Sunspot Number Calculation Using Clustering

We present a method for automatically detecting the number of sunspots and sunspot groups in standardized images of the Sun. We use adaptive thresholding to isolate the sunspots, and data clustering techniques to classify them into groups. By working on both the MDI Continuum and Magneto gram images, our method groups those sunspots together which originate from the same magnetic flux loop. To the best of our knowledge, such a method has not been used for Sunspot group analysis. To measure the accuracy of the algorithm, we compute the Sunspot Number for each image of the sun and compare that with standard results available on the Space Weather website. As our results show, this calculation can be done with competent accuracy.