Journal Article

Motion Magnification in Solar Imaging Data Sequences in the Sub-pixel Regime

Nakariakov, Valery M., Duckenfield, Timothy J., Anfinogentov, Sergey A., Zhong, Sihui

2021

Overview

The capability of the motion-magnification technique for the detection of transverse oscillations, such as kink oscillations of solar coronal loops observed with an imaging telescope, in the sub-pixel regime is investigated. The technique is applied to artificial-image sequences imitating harmonic transverse displacements of the loop, observed in the optically thin regime. Motion magnification is found to work well on the analysis of sub-pixel, ≥ 0.01  pixel oscillations, and it is characterised by linear scaling between the magnified amplitude and input amplitude. Oscillations of loops with transverse density profiles of different steepness are considered. After magnification, the original transverse profiles are preserved sufficiently well. The motion-magnification performance is found to be robust in noisy data, for coloured noise with spectral indices ranging from 0 to 3, and additional Poisson noise with a signal-to-background-noise ratio down to unity. Our findings confirm the reliability of the motion-magnification technique for applications in magnetohydrodynamic seismology of the solar corona.

• Publisher: Springer Netherlands,Springer Nature B.V
• Subject: Amplitudes / Astrophysics and Astroparticles / Atmospheric Sciences / Background noise / Corona / Coronal loops / Fluid flow / Helioseismology / Magnetohydrodynamic (MHD) Waves and Oscillations in the Sun’s Corona and MHD Coronal Seismology / Magnetohydrodynamics / Noise / Physics / Physics and Astronomy / Pixels / Seismology / Slopes / Solar corona / Solar imagery / Solar oscillations / Solar physics / Space Exploration and Astronautics / Space Sciences (including Extraterrestrial Physics / Transverse oscillation