Аннотация:Methods of mathematical morphology (MM) have been actively developed due to the practical need to solve problems of automatic recognition of objects on TV images, in cartography and computer vision. Ground-based optical auroral observations have a number of features (strong aspect-angle distortion, low contrast, lack of a clear boundary, etc.) that must be considered when spatial and temporal structure of the auroral glow are analyzing by the MM methods. The report discusses the basic MM definitions and application of the MM methods to obtain the spatio-temporal characteristics of pulsating auroral arcs.