一种天波雷达电离层幅相复合污染时频校正方法

A time-frequency distribution correction method for ionospheric amplitude-phase contamination in space-wave OTHR

针对幅度污染和大幅度相位污染导致谱峰重叠的情况,提出一种时频校正方法.根据信号的重排平滑伪Wigner-Ville分布(RSPWD)谱图估计瞬时频率初步校正相位污染,然后自适应提取标校信号并精确校正幅度污染和剩余的相位污染.理论分析和仿真结果表明,该方法所用RSPWD谱图的交叉项比平滑伪Wigner-Ville分布(SPWD)小,校正幅度污染和相位污染残留的计算量比最大似然估计法(MLE)小,可同时校正电离层幅度污染和大幅度相位污染.

This paper proposes a time-frequency correction method as a solution to the peak-overlap caused by amplitude contamination and large-scale phase contamination. This method is used to estimate the instantaneous frequency based on the rearrangement smooth pseudo Wigner-Ville distribution(RSPWD) spectrum to preliminarily eliminate the phase contamination, and then self-adaptively extracts the calibration signal to correct amplitude contamination and residual phase contamination precisely. The theoretical analysis and simulation results show that in the proposed method the cross term of the RSPWD spectrum is smaller than the smooth pseudo Wigner-Ville distribution(SPWD); the calculated amount of correcting the amplitude contamination and phase residual contamination is less than that of maximum likelihood estimation(MLE), and this method can simultaneously eliminate ionosphere amplitude contamination and large-scale phase contamination.