1. Multi-scale CLEAN in hard X-ray solar imaging
- Author
-
Volpara, Anna, Piana, Michele, and Massone, Anna Maria
- Subjects
Astrophysics - Solar and Stellar Astrophysics ,FOS: Mathematics ,FOS: Physical sciences ,Numerical Analysis (math.NA) ,Mathematics - Numerical Analysis ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,45Q05, 47A52, 68U10, 8508 ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
Multi-scale deconvolution is an ill-posed inverse problem in imaging, with applications ranging from microscopy, through medical imaging, to astronomical remote sensing. In the case of high-energy space telescopes, multi-scale deconvolution algorithms need to account for the peculiar property of native measurements, which are sparse samples of the Fourier transform of the incoming radiation. The present paper proposes a multi-scale version of CLEAN, which is the most popular iterative deconvolution method in Fourier space imaging. Using synthetic data generated according to a simulated but realistic source configuration, we show that this multi-scale version of CLEAN performs better than the original one in terms of accuracy, photometry, and regularization. Further, the application to a data set measured by the NASA Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) shows the ability of multi-scale CLEAN to reconstruct rather complex topographies, characteristic of a real flaring event.
- Published
- 2023