综合观测值组合与网解处理的多频率GNSS信号偏差建模与估计

Multi-frequency and multi-system GNSS provide users with more abundant observation information, and the complex signal biases between multi-class observation values is the key and difficult point in the high-precision data processing of multi-frequency and multi-system GNSS. This topic proposed to carry out the theory and method research of multi-frequency and multi-system GNSS signals biases modeling and estimation. It is intended to study the mechanism and classification of GNSS signal biases from the perspective of hardware and signal processing. Analyze the characteristics and variation rules of different signal biases related to time, space and receiver hardware. Breaking through the key technologies such as the establishment of the empirical model of signal biases and the estimation of signal biases under the unified benchmark, we provide users with high-precision signal biases correction products of "empirical model + deviation file" under the unified benchmark. The expected results have important research significance for improving the processing level of satellite clock error estimation, ionospheric delay extraction, un-difference ambiguity resolution, and improving the performance of BDS/GNSS positioning, navigation and timing service.

多频率多系统GNSS为用户提供了更丰富的观测信息，同时多类观测值之间复杂的信号偏差是多频率多系统GNSS高精度数据处理的关键与难点。本课题围绕多频率多系统GNSS信号偏差精确建模与参数估计问题，拟开展：从硬件和信号处理层面研究GNSS各类信号偏差产生机制和分类；分析不同类型信号偏差与时间、空间、接收机硬件等相关的特性及变化规律；突破统一基准下信号偏差经验模型建立和偏差估计等关键技术，为用户提供统一基准下“经验模型+偏差文件”的高精度信号偏差改正产品。预期成果对提高卫星钟差估计、电离层延迟提取、非差模糊度固定等处理水平，提升北斗/GNSS定位、导航和授时服务性能具有重要研究意义。

随着全球导航卫星系统（GNSS）多系统多频率的发展，GNSS观测信号不断丰富，但同时也带来了各类信号偏差问题。在此背景下，项目组申请了综合观测值组合与网解处理的多频率GNSS信号偏差建模与估计项目，并按计划完成了相关研究。.针对多频率多系统GNSS信号偏差类型多样问题，利用GNSS信号模拟器、实测的零/短基线和MGEX网等基准站数据，对GNSS信号偏差进行验证。根据偏差产生机制和特性对多频率多系统数据处理中的相关的偏差进行梳理与分类。.针对具有规律性的信号偏差建模问题，对于空间因素相关、与时间因素相关和与卫星-接收机类型相关的信号偏差特性进行分析，根据特性分析结果，建立了不同卫星系统的频间钟偏差模型、不同卫星系统和接收机类型的信号畸变偏差经验改正模型。.针对统一基准下信号偏差估计问题，在改正信号偏差经验模型的基础上，基于非差非组合方法，构建的信号偏差可估数学模型，实现了统一基准下伪距和相位偏差估计，并基于基准站网长期数据进行重处理。.基于上述GNSS信号偏差先验改正模型与产品，研制并更新GNSS高精度数据处理软件模块。结合实测多频率多系统GNSS基准站数据，项目组的信号偏差模型显著提升了卫星钟差估计、电离层延迟提取、多频非差模糊度固定和终端精密定位等数据处理精度。