An upgraded method for reconstructing 3-dimensional structure of aurora from stereo images

Abstract

We have been studying reconstruction of auroral 3-D luminous structure from stereo images. We have used the model function method for this problem. In this method, auroral structure is expressed by an appropriate function with some parameters, which are determined by iterative calculations. The auroral model assumes sheet-like luminosity structure with some prescribed thickness and altitude distributions. In this paper, we present an upgraded model function which can express an aurora of more complicated structure. The upgraded model is expressed by the product of a 2-D function which represents projections of an aurora along the geomagnetic lines of force onto the horizontal plane and an altitude function along the geomagnetic line of force. Using this model, curved aurora arcs and pulsating auroras of irregular form can be more properly delineated. In this paper, we analyze the aurora arc observed in Iceland and a pulsating aurora observed in Antarctica. At the same time, we examine the appropriateness of the functional form which expresses the altitude profile of the luminosity of aurora based on theoretical prediction.