Since I want to use Siril to calculate FWHM in my Bachelors thesis I wanted to find out how Siril fits the gaussian function around a star. I looked at the source code, but I am not well versed in c so I can’t quite make sense of it and it does not quite resemble the way I know of how to fit gaussian functions to measure star FWHM as far as I can tell.
G(x,y)=B+Aexp( −((x−xi)^2 +(y−yi)^2) /2σ^2) this is the formula I know of, but the form used in the source code seems to have a slightly different form.
I would just need the basic gaussian function the software uses, so I can put it in my thesis. Thank you!
Hello, I’m not the one who wrote this code, which was made in Matlab and converted to C if I remember correctly, but you may find information on this page if you haven’t seen it already: Siril:PSF - FreeAstro . Indeed it’s not easy to understand, as it’s mostly arranging data into matrices and vectors to let GSL solve the thing in the end…
Just to let you know, I’ve updated the link, it was leading to a badly formatted page. Also, I’ve just created that about aperture photometry: Siril:Photometry - FreeAstro