Classification of Equatorial Ionospheric Irregularities Using Unsupervised Machine Learning Based on Spatiotemporal ROTI Keograms. - Gleb Mutasov; Pornchai Supnithi; Jirapoom Budtho; Napat Tongkasem; Michi Nishioka; Septi Perwitasari; Lin Min Min Myint (IEEE J. Sel. Top. Appl. Earth Obs. Remote. Sens., 2025)