6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
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An unsupervised deep learning approach to McIntosh sunspot classification

8 Jul 2026, 12:20
20m
Lecture Hall C3 (University of the Western Cape)

Lecture Hall C3

University of the Western Cape

Oral Presentation Track D - Astrophysics & Space Science Astrophysics & Space Science

Speaker

Bernard Swanepoel (School of Computer Science and Information Systems, North-West University)

Description

The McIntosh sunspot classification system categorises sunspots according to their morphology and size. Because this process is typically performed manually, it is susceptible to labeling errors. In contrast, deep learning methods learn features directly from the data and classify samples based on these learned representations. In this paper, an unsupervised approach to McIntosh sunspot classification is presented, and how the models group sunspot data into clusters is examined. These clusters are compared with reference ground-truth labels to determine how strongly they correlate with the ground truth. To assess performance, the supervised models are trained using both the ground-truth labels and the unsupervised labels, and their accuracies are compared. The results indicate that the unsupervised approach outperformed the conventional supervised approach trained on the ground-truth labels. Finally, Local Interpretable Model-agnostic Explanations (LIME) is used to interpret the models' decisions on the unsupervised dataset. The findings highlight the potential for developing an AI-based McIntosh classification framework.

Apply for student award at which level: MSc
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Author

Bernard Swanepoel (School of Computer Science and Information Systems, North-West University)

Co-authors

Ms Calmay Lee (Centre for Space Research, North-West University) Prof. GR Drevin (School of Computer Science and Information Systems, North-West University) Mr JH Grobler (School of Computer Science and Information Systems, North-West University) Prof. RDT Strauss (Centre for Space Research, North-West University) Ruhann Steyn (Centre for Space Research, North-West University)

Presentation materials