蒙古国坐标系统的介绍及在地质勘探中的应用

介绍了蒙古国大地控制网和转换参数,控制网坐标系统包括国家坐标系(pulkovo1942)、地方坐标系、GPS坐标系(Monref97),并且介绍了各个坐标系统之间的转换参数,以及在工程中坐标系统的应用。     

全球大地测量地心坐标参考框架最新进展

较为系统地介绍了2003年7月在日本札幌举行的第23届IUGG大会上世界各国所报告的各自国家大地 测量地心坐标参考框架的实施和最新进展。具体结合欧洲、非洲和日本等国的地心坐标系统详细介绍了这些国家 在该领域所开展的工作,对我国今后地心坐标框架的建设和维护提出了一些有益的建议。     

GCRS与ITRS的两种坐标转换模型计算与比较

地心天球参考系(GCRS)与国际地球参考系(ITRS)之间有两种坐标转换模型:基于春分点的岁差章动转换和基于CIO的无旋转原点转换。IERS 2003和2010规范针对这两种转换模型分别推荐了相应的转换参数。以DE421历表中太阳系10个天体为例,计算并分析了两种坐标转换模型之间、以及两个规范之间的差异对于坐标转换的影响。结果表明:对于同一个规范而言,两种坐标转换模型之间的差异对坐标转换的影响在5μas以内;对于同一种坐标转换模型而言,两个规范之间的差异对坐标转换的影响在0.5 mas以内。     

ADS40数字航空摄影测量技术中坐标系统转换和大地水准面精化成果的应用研究

利用ADS40三线阵推扫式数字航摄仪进行航空摄影作业时,其机载GPS和地面基站GPS获取的观测数据经处理后的成果为WGS84坐标系统,而我们测绘的数字线划图(DLG)、数字正射影像图(DOM)、数字高程模型(DEM)往往是建立在西安80坐标系统或地方独立坐标系统下,因此,ADS40数字航摄仪后期数据处理的一个重要的工作就是:通过坐标系统转换得到西安80坐标系或地方独立坐标系的平面坐标;通过大地水准面精化模型得到国家85高程。一、坐标系统转换的数学模型ADS40数据后处理软件,坐标系统转换的实质内容是将WGS84大地坐标转换为西安80大地坐标,其…     

GNSS互操作若干问题

GNSS兼容与互操作是国际卫星导航领域的热点议题,也是用户实现多系统融合导航必须具备的条件。本文首先介绍了兼容与互操作的基本概念;简要分析了多GNSS系统互操作的基本趋势及GNSS4大核心系统信号互操作的现状;分析了现有北斗卫星导航系统(BDS)在信号互操作方面存在的问题,指出其对用户接收机制造商和多GNSS用户的影响;分析了坐标基准和坐标框架在互操作方面存在的问题及其可能带来的影响,指出坐标系统的实现、维持甚至更新策略带来的误差都可能给多GNSS互操作及导航定位结果带来影响;讨论了时间基准互操作存在的问题,以及可能的解决措施。最后归纳了本文的主要结论。     

四参数坐标转换的方法及应用

介绍了四参数坐标转换的原理以及南方CASS软件、中海达RTK手簿和中海达HDS2003数据处理软件解算四参数的方法 ;以宝鸡市蟠龙塬70 km~2测区中8个已知控制点为基础,解算出坐标转换的四参数,并进行了精度分析,为测量工作提供了依据。     

中山市连续运行卫星定位服务系统运行维护及功能简介

首先介绍了中山市连续运行卫星定位服务系统的基本情况,包括架构组成和运行维护,其次是它的特色功能:在线实时坐标转换,可以实时得到中山市统一坐标和1985国家高程;最后介绍了应用与推广情况。     

不同坐标系统平均空间重力异常之间差别的研究

研究了不同系统平均空间重力异常之间的差别 ,认为是坐标、椭球参数及正常重力公式引起的差别 ,但主要是坐标系统不同引起的。我国大地坐标系统下的 5′× 5′平均空间重力异常与地心纬度系统的相比 ,相差几十毫伽相当普遍。椭球参数和正常重力公式的影响在我国一般不超过± 3 m Gal(1Gal=1cm/s2 )。不同坐标系统引起的平均空间重力异常之间的差别无法进行简单而精确的转换     

基于Global Mapper的数字地图坐标系统转换

介绍了Global Mapper中投影/坐标系统的定义方法,以MicroStation DGN格式数字地图坐标系统转换为例,给出了利用Global Mapper实现数字地图坐标系统转换的方法和步骤,并对转换结果进行了分析。     

我国大地测量及卫星导航定位技术的新进展

综述我国大地测量及卫星导航定位技术的新进展,介绍近几年我国大地测量工作取得的重要成果:坐标系统的建立、维护和更新;卫星定位技术的发展应用;地壳运动监测与大地测量地球动力学研究进展;(似)大地水准面精化研究进展。     

