NAME¶

SubtractSky - subtract the sky value in an image

SYNOPSIS¶

astsubtractsky [OPTION...] ASTRdata

DESCRIPTION¶

SubtractSky is part of GNU Astronomy Utilities 0.2.33-8a3b. SubtractSky Finds the sky value over a grid on the input and subtracts it from the image to give a clear and uniform output.

For more information, please run any of the following commands. They will respectively show you the `Invoking SubtractSky' subsection, the complete `SubtractSky' section, or the full GNU Astronomy Utilities manual. In particular the first contains a very complete explanation of each option.

info astsubtractsky

info SubtractSky

info gnuastro

If you couldn't find your answer in the manual, you can get direct help from experienced Gnuastro users and developers. For more information, please run:

info help-gnuastro

SubtractSky options:

Input:

-h, --hdu=STR

Extension name or number of input data.

-H, --mhdu=STR

Mask image header name.

-k, --kernel=STR

Kernel image file name for convolution.

-M, --mask=STR

Mask image file name.

-U, --khdu=STR

Kernel image header name for convolution.

Output:

--checkconvolution

Store convolved image in `_conv.fits' file.

--checksky

Store final sky and its STD in `_sky.fits' file.

--checkskystd

Include sky standard deviation in all checks too.

-D, --dontdelete

Don't delete output if it exists.

-K, --keepinputdir

Do not remove input's dir info for output.

-o, --output=STR

Output file or directory name.

Mesh grid:

-a, --nch1=INT

Number of channels along first FITS axis.

-b, --nch2=INT

Number of channels along second FITS axis.

--checkmesh

Store mesh IDs in `_mesh.fits' file.

-d, --mirrordist=FLT

Distance beyond mirror point. Multiple of std.

--fullconvolution

Ignore channels in imageconvolution.

--fullinterpolation

Ignore channels in interpolation.

--fullsmooth

Ignore channels in smoothing.

--interponlyblank

Only interpolate over the blank pixels.

-L, --lastmeshfrac=INT

Fraction of last mesh area to add new.

--meshbasedcheck

Each mesh in one pixel in mesh check images.

-n, --numnearest=INT

Number of nearest neighbors to interpolate.

-Q, --minmodeq=FLT

Minimum acceptable quantile for the mode.

-s, --meshsize=INT

Size of each mesh (tile) in the grid.

-T, --smoothwidth=INT

Width of smoothing kernel (odd number).

Statistics:

-t, --sigcliptolerance=FLT Difference in STD tolerance to halt iteration.

-u, --sigclipmultip=FLT

Multiple of standard deviation in sigma-clipping.

Operating modes:

-?, --help

give this help list

--cite

BibTeX citation for SubtractSky.

--nolog

No log file for programs which make one.

-N, --numthreads=INT

Number of CPU threads to use.

--onlydirconf

Only read current directory configuration file.

--onlyversion=STR

Only run if the program version is this.

-P, --printparams

Print parameter values to be used and abort.

-q, --quiet

Only report errors, remain quiet about steps.

--setusrconf

Set default values for this user and abort.

-S, --setdirconf

Set default values for this directory and abort.

--usage

give a short usage message

-V, --version

print program version

Mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options.

GNU Astronomy Utilities home page: http://www.gnu.org/software/gnuastro/

AUTHOR¶

Written by Mohammad Akhlaghi

REPORTING BUGS¶

Report bugs to bug-gnuastro@gnu.org.

COPYRIGHT¶

Copyright © 2015-2016, Free Software Foundation, Inc. License GPLv3+: GNU General public license version 3 or later.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

SEE ALSO¶

The full documentation for SubtractSky is maintained as a Texinfo manual. If the info and SubtractSky programs are properly installed at your site, the command

info SubtractSky

should give you access to the complete manual.