aquila astrophotography package

aquila is a package designed to be a minimalist tool for initial steps of astrophotography data processing. There is a shortage of easy to use tools for Linux. Moreover, most tools in existence do not work well from terminal, which is a natural tool for managing and organizing hundreds of image files during stacking etc. Popular tools like IRAF are not friendly for quick use by amateur astronomers. aquila is intended to fill that void.

Currently, the package consists of following programs:

aqstack for stacking and reduction of monochromatic CCD images
aqlrgb for compositing images from many filters into one color picture

Usage

Use option -h or -help to get the information below.

aqstack

usage: aqstack [STRATEGY] [OPTIONS] FILE1 [FILE2 ...] -o OUTPUT
STRATEGY can be: bias, dark, flat, process, align, final
      -o/-output FILENAME  specifies the output filename
                 -average  stack by average value
                  -median  stack by median
                 -sigclip  stack by 3-sigma clipped average
          -align [METHOD]  align frames (isometric). METHOD can be:
                           polygon: quadrangle matching {def.}
                           gravity_only: use gravity align method
                           gravity: use polygon matching and fine-tune
                           using gravity
            -ref FILENAME  align to this frame rather than first frame
   -resample [FACTOR=1.5]  resample before stacking (only with -align)
                           FACTOR is scale to be applied
             -norm[alize]  normalize to average before stacking
                -no-stack  process but do not stack images
        -suffix/-S SUFFIX  suffix that will be added to file names
                           when using -nostack {def.: _r}
   -temp/-T TEMP [DT=0.5]  stack only frames with given CCD temperature
                           DT gives allowed deviation in temperature
                           in Celsius
           -bias FILENAME  subtract this master bias
           -flat FILENAME  remove this master flat
           -dark FILENAME  remove this master dark
    [-no]-hot [SIGMA=5.0]  find hot pixels on dark and correct them
                           in the image frames (if dark is given) {def.: ON}
           [-no]-hot-only  do not remove dark, just correct hot pixels
                           {def.: OFF}
[-no]-darkopt [SIGMA=5.0]  optimize dark to minimize correlation
                           if sigma is nonzero, only background will be used.
                           SIGMA=0 forces to use all pixels {def.: OFF}
         [-no]-dirty-dark  subtract bias from dark (only if not done before!)
                           {def.: OFF}

aqlrgb

prepares the aligned images for RGB processing
usage: aqlrgb [L] R G B [-o FILE] [options]
R, G, B are color frames and L is optional luminance
            -o/-output  specifies the output file name
                        (allowed formats: fits, png)
                -split  save as 3 files fits rather than one cube
                        for example, if image.fits is given to -o, three files
                        image.r.fits, image.g.fits, image.b.fits will be written
        -smooth [FWHM]  smoothes color while preserving luminance
                        if FWHM not given, default value (2.5) will be used
         -wb/-equalize  attempt to make stars white
                        (works best if background is small)
       -bg/-background  attempt to make background black
                        (do not use for strong nebulosity)
     -sqrt/-asinh/-log  compress the image levels before saving
  -sqrt2/-asinh2/-log2  same but using luminosity
                        (boosts star colors but can kill some details)
               -h[elp]  prints help

Changelog

210111: removed flux ratios, changed triangles to quadrangles
210109: auto-flip, polygon align
210104: dark optimization (simple), cleaning dark from bias
210103: hot pixels are corrected when dark is loaded
200717: hot pixel correction
200716: now temperature filter is before loading images, which saves memory

Planned Features