NAME

       fors_img_screen_flat - Compute master screen flat frame

SYNOPSIS

       esorex fors_img_screen_flat [OPTIONS] FILE.sof

DESCRIPTION

       After  bias  subtraction,  the  input  flat  field  frames are combined using the given stack method. The
       combined frame is finally normalised dividing it by its large scale illumination trend. The  large  scale
       trend  is obtained by applying a median filter with a large kernel. To avoid boundary effects, the median
       filter is applied only to the specified region.

       The overscan regions, if present, are removed from the result.

       Input files:

         DO category:               Type:       Explanation:         Required:
         SCREEN_FLAT_IMG            Raw         Screen flat field    Y
         MASTER_BIAS                Raw         Master bias          Y

       Output files:

         DO category:               Data type:  Explanation:
         MASTER_SCREEN_FLAT_IMG     FITS image  Master screen flat field

OPTIONS

       --stack_method <str>
              Frames combination method (str; default: ´average´). The full name of this option for  the  EsoRex
              configuration file is fors.fors_img_screen_flat.stack_method [default = average].

       --minrejection <long>
              Number  of  lowest  values to be rejected (long; default: 1). The full name of this option for the
              EsoRex configuration file is fors.fors_img_screen_flat.minrejection [default = 1].

       --maxrejection <long>
              Number of highest values to be rejected (long; default: 1). The full name of this option  for  the
              EsoRex configuration file is fors.fors_img_screen_flat.maxrejection [default = 1].

       --klow <float>
              Low  threshold in ksigma method (float; default: 3.0). The full name of this option for the EsoRex
              configuration file is fors.fors_img_screen_flat.klow [default = 3.0].

       --khigh <float>
              High threshold in ksigma method (float; default: 3.0). The full name of this option for the EsoRex
              configuration file is fors.fors_img_screen_flat.khigh [default = 3.0].

       --kiter <long>
              Max number of iterations in ksigma method (long; default: 999). The full name of this  option  for
              the EsoRex configuration file is fors.fors_img_screen_flat.kiter [default = 999].

       --xradius <long>
              Median filter x radius (unbinned pixels) (long; default: 50). The full name of this option for the
              EsoRex configuration file is fors.fors_img_screen_flat.xradius [default = 50].

       --yradius <long>
              Median filter y radius (unbinned pixels) (long; default: 50). The full name of this option for the
              EsoRex configuration file is fors.fors_img_screen_flat.yradius [default = 50].

       --degree <long>
              Degree  of  fitting  polynomial  (long;  default: -1). The full name of this option for the EsoRex
              configuration file is fors.fors_img_screen_flat.degree [default = -1].

       --sampling <long>
              Sampling interval for fitting (long; default: 100). The full name of this option  for  the  EsoRex
              configuration file is fors.fors_img_screen_flat.sampling [default = 100].

       Note  that  it  is  possible to create a configuration file containing these options, along with suitable
       default values. Please refer to the details provided by the 'esorex --help' command.

SEE ALSO

       The full documentation for the fors pipeline can be downloaded as a PDF file using the following URL:

              ftp://ftp.eso.org/pub/dfs/pipelines/fors/fors-pipeline-manual-4.9.pdf

       An   overview   over   the   existing   ESO   pipelines    can    be    found    on    the    web    page
       http://www.eso.org/sci/software/pipelines/.

       Basic documentation about the EsoRex program can be found at the esorex (1) man page.

       It   is   possible   to   call   the   pipelines   from   python   using  the  python-cpl  package.   See
       http://packages.python.org/python-cpl/index.html for further information.

       The other recipes of  the  fors  pipeline  are  fors_align_sky(7),  fors_align_sky_lss(7),  fors_bias(7),
       fors_calib(7),     fors_config(7),    fors_dark(7),    fors_detect_objects(7),    fors_detect_spectra(7),
       fors_extract(7), fors_extract_objects(7), fors_extract_slits(7), fors_flatfield(7),  fors_img_science(7),
       fors_img_sky_flat(7),        fors_normalise_flat(7),        fors_photometry(7),       fors_pmos_calib(7),
       fors_pmos_extract(7),  fors_pmos_science(7),  fors_remove_bias(7),   fors_resample(7),   fors_science(7),
       fors_spec_mflat(7),  fors_subtract_sky(7), fors_subtract_sky_lss(7), fors_sumflux(7), fors_trace_flat(7),
       fors_wave_calib(7), fors_wave_calib_lss(7), fors_zeropoint(7)

VERSION

       fors_img_screen_flat 5.3.23

AUTHOR

       Jonas M. Larsen <usd-help@eso.org>

BUG REPORTS

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

LICENSE

       This  file  is  currently  part of the FORS Instrument Pipeline Copyright (C) 2002-2011 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

fors_img_screen_flat                                 5.3.23                              FORS_IMG_SCREEN_FLAT(7)