【作者】 高乐；

【导师】 成英燕； 郑作亚；

【作者基本信息】 山东科技大学 ， 大地测量学与测量工程， 2011， 硕士

【摘要】 全球卫星导航定位技术和地球观测系统在21世纪的蓬勃发展,将会使人类对地球的认识达到前所未有的高度,这样就迫切需要以最符合地球运动规律的方一式规定地球参考系统,并建立可供使用的地球参考框架。20世纪90年代以来,以全球导航卫星系统(GNSS)为主的现代空间定位技术迅猛发展,地面为主测量技术也发生了根本性变革,迫切需要一种高精度、地心、动态、统一的大地坐标系统作为位置测量的参考系。在此期间,国际大地测量协会(IAG)所属的国际GNSS服务中心(IGS)适时向全球提供了全球地心参考框架ITRF,并在建立国家地球参考框架和区域性地球参考框架方面作了大量卓有成效的工作。为适应全球地心坐标系统的发展趋势,我国与2008年正式启动了地心坐标系统——2000国家大地坐标系统(CGCS2000)。本文基于CGCS2000,初步探讨了建立和维持我国自主地球参考框架所需关键技术和方法,并利用28个国家级CORS站数据建立了CGCS2000板块运动模型。主要的贡献和研究成果如下：(1)系统介绍了协议地心参考框架的有关内容。参考框架问题实质上是一个坐标系问题。包括国际地球参考系统及参考框架,尤其是最新的国际地球参考框架ITRF2008,2000国家大地坐标系等坐标系统,并详细介绍及解释了它们之间的关系,特别是ITRF、CGCS2000以及它们之间的转换方法。(2)对于地球参考框架基准统一,提出了一种将局部区域数据纳入ITRF的新方法。基于新旧两个坐标参考框架下不同历元的台站坐标与速度,以及新旧框架之间的7个转换参数和转换参数变率的偏导关系,旧框架下的坐标与速度的协方差阵可以严密转换到新框架下。以此为基础,在相同历元下,忽略速度和转换参数变率的影响,对上述过程进行适当简化,实现了基于相同历元的坐标协方差阵的严密框架转换。通过这种方法,能够使局部区域数据不必重新处理就能纳入ITRF框架,方便利用国际上已有的数据成果。实例表明,使用该种方法,转换后的坐标偏差优于0.1mm,完全能够满足框架之间转换的要求。对于不同框架间的数据统一,具有一定的借鉴意义。(3)介绍了板块运动模型基本原理,总结了国内外对中国地区的板块运动研究。在此基础上,对中国大陆及周边进行了板块的重新划分。板块构造运动有两个基本假设：①板块具有刚性,其内部并不发生明显的塑形形变。②板块构造学说主张,地球表面积(或地球半径)并未发生过显著的增加或减小。基于这两个假设,可以引入欧拉定律来描述板块运动。板块运动的研究方法可分为地质与地球物理方法和空间大地测量方法两类。使用这两种方法国内外的研究学者建立了多个不同了运动模型,国际上比较成熟的有NUVEL1A、PB2002、APKIM2005等全球板块运动模型,我国学者也基于ITRF建立了ITRF97VEL、ITRF2000VEL等模型；同时对中国大陆细化,建立了我国一、二级板块运动模型。在建立模型的过程中,板块边界的确定直接关系到所建模型的精度,本文在国内外对我国地壳运动研究的成果上,对我国及周边进行了重新板块划分,确定了7个一级块体。(4)参考框架点的方法研究。目前,使用现代空间大地测量技术,选取国际地球参考架(ITRF)和板块运动模型台站的标准具有随意性,直接影响地球参考架和板块运动模型的精度和可信度。本文在前人研究的基础上,总结了一种确定刚体板块内稳定台站选取的系统方法,即首先分析各台站的数据质量,然后利用7参数法进行精选,并对精选台站进行监督分类,最后使台站空间分布均匀化,以此选择GNSS数据处理中的IGS框架点。(5) CGCS2000板块运动模型的建立及结果分析维持CGCS2000主要考虑因素是板块的构造运动,本文利用28个国家级CORS站水平方向的站坐标与速度建立了基于CGCS2000的板块运动模型,其模型精度达到厘米量级,与国内外的其他模型(ITRF、NUVEL1A、PB2002、APKIM2005、我国学者符养对中国大陆地区等建立的运动模型)相比也显示了较高的精度。更多还原

