ZOGY in Parallel¶
A python package for image subtraction, registration, and co-addition
About¶
ZOGY in Parallell (ZiP) is a fast(ish) computation of proper image subtraction B.Zackay, E.Ofek, A.Gal-Yam (2016). Inspired by Ofek (2014) and pmvreeswijk. ZiP offers a faster subtraction at the expense of a more comprehensive input. I.e. The program should be tailored for one telescope or input of images. This code has a parallell function, however it requires 6+ cores to operate. This particular Case is optimised for the Gravitational-Wave Optical Transient Observer (GOTO) However, simple fudging of the parameters should make it possible to make this work for other telescopes.
Left: is the D-output image. Right: Scorr image.
An internal version of Spalipy has been added as the alignment algorithm. This uses sextractor to find source locations in two images and then aligns them with an affine transform. Residuals are then used to build a 2D spline surface to correct for warping due to large field distortions.
Finally, a parallel version of proper coadition is used for stacking images. It still isn’t increadibly fast for on the spot coaddition; so a meidian combine tool is also included.
Basic Usage¶
ZiP can now be used in the terminal:
ZOGY file.fits ref-file.fits
#------------------------------------------------
#Takes Comprehensive inputs too now
ZOGY file.fits ref-file.fits -sub_imagex 2 -sub_imagey 2
In the shell use:
ZOGY -help
For a list of helpful parameters
You can also import zogyp into python:
#You can also make your own scripts
import zogyp
zogyp.zip.run_ZOGY(sci,ref)
This will do the subtraction (sci - ref) and return the subtracted in an output directory called Zoutput.
The output consists of the D_image, S_image, and Scorr_image.
There is a comprehensive tutorial on GitHub
Ry Cutter
Version 1.6.3 (25/02/2020)