Ionospheric Decontamination for Sky-wave Radars Based on General Parameterized Time-Frequency Transform

General parameterized time-frequency transform is introduced to analysis the echo of sky-wave over-the-horizon radar, a more effective and robust method for ionospheric decontamination is developed. We choose the spline function as kernel function of general parameterized time-frequency transform according to the characteristics of ionospheric contamination. Aiming at the ionospheric contamination, the parameters of kernel functions are estimated. Then the ionospheric contamination sequence is calculated from the kernel functions, and based on which the decontamination operator is obtained, the contamination can be removed. For the multiple mode propagation situations, by the way of iterative decontaminating-then-filtering, contamination can also be removed. Lastly, the effectiveness and robustness of the method are verified by the numeric simulations.