windows from specific
exposures within a raster sequence are displayed.
The individual Spectral Windows are DESELECTED into
their corresponding positions on the detector.
Various features are available and will be discussed
below.  First of all we describe the different
actions of the cursor and mouse buttons.


!Cursor Action

Cursor Action

Use this button to select the wanted cursor
action. Default is to measure positions in the
displayed spectrum. The current mouse button action
is displayed in the upper right corner of the
window. The options are:

 1) Measuring positions:  
	
	Move cursor and click on the left mouse button. The
	current cursor position and the corresponding
	wavelength, intensity, pixel address etc. are
	displayed in the status line.  The middle mouse
	button has been dedicated to send measured
	quantities to a log-file (widget window) that is
	editable so the user can type comments during a
	session.

 2) Line Identification:


	Line identification is possible using the extensive
	line list published by Kelly (1987). By pointing at
	selected lines the information from Kelly, such as
	laboratory wavelengths, element, energy levels, and
	configuration are displayed.  The ``unreadable''
	atomic configuration listed in the electronic
	version of Kelly is decoded into the standard format
	used in the printed version.  The routine pick_line
	can be used to access the Kelly line list in command
	mode.

 3) Zooming:

	Creates a zoomed image of a user-defined region of
	the displayed spectrum. A region of interest is
	selected with the left mouse button.  New areas can
	be selected by moving the cursor and clicking the
	button again. Zoom in and out by moving the cursor
	inside the zoom window.  More details can be found
	under the description of the zoom routine PQLZOOM.
 
 4) Extract profiles:

	Extracts profiles of a user-defined region of the
	displayed spectrum. A region of interest is selected
	with the left mouse button.  New areas can be
	selected by moving the cursor and clicking the
	button again. Profiles both along the direction of
	dispersion and along the slit can be extracted. The
	width and the height of the selected area are
	controlled by widget sliders. The output can be
	saved to a postscript file or printed directly to a
	printer.

!   1) Measuring positions
 
Measuring positions
	
Move cursor and click on the left mouse button. The
current cursor position and the corresponding
wavelength, intensity, pixel address etc. are
displayed in the status line.  The middle mouse
button has been dedicated to send measured
quantities to a log-file (widget window) that is
editable so the user can type comments during a
session.

!   2) Line Identification

Line Identification

Line identification is possible using the extensive
line list published by Kelly (1987). By pointing at
selected lines the information from Kelly, such as
laboratory wavelengths, element, energy levels, and
configuration are displayed.  The ``unreadable''
atomic configuration listed in the electronic
version of Kelly is decoded into the standard format
used in the printed version.  The routine pick_line
can be used to access the Kelly line list in command
mode.

!   3) Zooming

Zooming

Creates a zoomed image of a user-defined region of
the displayed spectrum. A region of interest is
selected with the left mouse button.  New areas can
be selected by moving the cursor and clicking the
button again. Zoom in and out by moving the cursor
inside the zoom window.  More details can be found
under the description of the zoom routine PQLZOOM.
 
!   4) Extract profiles

Extract profiles

Extracts profiles of a user-defined region of the
displayed spectrum. A region of interest is selected
with the left mouse button.  New areas can be
selected by moving the cursor and clicking the
button again. Profiles both along the direction of
dispersion and along the slit can be extracted. The
width and the height of the selected area are
controlled by widget sliders. The output can be
saved to a postscript file or printed directly to a
printer.



!Done

Done: 

When the DONE button is pressed the DSPSPEC window
is exitted and all related widget interfaces are
destroyed.

!Modift Color Table

Modift Color Table:

Modify current color lookup table, change contrast,
or load a new color table. Calls the standard IDL
routine XLOADCT.

!Mark Lines

Mark Lines:

On screen plot of line lists defined in the CDS Blue
book.  User defined line lists may be supplied in
the directory $CDS_INFO.

!Dummy Spectra

Dummy Spectra:

Displays a NIS dummy spectrum covering the entire
wavelength range.

!Hard Copy

Hard Copy:

Create a postscript plot of the entire spectrum
(screen) to be printed or saved to file.

!Help

Help:

Activating the QL Help widget where information
about how to use the different features in the
DSPSPEC window are shown.  By selecting one of the
options, information about this feature will be
displayed in the text window to the right.

!Select Exposure Slider

Select Exposure Slider

Use the slide to select an exposure within the
raster.

