【作者】 冯威；

【导师】 黄丁发；

【作者基本信息】 西南交通大学 ， 大地测量学与测量工程， 2013， 博士

【摘要】 随着GPS定位技术的不断深入发展,尤其是网络RTK定位技术的出现以及CORS观测网络建设的普及,广域范围内厘米级的实时动态定位服务已经成为现实。然而对于高精度位置监控方面的应用,如高精度实时动态形变监测、精细农业和自动化机械施工等,常规RTK定位技术已不能很好的满足此类实际应用的需求,具体表现为：常规RTK定位的差分计算工作在流动站端设备上完成,(监控)服务器无法获得流动站完整的位置信息；用户端设备需具备载波相位差分计算模块,增加了实际应用的成本；不利于流动站间观测数据的融合处理与分析,也不利于进一步研究、挖掘数据之间所潜在的重要信息。基于上述的分析,本文对中央差分定位技术进行了深入研究。中央差分定位模式中,所有GPS测站的观测数据都回传至中央差分服务器,并由服务器端完成位置解算。中央差分定位技术不仅可提供常规RTK定位服务,获取完整的用户位置信息,同时还可提供多样化的数据处理策略,以满足特殊的位置服务需求。中央差分定位技术与常规RTK定位技术形成互补之势,两者共同发展将有助于进一步完善GPS定位的理论框架,提高其应用层次。本文主要针对GPS中央差分定位系统所涉及的理论与方法,研究了系统的框架结构,对其中某些关键技术提出了改进算法,并最终初步实现了GPS中央差分定位系统。论文的主要研究内容与创新点概述如下：1、概括了GPS定位技术的研究现状,分析了传统RTK定位技术与中央差分定位技术的优缺点,总结了中央差分系统的研究意义。2、阐述了网络RTK定位模式与中央差分定位模式的系统框架组成及特征,对两者进行了对比分析,并详细阐述了中央差分定位系统的主要构成与关键技术。3、阐述了GPS实时数据质量控制的研究内容与方法流程；提出了一种改进的电离层残差周跳探测与修复方法,方法可直接探测与修复对应频率上载波相位观测值的周跳,其对1周的周跳有较好的探测能力；将时间基线用于动态环境下的粗差探测,时间基线粗差探测法可无需已知模糊度信息,其在试验条件下可探测出0.15周的单个粗差。4、总结了三类模糊度解算方法,即基于测量域的模糊度解算、基于坐标域的模糊度搜索以及基于模糊度域的模糊度搜索方法；提出了双频整周关系约束模糊度解算方法(FirCAR),在局部范围内FirCAR将模糊度的等效波长扩大至了L1波长的9倍,通过试验分析了方法的可行性与适用性；同时给出了基于FirCAR的快速动态模糊度初始化方法,并与LAMBDA方法进行了试验对比分析5、介绍了大范围动态变形监测的两种常用方法：PPP动态定位技术与长距离RTK定位技术,并分析了两者在强震监测中的不足；基于GPS空间误差的时空相关性,提出了高频GPS双差残差模型动态位移监测方法,一条长为1100km基线的静态数据试验结果表明,该方法在预测5分钟内N、E、U方向动态位移精度分别为6mm、6mm和13mm; E1Mayor-Cucapah7.2级地震GPS测站观测数据进一步证明了该方法的可行性与可靠性。6、初步研制了一套GPS中央差分定位软件系统,系统主要包括实时数据流解码模块、基线数据解算模块、数据存储模块以及可视化显示与数据分析模块,并分别通过24小时的静态GPS观测数据、20分钟的动态观测数据以及E1Mayor-Cucapah7.2级地震的94个GPS站的地震数据,对系统在形变监测、动态位置监控以及地震地表动态位移监测方面的应用进行了试验,结果表明该系统是一个能够连续运行、多点监测、高精度和高可靠性的位置信息监控服务系统。更多还原

【Abstract】 With the development of the network real-time kinematic (NTRK) technology, wide area centimeter-level real-time kinematic (RTK) positioning service becomes true. However, the standard RTK positioning technology can not well meet the needs of high-precision position monitoring applications, such as kinematic deformation monitoring, precision agriculture, automated machinery construction. Firstly, since the differential computation is carried out by the rover, the (monitoring) server can not obtain the full information of the rover’s position. Secondly, the capability of differential computation of the carrier phase measurement is required on the user-side device, and the additional requirements will cause an increase in cost. Lastly but not the least, the standard RTK positioning technology is not conducive to the data fusion and overall analysis of the observations from different rovers, and even be against the further research and potential information mining.Central differential positioning technology is studied in this dissertation. Observations from all sites are sent back to the central differential positioning server, in which the differential computation is then carried out. The central server can provide standard RTK service, obtain the whole positioning information, and even deploy different data processing strategies to satisfy special location-based services. To give full play to their own advantages and cooperate with each other, the central differential positioning technology, along with the standard RTK positioning technology, will further improve the level and extent of GPS theoretical study.This dissertation focuses on the theory and methods involved in the central differential positioning system. The framework structure of the system is studied, the algorithms of some key techniques are improved, and the system is initially implemented. The main research contents and innovations are summarized as follows:1、Current research status of GPS positioning technology, the advantages and disadvantages of the standard RTK and the central differential positioning technology are analyzed. The significance of the central differential positioning system is also summarized.2、The system frame structure and the characteristics of the NRTK positioning and the central differential positioning are presented. The main components and key technologies of central differential positioning system are elaborated.3、Research contents and methods of GPS real-time data quality control are presented. A modified ionospheric residual cycle slip detecting and repairing method is proposed, which can detect and repair the carrier phase cycle slip for a specific frequency, and can deal with the small cycle slip of one cycle. Time baseline is employed to detect the outlier of carrier phase measurements for the kinematic application. Outliers of0.15cycles can be detected under the experimental conditions, without the need of ambiguity fixing.4、Different ambiguity resolution methods have been summarized, including ambiguity resolution/searching in measurement domain, in coordinate domain, and in integer ambiguity domain. Dual-frequency integer relationship constrained GNSS ambiguity resolution (FirCAR) method is proposed. FirCAR increases the equivalent wave length of the integer ambiguity up to9times of wave length of L1. The feasibility and applicability is experimentally tested. On the fly (OTF) ambiguity resolution method based on FirCAR is also presented, and it is also experimentally compared with LAMBDA.5、Wide range kinematic deformation monitoring methods are presented, including the kinematic precise point positioning (PPP) and the long range RTK positioning technology. Kinematic deformation monitoring method using double-differenced residuals model for high-rate GPS is proposed. Experimental results from a static baseline of about1100km show that the standard deviation of the kinematic position are6mm,6mm and13mm for N, E and U, respectively, in the predicted5minutes. The feasibility and reliability of the proposed method are further verified by GPS data obtained during El Mayor-Cucapah M7.2earthquake.6、GPS central differential positioning software system has been preliminarily developed. The system mainly includes the real-time data stream decoding module, the baseline processing module, the data storage module, and the visual analysis module. A24-hour static data set, a20-minute kinematic data set, and the data sets of the94GPS stations during El Mayor-Cucapah M7.2earthquake have been used, to test the functions of deformation monitoring, the kinematic positioning monitoring, and the seismic ground surface kinematic displacement monitoring, respectively. Experimental results show that, the proposed location information monitoring service system is capable of continuous operation, multiple locations monitoring, high precision and high reliability.更多还原