An Approach for Correction of Ionosphere Phase Contamination Based on Covariance Matrix Recounstruction in Skywave Radar Systems

For skywave radar, the radar echo will suffer from phase contamination as they propagate through the time-varying ionosphere, which will lead to serious clutter spectrum spread in long Coherent Processing Interval. It increases the difficulty of the slow-speed target detection and limits the skywave radar performance. In this paper, a decontamination method based on covariance matrix reconstruction is proposed. In this new approach, the stronger one of two Bragg peaks is extracted by an adaptive band-pass filter, then the decontamination function is obtained by the covariance matrix reconstruction. Theoretical analysis and simulation results show that the new scheme is effective and computationally efficient under both slow and fast phase fluctuation.