卫星重力场探测及空间和地面大地测量联合观测

国际大地测量与地球物理联合会(IUGG)第廿四届大会于2007年7月上旬在意大利举行,本文结合这次大会对重力卫星CHAMP、GRACE和GOCE的目前概况作简要介绍,对它们在探测地球重力场方面的进展进行了评述。对国际大地测量协会(IAG)提出的"全球大地测量观测系统GGOS"和"整合空间大地测量技术作为全球大地测量和地球物理观测系统的基础GGOS-D"项目中"共点"测量的重要性进行了评述,并对这类共点测量成果解算应注意事项进行了介绍。最后将国际大地测量与地球物理联合会(IUGG)主席和秘书长在第廿四届大会开幕式上的报告和答记者问摘编后作为本文附录供参考。     

National Committees Officers of the International Association of Geodesy

National Committees Officers of the International Association of Geodesy Nominations for IAG officers, 1991–1995     

中国大地测量的数据处理要科学界定潮汐改正计算

中国大地测量的现行规范细则中 ,凡涉及潮汐改正计算的都采用全潮汐改正 ,所以相应的数据处理和大地成果就相应于无潮汐值 ,如无潮汐重力值、无潮汐水准高、无潮汐垂线偏差、无潮汐高程异常值 ,甚至由此涉及无潮汐地壳等。这项改正曾经受到 1979年国际大地测量协会 (IAG)堪培拉 (Canberra)大会有关决议的支持 ,但随后不久 ,IAG就作了改正 ,在 1983年汉堡 (Hamburg)大会上仍以决议形式修正了它原来的意见 ,转而对零潮汐改正表示支持。国际大地测量界对潮汐改正的研究几经反复 ,近十年来已取得了比较一致的意见 ,即认为采用零潮汐改正是比较科学的 ,特别是对以陆地国土为主的国家更为合适。因此 ,中国在制定新的大地测量基准的有关条例和相应的各种大地规范细则时 ,应及时修正原来的无潮汐改正的规定 ,确定采用零潮汐改正 ,使全国在这方面的数据处理和所得大地成果纳入更为科学的轨道     

The International VLBI Service for Geodesy and Astrometry (IVS): current capabilities and future prospects

Very Long Baseline Interferometry (VLBI) plays a unique and fundamental role in the maintenance of the global (terrestrial and celestial) reference frames, which are required for precise positioning in many research areas such as the understanding and monitoring of global changes, and for space missions. The International VLBI Service for Geodesy and Astrometry (IVS) coordinates the global VLBI components and resources on an international basis. The service is tasked by the International Association of Geodesy (IAG) and International Astronomical Union (IAU) to provide products for the realization of the Celestial Reference Frame (CRF) through the positions of quasars, to deliver products for the maintenance of the terrestrial reference frame (TRF), such as station positions and their changes with time, and to generate products describing the rotation and orientation of the Earth. In particular, VLBI uniquely provides direct observations of nutation parameters and of the time difference UT1-UTC. This paper summarizes the evolution and current status of the IVS. It points out the activities to improve further on the product quality to meet future service requirements.     

On-line Resources Supporting the Data, Products, and Information Infrastructure for the International DORIS Service

The International DORIS Service (IDS) was formed under the direction of the International Association of Geodesy (IAG) in 2003 to support geodetic research utilizing DORIS data and products. The IDS is organized into a hierarchy of components: network of Tracking Stations, Satellite Segment, Data Centers, Analysis Centers, Central Bureau, and Governing Board. The DORIS infrastructure consists of a globally distributed network of over 50 ground beacons and a constellation of five satellites equipped with receivers that relay range rate measurements through a central collection facility to the IDS archives. The Data Centers and Central Bureau supporting the IDS are the primary means of distributing DORIS data, products, and general information to the user community. These facilities utilize Web and ftp servers, as well as an email service, to support the users of DORIS data and products. The current status and recent developments of these components are discussed, as well as a review of available information, data, and geodetic product types.     

The International Association of Geodesy 1862 to 1922: from a regional project to an international organization

Geodesy, by definition, requires international collaboration on a global scale. An organized cooperation started in 1862, and has become todays International Association of Geodesy (IAG). The roots of modern geodesy in the 18th century, with arc measurements in several parts of the world, and national geodetic surveys in France and Great Britain, are explained. The manifold local enterprises in central Europe, which happened in the first half of the 19th century, are described in some detail as they prepare the foundation for the following regional project. Simultaneously, Gauss, Bessel and others developed a more sophisticated definition of the Earths figure, which includes the effect of the gravity field. In 1861, the retired Prussian general J.J. Baeyer took up earlier ideas from Schumacher, Gauss, Struve and others, to propose a Central European Arc Measurement in order to study the figure of the Earth in that region. This led to a scientific organization, which soon extended from Central Europe to the whole continent and later to the globe, and changed its name in 1886 to Internationale Erdmessung (International Geodetic Association). The scientific programme also widened remarkably from more local studies based on geometric data to regional and global investigations, with gravity measurements as an important source of information. The Central Bureau of the Internationale Erdmessung was hosted at the Prussian Geodetic Institute in Potsdam, and with Baeyer as Director, developed as an efficient tool of the Association. The scientific research extended and deepened after 1886, when F.R. Helmert became Director of the Central Bureau. A stronger international participation then took place, while the influence of the German states reduced. Of great practical importance were questions of standardization and reference systems, but first attempts to interpret gravity field variations and to monitor geodynamic phenomena by geodetic methods indicated future tendencies. With the First World War and the expiry of the last international convention in 1916, the international cooperation within the frame of the Association practically came to an end, which ended the first epoch of the Association. Nevertheless, due to the strong commitment of two scientists from neutral countries, the International Latitude Service continued to observe polar motion and to deliver the data to the Berlin Central Bureau for evaluation. After the First World War, geodesy became one of the founding members of the International Union for Geodesy and Geophysics (IUGG), and formed one of its Sections (respectively Associations). It has been officially named the International Association of Geodesy (IAG) since 1932.     

