Astrophysics (Index)About

point-spread function

(PSF)
(function describing an optical system's response to a point of light)

A point-spread function (PSF) describes the response of an optical system (such as a telescope) to incoming light from a point, consisting of a mathematical function describing the light-pattern expected on the focal plane, i.e., mapping relative position on the focal plane to the received EMR flux that would come from a point source. Such a function describing an Airy disk is an example. Theories have been developed regarding types of mathematical functions specific to particular aperture shapes (e.g., rectangles, slits, circles) and sizes: masks are sometimes used with telescopes producing various shapes because non-circular apertures in some cases reveal data obscured by circular apertures.

PSF subtraction (for point spread function subtraction) is a type of post-processing aimed at isolating the Airy disk of a specific star. Airy disks from images of lone stars taken with the same instrument (or even within the same image) are used to help sort out the images of stars-of-interest that have overlapping Airy disks.


(telescopes,optics,function)
Further reading:
https://en.wikipedia.org/wiki/Point_spread_function
https://zeiss-campus.magnet.fsu.edu/articles/basics/psf.html
https://www.telescope-optics.net/diffraction_image.htm
https://mathworld.wolfram.com/AiryFunctions.html
https://www.stsci.edu/hst/instrumentation/wfc3/data-analysis/psf
https://jwst-docs.stsci.edu/jwst-near-infrared-camera/nircam-performance/nircam-point-spread-functions
https://www.ctio.noirlab.edu/~atokovin/tutorial/part1/turb.html

Referenced by pages:
Jeans anisotropic modeling (JAM)
PSF fitting
speckle suppression

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