Multifractal identifying and characterization of ionospheric propagation modes

The dynamic nature of the high latitude ionosphere leads to the formation of small-scale ionospheric irregularities capable of scattering HF radio waves. The large-scale irregularities were identified by many models, however, small-scale irregularities are not well identified and characterized. The aim of this paper is to present a new wavelet-based multifractal approach to identify the ionospheric propagation modes and to localize the small irregularities and quantify it by a multifractal dimension mapping. We have adopted the scattering function as a tool for the ionosphere channel characterization. The non homogeneity of the scattering function expressed according to the time propagation and Doppler shift led us to split it into two one dimensional vectors. Applying the scaling analysis to the two vectors, we have deduced a cut-off scale for wavelet decomposition used for the multifractal analysis. Our analysis was performed over experimental scattering functions of the ionospheric channel obtained with an experimental support: STU-DIO station installed near to Paris. Results will be very useful for further ionosphere modeling.