GGOS和大地测量技术进展

在2005年8月澳大利亚凯恩斯(Cairns)国际大地测量协会(IAG)科学大会上,全球大地测量观测系统(GlobalGeodeticObservingSystem,简为GGOS)作为这次科学大会一个重要议题成为一个热点问题,也成为未来大地测量学科进展的一个风向标。本文较为全面地介绍了GGOS的背景、目标、任务和科学原理等,结合GGOS在全球动力系统观测中的应用构想,说明了GGOS与其他地球观测系统越来越紧密的联系和相互促进的发展趋势。除此之外,本文还简要介绍了这次科学大会其他领域如大地坐标框架和卫星重力等领域的最新进展。     

The International GNSS Service in a changing landscape of Global Navigation Satellite Systems

The International GNSS Service (IGS) is an international activity involving more than 200 participating organisations in over 80 countries with a track record of one and a half decades of successful operations. The IGS is a service of the International Association of Geodesy (IAG). It primarily supports scientific research based on highly precise and accurate Earth observations using the technologies of Global Navigation Satellite Systems (GNSS), primarily the US Global Positioning System (GPS). The mission of the IGS is “to provide the highest-quality GNSS data and products in support of the terrestrial reference frame, Earth rotation, Earth observation and research, positioning, navigation and timing and other applications that benefit society”. The IGS will continue to support the IAG’s initiative to coordinate cross-technique global geodesy for the next decade, via the development of the Global Geodetic Observing System (GGOS), which focuses on the needs of global geodesy at the mm-level. IGS activities are fundamental to scientific disciplines related to climate, weather, sea level change, and space weather. The IGS also supports many other applications, including precise navigation, machine automation, and surveying and mapping. This article discusses the IGS Strategic Plan and future directions of the globally-coordinated ~400 station IGS network, tracking data and information products, and outlines the scope of a few of its numerous working groups and pilot projects as the world anticipates a truly multi-system GNSS in the coming decade.     

Regional geoid determination in Antarctica utilizing airborne gravity and topography data

Antarctica is the only continent that suffers major gaps in terrestrial gravity data coverage. To overcome this problem and to close these gaps as well as to densify the global satellite gravity field solutions, the International Association of Geodesy (IAG) Commission Project 2.4 “Antarctic Geoid” was set into action. This paper reviews the current situation concerning the gravity field in Antarctica. It is shown that airborne geophysical surveys are the most promising tools to gain new gravity data in Antarctica. In this context, a number of projects to be carried out during the International Polar Year 2007/2008 will contribute to this goal. To demonstrate the feasibility of the regional geoid improvement in Antarctica, we present a case study using gravity and topography data of the southern Prince Charles Mountains, East Antarctica. During the processing, the remove–compute– restore (RCR) technique and least-squares collocation (LSC) were applied. Adding signal parts of up to 6 m to the global gravity field model that was used as a basis, the calculated regional quasigeoid reveals the dominant features of bedrock topography in that region, namely the graben structure of the Lambert glacier system. The accuracy of the improved regional quasigeoid is estimated to be at the level of 15 cm.     

The IAG approach to the atmospheric geoid correction in Stokes' formula and a new strategy

The well-known International Association of Geodesy (IAG) approach to the atmospheric geoid correction in connection with Stokes' integral formula leads to a very significant bias, of the order of 3.2 m, if Stokes' integral is truncated to a limited region around the computation point. The derived truncation error can be used to correct old results. For future applications a new strategy is recommended, where the total atmospheric geoid correction is estimated as the sum of the direct and indirect effects. This strategy implies computational gains as it avoids the correction of direct effect for each gravity observation, and it does not suffer from the truncation bias mentioned above. It can also easily be used to add the atmospheric correction to old geoid estimates, where this correction was omitted. In contrast to the terrain correction, it is shown that the atmospheric geoid correction is mainly of order H of terrain elevation, while the term of order H ² is within a few millimetres. Received: 20 May 1998 / Accepted: 19 April 1999