融合非同步星地异构GNSS、测高和DORIS观测的全球电离层TEC实时精确监测方法

全球电离层TEC实时精确反演是推动空间电离层天气应用的基础与核心。以北斗/GNSS、测高卫星和DORIS等为代表的电离层观测存在的“非同步”问题以及“星地异构”特点，严重制约其在实时模式中的应用效能。针对此，本项目拟通过发展“建模+预测”的循环迭代处理策略，将非同步观测的贡献延拓至当前历元；结合星地异构特点，设计各类系统误差的序贯处理和动态调整方法，削弱残余误差的无限累积进而导致解算不稳定的影响；借鉴“虚拟观测”和“大网处理”思想，大幅提高实时解算效率；在此基础上，建立实时模式下利用非同步星地异构观测进行电离层TEC反演的系统解决方案，在全球范围内实现优于3TECu的反演精度；结合典型应用进行编码播发和服务模式的设计，开展试验验证和国际推广。. 相关成果不仅可进一步丰富卫星导航电离层监测的理论和方法，而且推动北斗在电离层监测领域的落地应用，具有重要的科学和现实意义。

Real-time global ionospheric total electron content (TEC) modeling and monitoring using the asynchronous observations from ground- and space-based multi-GNSS, Altimetry and DORIS techniques constitutes the fundament and basis of various ionospheric space weather applications. However, the use of BDS/GNSS, Altimetry and DORIS observations for real-time ionospheric TEC modeling is pronouncedly affected by their asynchronous characteristics, i.e., different time latencies, accuracies and observable types (absolute versus relative TECs and slant versus vertical TECs) within the respective observations. To extend the asynchronous observations with different time latencies to the same ionospheric modeling epoch, a prediction-plus-modeling iterative processing strategy is first proposed. To inhibit the infinite accumulation of the modeling residuals caused by the systematic offsets between multitype ground- and space-based observations, a sequential processing and automatic adjustment method is designed. Additionally, the consideration of pseudo-observations and large network processing is applied to improve the efficiency of real-time ionospheric TEC modeling with multitype observations. The systematic solution for the real-time global ionospheric TEC modeling and monitoring with multitype ground- and space-based asynchronous observations is expected to be achieved, which shall exhibit an overall accuracy of 3.0 TECu on a global scale. Finally, the experimental verification and application will be focus of the proposal by designing appropriate schemes for real-time ionospheric information coding and broadcasting with the consideration of typical application scenarios. . The achievement of the proposal shall not only enrich the theory of real-time ionospheric modeling with multi-GNSS techniques, but also facilitate the application of BDS navigation satellite system for ionospheric space weather monitoring, which exhibits the important theoretical and the practical significance for both GNSS and ionosphere research fields.