DETECTION OF LOCALIZED STRUCTURES FROM MULTISPACECRAFT DATA - ADAPTIVE CORRELATION-FUNCTION

When several spacecraft pass at different distances from a localized s tructure like a field-aligned current tube, the corresponding magnetic signatures recorded on each spacecraft generally show different times cales, due to the different ''viewpoints'' of the spacecraft. For this reason, it is impossible to identify the presence of a unique structu re from these signatures by using the classical correlation functions. In this paper, we present an ''adaptive correlation function'' which is a new analysis tool allowing to look for such ''correlations'' what ever the dilation factor is between two signals.