SOLARNET Conference: The Many Scales of the Magnetic Sun

Point-spread functions in solar physics

Not scheduled

20m

Haus H, Telegrafenberg

Poster presentation 1) Latest facilities to observe fundamental processes - space missions, telescopes, and instrumentation Latest facilities to observe fundamental processes - space missions, telescopes, and instrumentation

Speaker

Stefan Hofmeister (Leibniz Institute for Astrophysics Potsdam)

Description

Point-spread functions (PSF) describe the scattering and diffraction of light within an instrument. Deconvolving an image with the PSF enables one to correct for these instrumental effects. We revised the PSF of AIA, work on the PSF of EUI, developed a new, faster PSF deconvolution method, and checked the effects on different datasets. For AIA-193, the intensity of active regions increases by 20-50%, whereas within coronal holes 80% of the intensity is scattered from its surrounding. In HMI magnetograms, the magnetic field strength of magnetic elements increases by 50%, the magnetic field strength of coronal holes increases by 20%, and the doppler velocities by 50%. The change depends on the size of the structure and its internal signal distribution, and as such, these changes cannot be considered as a simple multiplicative factor. Therefore, it can be expected that these changes will also affect more complex data products, such as magnetic field extrapolations.