astsubtractsky1

Subtract the sky value in an image

Usage

astsubtractsky [OPTION ...] ASTRdata

Overview

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/