基于地基GNSS观测数据的电离层延迟改正研究

发布时间：2018-08-14 09:13

【摘要】：电离层作为地球空间环境的重要组成部分，对无线电导航信号的正常传播造成干扰，尤其是对单频导航用户影响较大，已成为全球卫星导航系统（GNSS）中最为棘手的误差源之一。基于地基GNSS观测数据可以建立全球电离层延迟模型从而实现有效修正电离层延迟误差的目的。此外，电离层建模方法还能够较为精确地获取卫星及接收机的硬件延迟参数（DCB-Difference Code Bias），从而为精密定位提供服务。目前国际上大多采用GPS观测资料进行电离层建模且集中在事后处理方面，实时电离层产品方面的研究甚少。我国的北斗二代导航系统自2012年7月正式提供服务以来，已完成了区域导航定位服务的布施。考虑到不同导航系统间的兼容互操作性，非常有必要研究北斗系统的电离层修正产品，从而为北斗高精度导航定位服务提供技术支撑。基于上述出发点，本文开展了基于地基GNSS观测数据建立全球电离层延迟模型的研究，并在此基础上，基于球冠谐函数研究实现了中国区域电离层延迟实时产品修正。另外，考虑到目前北斗测站较少无法单独建模的现状，提出采用联合GPS/BDS地基数据进行全球电离层建模，以精确的北斗卫星DCB参数产品。本文的主要研究内容和取得的成果可归纳如下： 1.研究总结了基于地基GPS观测数据利用球谐函数进行全球电离层延迟建模的原理、数据处理方法和参数估计策略； 2.研究实现了利用GPS地基观测数据进行全球电离层TEC格网模型建立，并进行了卫星和接收机硬件延迟偏差的精确估计；通过实验分析，，采用本文所获得的电离层和DCB产品与国际IGS发布的产品精度相当； 3.研究实现了基于GPS/BDS双系统观测数据进行全球电离层联合建模的方法，并精确估计了我国北斗二代卫星和接收机的DCB参数；并在北斗单频单点定位中加入本文所获得的北斗DCB产品对定位精度分析验证了所获北斗电离层和DCB产品的精度和有效性； 4.借助于球冠谐函数及我国的陆态网络数据建立了我国区域电离层模型，并在此基础上研究实现电离层延迟的实时修正方法，分析了实时电离层产品的精度和可靠性；
[Abstract]:As an important part of the geospatial environment, the ionosphere interferes with the normal propagation of radio navigation signals, especially for single-frequency navigation users. It has become one of the most intractable error sources in the global satellite navigation system (GNSS). The global ionospheric delay model can be established based on ground-based GNSS data to effectively correct the ionospheric delay error. In addition, the ionospheric modeling method can obtain the hardware delay parameters (DCB-Difference Code Bias),) of satellite and receiver accurately. At present, the ionospheric modeling based on GPS observation data is mostly used in the world, and the research on real-time ionospheric products is rare. Since the second generation navigation system of Beidou in our country officially provided service in July 2012, it has completed the regional navigation and positioning service. Considering the compatibility and interoperability among different navigation systems, it is necessary to study the ionospheric correction products of Beidou system, so as to provide technical support for Beidou high-precision navigation and positioning service. Based on the above, a global ionospheric delay model based on ground-based GNSS observation data is developed, and the real time product correction of ionospheric delay in China is realized based on the spherical crown harmonic function. In addition, considering the fact that the Beidou station can not be modeled separately at present, a global ionospheric model based on joint GPS/BDS ground data is proposed to produce precise Beidou satellite DCB parameters. The main contents and achievements of this paper can be summarized as follows: 1. The principle, data processing method and parameter estimation strategy of global ionospheric delay modeling based on ground-based GPS observation data using spherical harmonic function are summarized. 2. In this paper, the global ionospheric TEC grid model based on GPS ground-based observation data is established, and the precise estimation of the delay deviation between satellite and receiver hardware is carried out. The ionospheric and DCB products obtained in this paper have the same accuracy as those released by the international IGS. The method of global ionospheric modeling based on GPS/BDS double system observation data is studied and the DCB parameters of the second generation satellite and receiver of Beidou in China are estimated accurately. The accuracy of Beidou ionospheric and DCB products is verified by adding the Beidou DCB product to the Beidou single frequency and single point positioning. 4. Based on the spherical crown harmonic function and the land state network data in China, the regional ionospheric model of China is established. Based on this, the real-time correction method of ionospheric delay is studied, and the accuracy and reliability of real-time ionospheric products are analyzed.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P228.4

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