Ionospheric multi-paths separation with a high resolution direction finding algorithm mapped on an experimental system

Using a simplified model of waves coming from the ionosphere, the authors show that for an integration time above a few hundred ms, the singularity of the correlation matrix is removed and that the `spatial smoothing techniques´ become unnecessary in most cases. This modelisation takes into account the dynamic and anisotropic effects of the medium, and also the response of receiving antennas. They then describe the experimental system they implemented to evaluate the algorithms. Their measurements prove the ability of the method to separate ionospheric multi-paths and to provide a good estimation of direction of arrival angles. In the case of known emitter location, some ray-tracing procedures, based upon ionospheric predictions and vertical soundings, corroborate the experimental results