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A method for recognition of geometrical shapes in auroral forms is presented. The method is based on the analysis of isolines of auroral luminosity shapes. The basic variables used are the angle, (phi) (s), between the tangent of the contour and the x-axis of an arbitrary coordinate system, and the differential, d(phi) (s), as a function of the distance, s, along the contour. The analysis also includes Fourier transformation of the experimental function d(phi) (s) obtained for the observed auroral forms, and the comparison of the power spectrum, F(k), with those for a series of model contours. Some dynamical characteristics of the aurora are also discussed.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
