Clustering of lightning discharges
The paper discusses cluster analysis methods for identifying and finding the main parameters of a thunderstorms. Unlike many statistical procedures, cluster analysis methods are used in most cases when there are no a priori hypotheses about classes and the researcher is in the descriptive stage of the study. To solve the problem, it is proposed to use successively two methods of cluster analysis using the Mahalanobis metric and the normalized еuclidean metric. The results obtained using the first method do not contradict the data used in modern theory and practice, but, nevertheless, require a certain accuracy in determining the shape of a cluster. This is due to the fact that, on the one hand, as a result of the use of certain algorithms, “fibrous” clusters are created, in other words, clusters of elliptical shape. On the other hand, thunderstorm clouds in the shape of an ellipse do appear on the fronts, called frontal thunderstorms. In this case, the shape of the hearth is determined by the air flow, pushing against a thunderstorm cloud on the leeward side, giving it an oval shape. The use of the second method makes it possible to exclude noise in the construction of maps of densities of lightning discharges and to improve the accuracy of determining parameters during lightning registration by passive radio engineering methods.