Global Navigation Satellite Systems (ICG)

Global Navigation Satellite Systems (ICG)

efficiency and safety of transport, search and rescue, geodesy, land management and sustainable development. The ICG addressed applications to promote...

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efficiency and safety of transport, search and rescue, geodesy, land management and sustainable development. The ICG addressed applications to promote the enhancement of universal access to, and compatibility and the inter-operability of space-based navigation and positioning systems, and the integration of those services into national and regional infrastructures, particularly in developing countries. The ICG adopted terms of reference and a work plan as developed in international meetings held since 2002. The current work plan include matters pertaining to compatibility and inter-operability; enhancement of performance of GNSS services; information dissemination; interaction with national and regional authorities and relevant international organizations; and coordination. All participants would cooperate, as appropriate, on matters of mutual interest related to civil satellite-based positioning, navigation, timing and valueadded services. In particular, they would cooperate to the maximum extent practicable to maintain radio frequency compatibility in spectrum use between different GNSS systems in accordance with the ITU Radio Regulations. A Providers Forum was established in 2007 at the second meeting of the ICG in Bangalore, India, with the aim of promoting greater compatibility and inter-operability among current and future providers of the Global Navigation Satellite Systems (GNSS). The current members of the Forum, including China, India, Japan, the European Community, the Russian Federation and the USA, have already addressed key issues such as ensuring protection for the GNSS spectrum and matters related to orbital debris/orbit de-confliction. As recommended by the ICG and the Providers Forum, a one-day ICG Expert Meeting on Global Navigation Satellite Systems and Services was held on 15 July 2008, for the first time introducing the scope and work of the ICG to the international community. The focus of the meeting was on

It has been recommended that the UNCOPUOS Scientific and Technical Subcommittee should include the ‘International Space Weather Initiative’ as a new item to be organized along the following lines in the coming years: 2009: Contact initiatives relevant to the ISWI, with respect to science and applications aspects; initial meeting (s) of the ISWI planning committees; develop overall strategy, outreach strategy and regional plans; synthesis from regional to international plans, merging of science working groups and campaigns; backfill missing initiatives; foster the continued operation of existing instrument arrays, and encourage new instrument deployments; emphasize requirements for data analysis and access to real-time data – these latter activities would continue 2010 through to 2012 (and possibly beyond). 2010: Official start of the ISWI as a UN programme; plan and organize first UNBSS/ ISWI workshop; Consider reports on regional and international plans. 2011: Identify gaps and synergies in ongoing activities. 2012: Finalize a report on regional and international activities relevant to the ISWI and submit report on the ISWI accomplishments and activities to UN OOSA.

Global Navigation Systems (ICG)

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he International Committee on Global Navigation Satellite Systems (ICG) was established in 2005 and held its first meeting in Vienna on 1-2 November 2006 to review and discuss matters relating to Global Navigation Satellite Systems (GNSS) and their applications. Those applications include safety and economic development, particularly the

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demia, and governments shared views on GNSS compatibility and inter-operability. The following countries or regions had representatives at the meeting, which was hosted by the USA: China, the European Community, India, Japan, the Russian Federation, the USA, Italy, Malaysia, Nigeria, the United Arab Emirates, and the following international organizations were also represented : the Bureau international des poids et mesures (BIPM), COSPAR, the Civil GPS Service Interface Committee (CGSIC), the European Position Determination System (EUPOS), the Fédération internationale des géomètres (FIG), the International Association of Geodesy (IAG), the International Association of Institutes of Navigation (IAIN), the International GNSS Service (IGS, formerly International GPS Service), and the UN Office for Outer Space Affairs. The Canadian Space Agency (CSA) and the UN-affiliated Regional Centre for Space Science and Technology Education for Latin America and the Caribbean attended as invited observers. The IAG Reference Frame Sub-Commission for Europe (EUREF) also attended and was recognized by the International Committee as a new associate member. The International Committee recalled that in its resolution 62/217 of 21 December 2007, the UN General Assembly noted with appreciation that the International Committee on Global Navigation Satellite Systems was established on a voluntary basis as an informal body to promote cooperation, as appropriate, on matters of mutual interest related to civil satellite-based positioning, navigation, timing and value-added services, as well as the compatibility and inter-operability of global navigation satellite systems, while increasing their use to support sustainable development, particularly in developing countries. The International Committee noted that working groups were focused on compatibility and inter-operability; enhancement of performance of GNSS services;

