This is the command imstack that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
imstack - AME
SYNOPSIS
imstack [-vi][-o filename][-n num] file1.fits file2.fits ... filen.fits
DESCRIPTION
Stack FITS or IRAF images into single FITS image
or : imstack [-vi][-n num] @filelist -i: Do not put FITS header in output file -n
num: Use each file this many times -m: Write IRAF multispec file -o name: Output
filename -v: Verbose -x root: Make first file root, others extensions
Use imstack online using onworks.net services