高精度GNSS地学应用的空间天气效应研究

Currently, high-quality GNSS based geodetic services are urgently required for studying some significant Earth' science problems related to global environmental change, resource exploration and natural hazard monitoring. To achieve this, the effect of space weather on GNSS positioning and orbital determination is one of the main error sources in high-precision GNSS applications for the Earth's science. In view of this, the following research will be made: multi-frequency/ multi-system GNSS (MM-GNSS) data quality control and processing, precise/specific local geoma- gnetic modeland MM-GNSS based precisely determining and modeling multi-scale ionospheric TEC and electron density, precise mathematic express of modeling the effects of multi-scale space weather in MM-GNSS observations, and the theories and methods of correcting for or reducing the effects of space weather on precise GNSS positioning(such as precise point positioning (PPP),precise relative positioning (PRP) and so on) and orbital determination (including multi-system GNSS and GNSS based LEO satellites)for high-precision applications relate to the Earth's science. Based on the above achievements (theories, models and methods), it is convinced that the related key issues will be solved(or to some degree) as follows: what are the main principles or characteristics of the temporal and spatial distributions of the effects of space weather on GNSS observations and precise GNSS positioning and orbital determination for GNSS/ GNSS-based LEO satellites and how to rapidly and precisely process MM-GNSS data, how to MM-GNSS based precisely determine ionospheric information, and what is the exact process of the residual effects of space weather in the above positioning and orbital determination. Some valuable conclusions will be obtained about the above problems. Therefore,the key achievement in this project will be the theories and methods of analyzing, modeling, and reducing the effects of multi-scale precise space weather on MM-GNSS signal and its applications in the Earth's services. It is also be convinced that the whole research will further develop the theories and methods of modern GNSS baaed geodetic data processing, precise positioning and orbital determination, and some results are also available especially for development and application of COMPASS(the up-coming Chinese GNSS system).

适应全球环境变化、资源勘探、自然灾害监测中相关重大地球科学问题研究对高精度GNSS测量成果的迫切需求，围绕如何有效克服空间天气效应对GNSS测量精度的制约、提高现代GNSS技术在地学问题研究中的应用效能，系统开展GNSS数据质量控制与处理、电离层/地磁场信息精确求定与处理、空间天气效应精确模拟及表示、精密定轨定位的空间天气效应修正理论方法等研究，力求解决GNSS测量的精细空间天气效应的时空分布与显现规律及其制约精密导航定位定轨的主要特征以及多频多模GNSS数据快速高效精确处理、电离层信息精确确定、精密定位定轨的空间天气影响过程与机制等相关理论问题。发展有特色的精细空间天气效应分析模拟及修正理论与方法，丰富GNSS数据处理及精密定位定轨理论与方法，提升GNSS技术在地学研究中的精密应用效能，深化现代大地测量与空间天气学交叉研究，也为我国北斗等新一代全球卫星导航系统建设提供相关理论与方法。

GNSS测量的精细空间天气效应（主要指高阶项电离层延迟）严重影响现代GNSS技术精密测量精度和应用效能，制约相关地球科学前沿问题的深入研究。本项目系统开展了GNSS 数据质量控制与处理、电离层/地磁场信息精确求定与处理、空间天气效应精确模拟及表示、精密定轨定位的空间天气效应修正理论与方法等方面的研究，主要包括：（1）构建了充分顾及我国北斗系统特点并兼容其它GNSS系统的全球电离层TEC格网建立方法SHPTS，总体精度优于国际同类产品精度，以该技术为核心建立了国际电离层TEC分析中心（之一）；（2）提出有特色的多模GNSS频间偏差（DCB）处理方法，精度达到国际同类先进水平，以该技术为核心建立了国际IGS DCB分析中心（全球第二家）；（3）提出并建立被我国北斗全球导航系统采纳使用的广播电离层时延修正模型，中国卫星导航系统管理办公室在北斗卫星导航系统空间信号接口控制文件中以中英文两种形式在向国内外发布；（4）构建了一种新的北斗卫星太阳光压摄动力解析模型，被国际IGS/MGEX工作组技术报告认为是北斗三代全球导航系统精密定轨的代表性成果，推动了多系统联合精密定轨与服务研究发展；（5）提出采用非组合精密单定位方法估计空间天气效应影响，提高GNSS长基线相对精密定位精度。利用上述研究成果参与建立和维持亚太地区坐标参考框架，提供的亚太参考框架坐标精度优于其他国际同类中心，获联合国全球地理信息管理亚太区域委员会正式批准建成了国内首个亚太参考框架分析中心，承建了中国第二代卫星导航系统专项管理办公室立项的“iGMAS北斗分析中心”任务（即北斗数据分析中心，国家首批之一）等。 . 项目成果为项目负责人牵头成功申请到科技部重点研发计划项目和王宽诚率先人才计划卢嘉锡国际团队项目提供了重要的理论与方法支持。项目组获得国家科技进步二等奖 1项、湖北省科技进步奖一等奖1项；共发表用论文86 篇（SCI收录44篇，EI收录28篇），获国家发明专利授权1项，软件登记4项；培养中青年科技创新领军人才1人与国家“万人计划”领军人才1人、引进中国科学院百人计划1人；项目负责人受邀成为国际大地测量权威学术期刊《Journal of Geodesy》编委，受邀继续担任IGS电离层工作组成员；培养博士生/硕士生16名/11名、培养博士后1名；66人次参加国际学术会议，27人次参加国内学术研讨会。