【Abstract】 The technology of global satellites navigation and positioning and earth observation has been rapidly developing, which will help people more deeply understand earth, so it’s urgent to define the Terrestrial Reference System according to the best discipline of the earth’s motion and establish Terrestrial Reference Frame to provide service.From 1990s, modern aerospace technology mainly included the global navigation satellite system (GNSS) has been developing rapidly, and the observation technology mainly observed the earth’s surface has also a fundamental change,so it’s urgent to need a high-precision, geocentric, dynamic, uniform coordinate system as a reference system for position measurement. In the meantime, International GNSS Service (IGS) provides international terrestrial reference frame (ITRF). IGS belongs to International Association of Geodesy (IAG) and does a great amount of work for the establishment of national reference frame and local reference frame. In order to fit the trend of development of geocentric coordinate system, our country start formally using geocentric coordinate system---China Geodetic Coordinate System(CGCS2000).This paper initially attempts to discuss how to establish and maintain our country’s terrestrial reference frame, and applies 28 national-level CORS stations to establish plate motion models based onCGCS2000.Main contribution and research results are as follows:(1)systematically introduce the academic contents of consultative geocentric reference frame.Reference frame is a substantially coordinate system. This paper systematically introduces the contents about ITRS/ITRF, especially new terrestrial reference frame ITRF2008, CGCS2000 and their relation between them, especially the rigid transformation between ITRF and CGCS2000.(2)In order to realize unifying principle of terrestrial reference frame, this paper puts forward a new method of data in local area network brought into ITRF.Based on the partial derivatives relationship of coordinates and velocities at different epoch along with 7 transform parameters and their rates between two reference frames, variance-covariance matrices of station coordinates and velocities in an old frame can be transformed into a new frame by a rigorous transformation method. On the basis of it, this paper ignores the influence of velocities and 7 transform parameters rates and simples the above process to realize the variance-covariance matrices of station coordinates between two reference frames at the same epoch. By the method, local area data can be brought into ITRF and avoid data processing repeat simultaneity. Moreover it’s convenient to use directly international data products existed in the Internet. Analyzing the results of the example, discover that the transformed coordinates deviation can excel 0.1mm level, which can meet the transformation request between two reference frames. This paper can be used for reference to unite data in different reference frames.(3)Introduce the basic principle of plate motion models, and summarize the research about plate motion in the area of China at home and abroad. Based on that, the area of China and circumjacent is repartitioned again.There are two basic hypothesizes of plate tectonics motion:①Plate has the rigidly physical property, and there is no clearly plastic deformation in the inside of plate.②The theory of plate tectonics motion claims that superficial area of earth(or radius of earth) has no clear increase or reduction. Based on those hypothesizes, Euler law can be lead in to describe plate motion. Research methods of plate motion can be divided into two categories, namely, geology and geophysics method and space geodesy method. Using the two methods, researchers at home and abroad establish many motion models, for instance, at abroad there are many world models such as NUVEL1A、PB20、APKIM2005,while our country’s researchers established ITRF97VEL、ITRF2000VEL and so on.In the process of plate motion models establishment, the determine of plate boundary is in relation to the precision of final models, so based on the research at home and abroad, the area of China and circumjacent is repartitioned again in this paper, totally 7 plate blocks(4) The method study of reference frame stationsThe stations constrained on international terrestrial reference frame (ITRF) with modern space geodetic techniques are chosen with some random and uncertainties, which directly affects the precision and reliability of ITRF. This paper summarizes a system method to select stations on the rigid plate. Namely, firstly, analyse the quality of data at each station. The second step is rigorous selection to use 7 parameters transformation. The third step is supervision clustering to eliminate some stations that is largely affected by local diastrophism. Finally, make stations well-proportioned spacial distribute. By the method, IGS frame station can be chosen in GNSS data processing to establish high precision terrestrial reference frame.(5) The creation of CGCS2000 plate motion models and result analysisIn order to maintain CGCS2000, main factors to consider is plate tectonics motion, this paper use horizontal direction data of 28 national-level CORS to establish CGCS2000 plate motion models, which reaches cm-level accuracy and has more high accuracy than other models such as ITRF, NUVEL1A、PB2002、APKIM2005 and other research production at home.更多还原