Validating prediction packages using superresolution direction finding techniques and oblique ionospheric soundings

In this paper we present AOA (angle of arrival) estimates obtained from data recorded on an eight element L-shaped antenna array for signals that have undergone ionospheric propagation. The AOA estimates obtained are compared with the predicated angles for the propagation path. The advantages of using MLE based techniques over weighted spectrum type approaches have been demonstrated in the multipath environment where signals impinging on the array are correlated. The results show that the MLE is the most useful method to use, in conjunction with sounding techniques and prediction packages, to identify the ionospherically propagating paths. The results also demonstrate that array dimensions have to be carefully selected to minimise the beamwidth of the array at the operating frequency. This is to enable superresolution direction finding techniques to resolve the multipath components