---
name: "fors_remove_bias"
section: "7"
platform: "linux"
package: "cpl-plugin-fors-doc"
version: "5.5.6+dfsg-4"
release: "Debian 11 (Bullseye)"
platforms: ["linux"]
url: "https://new.carta.tech/fors_remove_bias"
---

# fors\_remove\_bias(7)

Subtract bias from input frame

## NAME

fors\_remove\_bias - Subtract bias from input frame

## SYNOPSIS

esorex **fors\_remove\_bias** \[OPTIONS\] FILE.sof

## DESCRIPTION

This recipe is used to subtract the overscan and master bias(produced by the recipe fors\_bias) from one raw data frame. The overscan regions, if present, are used to compensate for variations of the overall bias level between master bias and input raw frame. The overscan regions are then trimmed from the result.

The recipe should allow any fors frame.

Input files:

  DO category:               Type:       Explanation:         Required:\
   ANY\_CAT\
                   Raw         Raw data frame          Y\
   MASTER\_BIAS                Calib       Master bias frame       Y

Output files:

  DO category:               Data type:  Explanation:\
   ANY\_CAT\_UNBIAS             FITS image  Bias subtracted frame

## OPTIONS

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 **https://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 **https://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/7.md), [*fors\_align\_sky\_lss*(7)](/fors_align_sky_lss/7.md), [*fors\_bias*(7)](/fors_bias/7.md), [*fors\_calib*(7)](/fors_calib/7.md), [*fors\_config*(7)](/fors_config/7.md), [*fors\_dark*(7)](/fors_dark/7.md), [*fors\_detect\_objects*(7)](/fors_detect_objects/7.md), [*fors\_detect\_spectra*(7)](/fors_detect_spectra/7.md), [*fors\_extract*(7)](/fors_extract/7.md), [*fors\_extract\_objects*(7)](/fors_extract_objects/7.md), [*fors\_extract\_slits*(7)](/fors_extract_slits/7.md), [*fors\_flatfield*(7)](/fors_flatfield/7.md), [*fors\_img\_science*(7)](/fors_img_science/7.md), [*fors\_img\_screen\_flat*(7)](/fors_img_screen_flat/7.md), [*fors\_img\_sky\_flat*(7)](/fors_img_sky_flat/7.md), [*fors\_normalise\_flat*(7)](/fors_normalise_flat/7.md), [*fors\_photometry*(7)](/fors_photometry/7.md), [*fors\_pmos\_calib*(7)](/fors_pmos_calib/7.md), [*fors\_pmos\_extract*(7)](/fors_pmos_extract/7.md), [*fors\_pmos\_science*(7)](/fors_pmos_science/7.md), [*fors\_resample*(7)](/fors_resample/7.md), [*fors\_science*(7)](/fors_science/7.md), [*fors\_spec\_mflat*(7)](/fors_spec_mflat/7.md), [*fors\_subtract\_sky*(7)](/fors_subtract_sky/7.md), [*fors\_subtract\_sky\_lss*(7)](/fors_subtract_sky_lss/7.md), [*fors\_sumflux*(7)](/fors_sumflux/7.md), [*fors\_trace\_flat*(7)](/fors_trace_flat/7.md), [*fors\_wave\_calib*(7)](/fors_wave_calib/7.md), [*fors\_wave\_calib\_lss*(7)](/fors_wave_calib_lss/7.md), [*fors\_zeropoint*(7)](/fors_zeropoint/7.md)

## VERSION

fors\_remove\_bias 5.5.6

## AUTHOR

Carlo Izzo \<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