The detection and characterisation of the solar UV network

Paterson, Rhys Leigh (2016) The detection and characterisation of the solar UV network. MSc(R) thesis, University of Glasgow.

Abstract

High resolution images of the Sun taken at UV wavelengths show the presence of a fine network like structure across the solar disc. This UV network contributes to the total power radiated by the Sun so it is clear that a study of it is of great interest. This thesis deals with the development of an automated method to quantify the covering percentage of this network in the hopes that this could lead to greater insights into the nature of said network. Chapter 1 serves as an introduction to the Sun and the field of solar physics with a specific focus on the UV network and the processes leading to its existence. We also discuss the general motivations for solar research as whole and the particular interest in the UV network. Finally we describe the SDO satellite, and its instruments, used to gather the data used throughout this work. Chapter 2 discusses the intricacies of the data itself and the various calibration and preparation processes it has undergone between the raw data itself and the Level 1 data made available for research. We then describe the preparation of three images to be used to test all our developed algorithms on. Chapter 3 deals with the presence of solar limb darkening and the possible issues caused by its presence. We develop and evaluate several methods to counter the limb darkening, before determining the final algorithm to be used before any network detection takes place. In Chapter 4 we describe the development of several methods to detect the UV network. We then attempt to determine which of these detection algorithms is the most suitable for use on large data sets. Chapter 5 discusses the results observed when applying our selected detection algorithm to several years worth of data. From these results we discuss the behaviour of the UV network and its correlation with other methods of solar variability. In Chapter 6 we discuss whether, and to what extent, we have met the original targets of this thesis work. We then go on to explore the problems that were encountered throughout our research before finally outlining future work that could be done to further and improve upon our results.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Solar network, network detection, mathematical morphology, UV.
• Subjects: Q Science > QB Astronomy
• Colleges/Schools: College of Science and Engineering > School of Physics and Astronomy
• Supervisor's Name: Fletcher, Professor Lyndsay
• Date of Award: 2016
• Depositing User: Mr Rhys L Paterson
• Unique ID: glathesis:2016-7260
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 26 Apr 2016 08:01
• Last Modified: 09 Aug 2019 15:58
• URI: https://theses.gla.ac.uk/id/eprint/7260