!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....

!General overview of module: DSP_MENU

General overview of module: DSP_MENU (.PRO)

This is what we call the "MAIN MENU" where the user
can select various ways of displaying the observed
CDS data, either from the NIS detector or the GIS
detectors.  The display mode can be selected from a
set of buttons.  The following instructions assume
that the user is familiar with the CDS data
structure and format (see under DATA STRUCTURE or
DATA FORMAT).
	
Only a very brief description of each feature is
given here.  A more detailed discussion can be found
under their separate items in the menu to the left.

!QL_MENU

QL_Menu: 

Used to load a new set of observations (CDS FITS
file) into the current QL session.  A new ``main''
menu will appear, running independently of the
previous.

!Modify Color Table

Modify Color Table:

Modify current color lookup table, change contrast,
or load a new color table.

!Deselected Spectrum

Deselected Spectrum:

Displays a full spectrum or spectral windows from
specific exposures within a raster sequence.  The
individual Spectral Windows are DESELECTED into
their corresponding positions on the detector.  Line
selection and windows given in Blue Book can be
displayed.  Measurement of wavelengths and positions
on the detector is possible together with line
identification.

  IDL> dspspec, a           ; If called from IDL prompt


!Wavelength Slice/Profile

Wavelength Slice/Profile:

Display data slices at specific wavelength together
with line profiles.  A window is created with two
types of display of the data in four selected
spectral windows.  The upper display is a cross
section of the data at a specific wavelength, giving
a spatial view of the region that has been scanned
by the CDS NIS/GIS.  The lower display is the
intensity profile along the dispersion direction
(line profile), at a selected point in the
two-dimensional image displayed in the window above.

  IDL> dspwav, a            ; If called from IDL prompt

!Spectral Window Exposure

Spectral Window Exposure:

Display all exposures of selected Spectral Windows.
A window is created to show all the exposures of the
selected Spectral Windows, spread out one after
another, and to report the identity of the Spectral
Window/exposure number that is clicked on by the
user.

  IDL> dspexp, a            ; If called from IDL prompt

!NIS Movie

NIS Movie:

Shows a full raster sequence of a selected line
window as a continuous movie.



!General Help

General Help:

By selecting ("pushing") this button a widget appear
with a list of the various options (buttons)
available in the active main menu.  By selecting one
of the options, information about this feature will
be displayed in the text window to the right.  In
addition to help about specific features a general
overview of the Quicklook software is also
available.



!Structure Browser

Structure Browser:

Display contents of a structure as a pulldown menu.
A pulldown menu is created representing all the
levels of "introspection" of the structure variable.

!FITS Header

FITS Header:

Displays basic information in a window about the
structure containing data from a CDS FITS level-1 file.
Optional display of information concerning each spectral
window appears in a separate window, as is also the case
with the optional display of auxiliary data information.

  IDL> dsp_info, a          ; If called from IDL prompt 
  IDL> dsp_info, a, /aux    ; For the auxiliary information
  IDL> dsp_info, a, /info   ; For the window information


