The fors_subtract_sky_lss recipe
===============================================================

.. data:: fors_subtract_sky_lss

Synopsis
--------

Subtract sky from calibrated long slit exposure

Description
-----------

This recipe is used to subtract the sky from wavelength calibrated
scientific spectra produced by the recipe fors_resample. A simple median
signal level is subtracted from each image column.

In the table below the MXU acronym can be read alternatively as MOS
and LSS, depending on the instrument mode of the input data. The acronym
SCI may be read STD in case of standard stars observations.

Note that only LSS or LSS-like MOS/MXU data are to be processed by this
recipe.


Input files
^^^^^^^^^^^^
::

  DO category:               Type:       Explanation:         Required:
  MAPPED_ALL_SCI_MXU         Raw         Scientific exposure     Y

Output files
^^^^^^^^^^^^
::

  DO category:               Data type:  Explanation:
  MAPPED_SCI_MXU             FITS image  Rectified scientific spectra
  MAPPED_SKY_SCI_MXU         FITS image  Rectified sky spectra


Constructor
-----------

.. method:: cpl.Recipe("fors_subtract_sky_lss")
   :noindex:

   Create an object for the recipe fors_subtract_sky_lss.

::

   import cpl
   fors_subtract_sky_lss = cpl.Recipe("fors_subtract_sky_lss")



.. seealso:: `cpl.Recipe <https://packages.python.org/python-cpl/recipe.html>`_
   for more information about the recipe object.

Bug reports
-----------

Please report any problems to `Carlo Izzo <usd-help@eso.org>`_. Alternatively, you may 
send a report to the `ESO User Support Department <usd-help@eso.org>`_.

Copyright
---------

This file is currently part of the FORS Instrument Pipeline
Copyright (C) 2002-2010 European Southern Observatory

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA


.. codeauthor:: Carlo Izzo <usd-help@eso.org>
