College of Mathematics and Physics Guangxi University for Nationalities Nanning 530006 China;
School of Information Engineering Baise University Baise 533000 China;
Key Laboratory for Ionospheric Observation and Simulation Guangxi University for Nationalities Nanning 530006 China;
School of Information Engineering Baise University Baise 533000 China;
College of Mathematics and Physics Guangxi University for Nationalities Nanning 530006 China;
College of Mathematics and Physics Guangxi University for Nationalities Nanning 530006 China;
College of Mathematics and Physics Guangxi University for Nationalities Nanning 530006 China;
College of Mathematics and Physics Guangxi University for Nationalities Nanning 530006 China;