Ionosphere phase decontamination method based on subspace in sky-wave OTHR

In general, ionosphere phase contamination can expand the Bragg peak of sea clutter and the echo signal from a target in sky-wave over-the-horizon radar (OTHR). By exploiting the subspace algorithm, an effective approach of ionosphere phase decontamination is proposed to solve the above-mentioned problems. In this new scheme, the stronger one of two spreading Bragg peaks is extracted by an adaptive sliding-window bandpass filter, and the instantaneous phase of the spreading Bragg peak is obtained by the subspace algorithm. Both the theoretical analysis and the experimental results of the real OTHR data have confirmed the feasibility of this new method.