Review of image quality measures for solar imaging
| Autor: | Valeri G. Orlov, Krystian Radlak, Krzysztof Bernacki, Adam Popowicz |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Physics
Fried parameter Image quality FOS: Physical sciences Astronomy and Astrophysics 02 engineering and technology Iterative reconstruction Lucky imaging 01 natural sciences law.invention Telescope Space and Planetary Science law 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Median filter Discrete cosine transform 020201 artificial intelligence & image processing Astrophysics::Earth and Planetary Astrophysics Astrophysics - Instrumentation and Methods for Astrophysics 010303 astronomy & astrophysics Algorithm Instrumentation and Methods for Astrophysics (astro-ph.IM) Energy (signal processing) |
| Popis: | The observations of solar photosphere from the ground encounter significant problems due to the presence of Earth's turbulent atmosphere. Prior to applying image reconstruction techniques, the frames obtained in most favorable atmospheric conditions (so-called lucky frames) have to be carefully selected. However, the estimation of the quality of images containing complex photospheric structures is not a trivial task and the standard routines applied in night-time Lucky Imaging observations are not applicable. In this paper we evaluate 36 methods dedicated for the assessment of image quality which were presented in the rich literature over last 40 years. We compare their effectiveness on simulated solar observations of both active regions and granulation patches, using reference data obtained by the Solar Optical Telescope on the Hindoe satellite. To create the images affected by a known degree of atmospheric degradation, we employ the Random Wave Vector method which faithfully models all the seeing characteristics. The results provide useful information about the methods performance depending on the average seeing conditions expressed by the ratio of the telescope's aperture to the Fried parameter, $D/r_0$. The comparison identifies three methods for consideration by observers: Helmli and Scherer's Mean, Median Filter Gradient Similarity, and Discrete Cosine Transform Energy Ratio. While the first one requires less computational effort and can be used effectively virtually in any atmospherics conditions, the second one shows its superiority at good seeing ($D/r_0 submitted to Solar Physics |
| Databáze: | OpenAIRE |
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