• How to convert solar image from telescope into spherical coordinates

    From a a@21:1/5 to All on Fri Oct 7 12:32:25 2022
    Looking for JavaScript tool to work for HTML5 on smartphone in web
    browser to get 2D flat image from a telescope live processed into 3D
    spherical image to generate heat maps and calculate total energy emitted indexes

    What data structure is fit to save spherical imaging ?

    In theory, I can process 2D flat image saved into data array and filter
    out pixels representing image of the Sun (solar disc) for postprocessing
    and for any given pixel (x,y), I need to calculate its distance from the
    center of the solar disc and multiply its grey or RGB value by a reversed factor, reducing the area of a circle on the surface of a sphere when
    projected onto a 2D flat surface.

    Ok, in theory and practice I can wait hours to have sunspots or sunspot
    groups detected at the edge of the solar disc to turn and move more into
    center of the disc for the verification, the above concept is fair, not generating extra overheads in sunspot energy values

    Let me know your opinion

    thank you \ darius

    [[Mod. note -- There is a software package HEALPix which could probably
    be used to do this, but this may be "overkill" and it would certainly
    take some programming. I downloaded a copy of HEALPix in 2016 (but never
    did anything with it); at that time it had bindings for C, C++, Fortran 90, Python, IDL, and Java (but not Javascript). My notes say that back then
    it lived at
    and was described in some detail in the paper
    G\'{o}rski et al,
    "HEALPix: A Framework for High-Resolution Discretization
    and Fast Analysis of Data Distributed on the Sphere"
    Astrophysical Journal 622, 759
    preprint: arXiv:astro-ph/0409513
    -- jt]]

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)