电离层不均匀体多维度表征与时空活动机理及影响研究

Ionospheric irregularities refers cloud block structure in the ionosphere with different electron density, the electron density in ionospheric irregularities is higher or lower than the average electron density of the surrounding medium. Ionospheric irregularities lead to amplitude attenuation and phase jitter of satellite navigation signals, affect satellite navigation system performance. Characterization of ionospheric irregularities, activity mechanism and the mechanism of interaction of ionospheric irregularities with satellite navigation signal have been under focus in the related research field. To address the problems existing in current studies, which are concluded as incomprehensive description for intrinsic features, incomplete understanding for activity rule, unclear mechanism for coupling effects and imperfect methods for its effects evaluation, this project will propose multi-physical multi-dimensional ionospheric irregularities features characterization method, deeply analyze time-space correlated mechanism of ionospheric irregularities activities, investigate the multiple layer, cascaded and dynamic coupling effects between ionospheric irregularities and satellite navigation signals, and finally discover ionospheric irregularities impacts on satellite navigation system performance and application, referred as its space weather effects resolution and evolution. Experiments and tests will be conducted to verify our theory and methods, to completely reveal scientific mechanisms of ionospheric irregularities. This project will provide a theoretical basis and technical support for the relevant scientific research and national strategic needs.

电离层不均匀体指电离层中具有不同电子密度的云块状结构，其电子密度高于或低于周围介质电子密度平均值。电离层不均匀体导致卫星导航信号传播幅度衰减、相位抖动，影响卫星导航系统性能。电离层不均匀体的表征、活动机制和与卫星导航信号的相互作用机理受到相关研究领域的密切关注。本课题针对现有电离层不均匀体及其与导航信号耦合作用的研究中所存在的本质特征描述不全面、活动规律认知不完整、耦合作用机理不清晰、影响程度分析不系统等科学问题开展研究，建立多物理量多维度的电离层不均匀体特征表征方法，深入剖析电离层不均匀体活动的时空关联机制，挖掘电离层不均匀体与导航信号传播和性能变化的多层次、级联、动态耦合机理，并在此基础上探寻电离层不均匀体对卫星导航应用的空间天气效应演化模型，同时开展实验验证，以全面揭示电离层不均匀体的科学规律，为相关科学研究和国家战略需求提供理论基础和技术支撑。

电离层不均匀体的形成和时空活动是相关领域的热点和难点问题，为此本项目开展了电离层不均匀体多维度表征与时空活动机理方面的研究，构建了电离层不均匀体的时空分布特征，研究了极端空间天气事件下电离层不均匀体的演化规律，分析电离层不均匀体与卫星导航信号的耦合作用机理，电离层闪烁导致信号接收失锁的时空变化和季节规律，建立了电离层不均匀体和电离层总电子含量的全球预测模型。通过项目开展，完成了对电离层不均匀体产生原因、时空活动规律及其对卫星导航信号和性能的影响的全面认知，发表SCI学术论文8篇，申请国家发明专利6项，获国家发明专利授权2项。项目开展过程中与国际相关领域的研究学者开展了深入广泛的学术交流。项目成果可为全面认知电离层不均匀体的科学本质提供理论支撑、为电离层不均匀体引起的卫星导航信号接收难题提供技术指导，具有一定的科学和工程应用价值。