The recently reorganized GGOS Bureau of Networks and Observations has many elements that are associated with building and sustaining the infrastructure that supports the Global Geodetic Observing System (GGOS) through the development and maintenance of the International Terrestrial and Celestial Reference Frames, improved gravity field models and their incorporation into the reference frame, the production of precision orbits for missions of interest to GGOS, and many other applications. The affiliated Service Networks (IVS, ILRS, IGS, IDS, and now the IGFS and the PSMSL) continue to grow geographically and to improve core and co-location site performance with newer technologies. Efforts are underway to expand GGOS participation and outreach. Several groups are undertaking initiatives and seeking partnerships to update existing sites and expand the networks in geographic areas void of coverage. New satellites are being launched by the Space Agencies in disciplines relevant to GGOS. Working groups now constitute an integral part of the Bureau, providing key service to GGOS. Their activities include: projecting future network capability and examining trade-off options for station deployment and technology upgrades, developing metadata collection and online availability strategies; improving coordination and information exchange with the missions for better ground-based network response and space-segment adequacy for the realization of GGOS goals; and standardizing site-tie measurement, archiving, and analysis procedures. This poster will present the progress in the Bureau's activities and its efforts to expand the networks and make them more effective in supporting GGOS.

The International GNSS Service (IGS), formerly the International GPS Service, is a voluntary federation of more than 200 worldwide agencies that pool resources and permanent GPS & GLONASS station data to generate precise GPS & GLONASS products. The IGS is committed to providing the highest quality data and products as the standard for Global Navigation Satellite Systems (GNSS) in support of Earth science research, multidisciplinary applications, and education. Currently the IGS includes two GNSSs: GPS and the Russian GLONASS. In view of the ongoing GPS modernisation and the buildup of new navigation systems such as BeiDou, Galileo and QZSS, the IGS has recently established the Multi-GNSS Experiment (MGEX). MGEX serves as a platform for early experimentation and familiarisation with the emerging new signals and constellations. Aside from collecting multi-GNSS tracking data from a global network implemented in parallel to the core IGS network, MGEX promotes the generation of dedicated multi-GNSS orbit and clock products and the development of advanced processing algorithms. The paper describes the current status of the MGEX project, discusses early achievements and presents the long-term vision for transitioning the IGS into a fully generic multi-GNSS service.

Within the International GNSS Service (IGS), more than 200 worldwide agencies have, for many years, pooled resources and permanent GNSS station data to generate precise GNSS products in support of Earth science research, multidisciplinary applications, and education. So far, this service has been restricted to two systems — namely, GPS and GLONASS. In recognition of the rapidly evolving GNSS landscape, the IGS has set up the Multi-GNSS Experiment (MGEX) to explore and promote the use of new navigation signals and constellations. It will enable an early familiarization with new GNSS, identify and overcome relevant challenges, and prepare use of emerging navigation systems in routine IGS products. MGEX comprises the build-up of a new network of sensor stations, the characterization of the user equipment and space segment, the development of new concepts and data processing tools, and the generation of early data products for Galileo, QZSS, and BeiDou. MGEX is coordinated by the IGS Multi-GNSS Working Group (MGWG), which interacts closely with other IGS entities, such as the RINEX WG, the Antenna WG, the Data Center WG, and the Infra-structure Committee. The article starts out with a description of the MGEX network that formed the starting point and initial focus of the overall MGEX project. Following a description of system characterization activities, the current status of multi-GNSS data products and ongoing efforts for the development of new standards for multi-GNSS-related work within the IGS are presented.

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.

This slide presentation reviews the development and deployment of the Global Positioning System (GPS). This presentation also includes measuring space and time, GPS as a tool for science, development of high precision JPL GPS receivers, and technology and applications developments.

