title: A cascaded approach for correcting ionospheric contamination with large amplitude in HF skywave radars.
abstract: Ionospheric phase perturbation with large amplitude causes broadening sea clutter's Bragg peaks to overlap each other; the performance of traditional decontamination methods about filtering Bragg peak is poor, which greatly limits the detection performance of HF skywave radars. In view of the ionospheric phase perturbation with large amplitude, this paper proposes a cascaded approach based on improved S-method to correct the ionospheric phase contamination. This approach consists of two correction steps. At the first step, a time-frequency distribution method based on improved S-method is adopted and an optimal detection method is designed to obtain a coarse ionospheric modulation estimation from the time-frequency distribution. At the second correction step, based on the phase gradient algorithm (PGA) is exploited to eliminate the residual contamination. Finally, use the measured data to verify the effectiveness of the method. Simulation results show the time-frequency resolution of this method is high and is not affected by the interference of the cross term; ionospheric phase perturbation with large amplitude can be corrected in low signal-to-noise (SNR); such a cascade correction method has a good effect.
authors.affiliation: School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Yajun
authors.identifier: 0000-0002-1500-1829
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Yinsheng
authors.initials: Y
authors.lastname: Wei
authors.affiliation: School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Rujiang
authors.initials: R
authors.lastname: Guo
authors.affiliation: School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Rongqing
authors.initials: R
authors.lastname: Xu
authors.affiliation: School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Zhuoqun
authors.identifier: 0000-0003-1839-8419
authors.initials: Z
authors.lastname: Wang
authors.affiliation: School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Xiudong
authors.initials: X
authors.lastname: Tang
mesh_terms: D000465:Algorithms; D001272:Atmosphere / Q000737:chemistry*; D003198:Computer Simulation; D008962:Models, Theoretical; D011825:Radar; D013997:Time Factors