Optimization And Implementation Of Ionospheric Incoherent Scattering Radar Parameter Inversion Algorithm

Space science and technology is one of the competitive focuses of the world’s major scientific and technological powers,and it is also one of the important areas to provide national security,drive national scientific and technological progress,stimulate social and economic development,and improve national cohesion and centripetal force.As one of the players at the forefront of space science and technology competition in the world,our country has successively launched a number of strategic space projects such as manned spaceflight,space station,lunar exploration and return,and Mars exploration this year.The development of these projects has greatly safeguarded my country’s national security,boosted my country’s economic development,and enhanced national pride.The research of space science and technology is guided by the knowledge and understanding of the space environment.Therefore,all major aerospace powers have invested a lot of manpower and material resources to detect and study the space environment.The space-based swept-frequency stepping radar working in the low frequency band is one of the next technological hotspots in space exploration.Since the sweptfrequency stepping radar represented by Radio Plasma Imager and DSX of the United States and MARSIS of ESA has been put into use,it has greatly promoted human’s understanding and understanding of the space environment.Our current project officially try to develop a major scientific research instrument "Spaceborne Radio Plasma Detection System" from 2018.The goal is to design and manufacture an ultrawideband space-based swept-frequency stepping radar with a working frequency band of 3k Hz-3MHz.Prototype,the detection area includes the ionosphere,inner magnetosphere,etc.The Earth’s radiation belts are one of the hot spots in the target area.High-energy particles in the radiation belt are one of the major threats to the electronic equipment of spacecraft and the personal safety of astronauts.However,the high-energy electrons enriched in the extraterrestrial radiation belt move fast,and their relativistic effect is significant,so the parametric inversion algorithm of the swept-stepped radar based on the radio wave propagation model in the traditional cold plasma cannot be directly applied to the detection of the outer radiation belt.In this study,starting from the equation of motion of relativistic electrons,the dispersion relation model of relativistic electrons in the extraterrestrial radiation belt is established.Propagation,reflection,refraction and other transmission characteristics are compared with the transmission characteristics of radar signals in the ionosphere,and the algorithm principle suitable for plasma parameter inversion in the extraterrestrial radiation belt is sorted out.Combined with satellite observation data,the model is carried out different simulation analysis.The first chapter of this paper introduces the relevant research background and research status at home and abroad.The second chapter makes a mathematical derivation of the radio wave propagation model and dispersion relation in cold plasma.In the third chapter,the relativistic effect is introduced,and the physical modeling of the radar signal propagation in the outer radiation belt is carried out.Based on the model,the radar signal propagation characteristics in the outer radiation belt are analyzed and discussed.The factors and mechanisms of radar signal propagation characteristics are analyzed and discussed.In chapter 4,combined with the observation data of Van Allen Probes and other satellites,the propagation characteristics of radar signals in the radiation belt outside the storm time are studied through simulation experiments.In chapter 5,we give our summaries and provide ideas for follow-up work.