SHG (spectroheliography) software release version 3.7

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thesmiths
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SHG (spectroheliography) software release version 3.7

Post by thesmiths »

This most recent version implements a new rectangular cropping feature which makes it easier to do stacking of partial solar disk scans. This feature complements the earlier square cropping feature that addressed stacking for full disk scans. The motivation for this is the fact that the most common stacking software require all the frames to be of exactly the same pixel dimensions.

An improvement was also made in how the curve fitting of the spectral line is done. Near the edge of the solar disk, where the line is quite dark, the program sometimes incorrectly located fitting points. Now outlier points are eliminated, which can sometimes significantly improve the curve fitting, particularly if the ROI of the video is quite wide.

There has also been a minor change to the CLAHE function to improve the performance with very tight crops of the image where very little sky is visible.

The Python source code files can be found here: https://github.com/thelondonsmiths/Sole ... 3.7_Python

As before, a Windows executable file has also been created and can be found here: https://github.com/thelondonsmiths/Sole ... .7_Windows

The Windows executable will run on both Windows 10 and 11. It does not need Python to be installed on the computer. It should run the same as the Python source code v3.7 but without the ability to make any changes to the code. For most people, this Windows executable version will be more convenient to use.

I include here a demonstration of the use case for the new rectangular cropping feature. The data was acquired by Jean-Francois Pettit on 6 November at 13:20 UTC using a 127mm aperture, 1200mm focal length telescope. As this was taken with a standard Solex setup, the slit was only 4.5mm long, therefore Jean-Francois could only scan a stripe at a time and required three passes to cover the entire disk. The new feature allows creating image files of a standard fixed size than can be stacked using, for example, AS!3.

H-alpha SHG processed using software version 3.7
H-alpha SHG processed using software version 3.7
09_56_53_2x2.jpg (367.9 KiB) Viewed 1453 times

The image above is the output of a single SER file. The full stacked and merged image is shown here:

http://www.astrosurf.com/topic/158176-s ... %A8s-midi/


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