The International GNSS Service (IGS) is an international activity with more than 200 participating organisations in over 80 countries with a track record of more than 13 years of successful service. The IGS is a service of the International Association of Geodesy (IAG) and primarily supports the scientific research based on, and the analysis of, long-term, highly precise and accurate Earth observations using the technologies of Global Navigation Satellite Systems (GNSS), primarily the U.S. Global Positioning System (GPS). The mission of the IGS, recently revised at the IGS Strategic Planning Meeting held in December 2006, 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. The IGS activities are fundamental to scientific disciplines related to climate, weather, sea level change, and space weather. However, the IGS also supports many other applications, including precise navigation, machine automation, and surveying and mapping. This paper will discuss the IGS Strategic Plan and future directions of the globally-coordinated ~400 station IGS network, tracking data and information products, and outline the concerns of a few of its numerous working groups and pilot projects as the world anticipates a truly multi-system GNSS in the coming decade.

The paper reviews some objectives and preparatory activities of the International GNSS Service (IGS), in relation to the developing European Global Navigation Satellite System Galileo. Experience already acquired in the IGS in monitoring multiple global navigation satellite systems (GPS and GLONASS) is reviewed. Some significant features of the Galileo system are outlined, including constellation design, and some areas are identified in which Galileo will influence IGS operations in the future and in which the IGS and its active elements can continue to contribute to new GNSS developments. These include the IGS GNSS Working Group, the Galileo System Test Bed GSTB-V2 and the Galileo Geodetic Service Provider (GGSP) Prototype.

Properly designed and structured ground-based geodetic networks materialize the reference systems to support sub-mm global change measurements over space, time and evolving technologies. Over this past year, the Ground Networks and Communications Working Group (GN&C WG) has been organized under the Global Geodetic Observing System (GGOS) to work with the IAG measurement services (the IGS, ILRS, IVS, IDS and IGFS) to develop a strategy for building, integrating, and maintaining the fundamental network of instruments and supporting infrastructure in a sustainable way to satisfy the long-term (10-20 year) requirements identified by the GGOS Science Council.Activities of this Working Group include the investigation of the status quo and the development of a plan for full network integration to support improvements in terrestrial reference frame establishment and maintenance, Earth orientation and gravity field monitoring, precision orbit determination, and other geodetic and gravimetric applications required for the long-term observation of global change. This integration process includes the development of a network of fundamental stations with as many co-located techniques as possible, with precisely determined intersystem vectors. This network would exploit the strengths of each technique and minimize the weaknesses where possible.

Des reseaux geodesiques terrestres bien concus et structures permettent de materialiser les systemes de reference afin de prendre en compte les changements mondiaux dans l'espace, le temps et les nouvelles technologies a un niveau inframillimetrique. Le groupe de travail sur les communications et les reseaux terrestres (Ground Networks and Communications Working Group (GN&C WG)) du Systeme global d'observation geodesique (GGOS) de l'Association internationale de geodesie (AIG) a travaille avec les services de prises de mesures de l'AIG (l'IGS, l'ILRS, le SIR, l'IDS et l'IGFS) afin d'elaborer une strategie pour edifier, integrer et maintenir le reseau essentiel d'instruments et d'infrastructures de facon durable afin de repondre aux besoins a long terme (10 a 20 ans) cernes par le Conseil des sciences du GGOS. Le Groupe de travail se prete notamment a l'evaluation du statu quo et a l'elaboration d'un plan pour l'integration complete du reseau afin de comprendre les ameliorations a l'elaboration et au maintien du cadre de reference terrestre, la surveillance de l'orientation et du champ gravitationnel terrestres, la determination precise de l'orbite et d'autres applications geodesiques et gravimetrique necessaires a l'observation des changements mondiaux a long terme. Ce processus d'integration comprend l'elaboration d'un reseau de stations principales integrant autant de techniques conjointes que possible et de vecteurs, determines avec precision, entre les systemes. Ce reseau exploiterait les forces de chacune des techniques et minimiserait leurs faiblesses. Cet article presente l'organisation du groupe de travail, le travail accompli a ce jour ainsi que ses prochaines tâches.