identifying the needs of users and manufacturers of user equipment with respect to the compatibility and inter-operability of global systems, regional systems and space-based augmentations providing, or planning to provide, GNSS services. This Meeting reached out to the international community in its endeavour to convey information as to the objectives of the Providers Forum, the ongoing efforts of ICG Working Groups, and the benefits of interaction between GNSS providers and users. The President of COSPAR contributed to the opening of the Meeting. The sessions of the meeting focused on (a) the ICG work plan and working group overviews: co-chairs of each working group gave descriptions of the actions underway to accomplish the work plan of the ICG with a focus on activities since the second meeting of the ICG, in Bangalore in September 2007; (b) an overview of the GNSS: all system and augmentation system providers presented reports on the technical characteristics of their particular systems and services provided to GNSS users; (c) compatibility and interoperability at the user equipment level: leaders from industry, academia, and organizations representing users or producers provided information on their specific application sectors emphasizing the compatibility and inter-operability of the various satellite systems from their own perspectives; (d) a panel of providers and users/producers on the importance of compatibility and interoperability among satellite systems. The ICG met again in Pasadena, California, from 8 to 12 December 2008, to undertake a further review and discussion of developments in global navigation satellite systems and to consider matters of interest to ICG by its members, associate members and observers. The International Committee also addressed global navigation satellite systems (GNSS) science and innovative technology applications and future commercial applications. Representatives from industry, aca-

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paradigm[1], we live in space-time, a 4dimension manifold, and free particles follow geodesics in it. Gravity curves the geometry of this manifold. Thus, geodesics followed by free test particles are no longer straight lines, as they would be instead in the absence of gravity. A straight line in space-time represents motion without any acceleration, i.e., certainly a straight trajectory in space, but with the additional prescription that the particle moves at constant velocity. Thus the primary manifestation of gravity is the relative acceleration of free-falling particles. Within the metric paradigm, different theories are possible[1] , differing from each other by the prescription according to which gravity distorts the geometry of space-time. Over the years, Einstein’s General Relativity has been bravely and overwhelmingly resisting the attacks of competing theories, its agreement with measurements being unchallenged to date. The metric paradigm and, in particular, General Relativity is still full of unexploited promises. Probably the most important one is the opening of the crucial gravitational sector in the observation of the universe, via the detection of gravitational radiation emitted by celestial bodies. However, it is also a strong constraint to our understanding of the way gravity can be merged with the remaining fundamental interactions, and in particular on how gravity behaves in the quantum realm. Space-borne experiments have played and are playing a strong role in the study of this subject, thanks to two main features that can only be achieved in space. The large size of the experiment, a straight multiplying factor for many experimental effects, and the increasingly high accuracy level of the free fall of test particles that can be achieved in these experiments. This paper gives a short overview of more than 50 years of missions and studies, that started shortly after COSPAR was founded, with lunar laser ranging, and extends

information dissemination and capacity building; and interaction with national and regional authorities as well as relevant international organizations. It was recognized that substantive progress in furthering the ICG Workplan, approved at the first meeting of the ICG in Vienna in 2006, had been made. The International Committee noted that the Providers Forum had adopted Terms of Reference and a Workplan. The Plenary of the ICG also affirmed that the Regional Centres for Space Science and Technology Education, affiliated to the United Nations, would act as ICG Information Centres. The International Committee further agreed to establish Task Forces on Geodetic References and on Time References in order to promote progress in its Workplan. The International Committee accepted the invitation of the Russian Federation to host the fourth meeting, to be held in St Petersburg, from 14 to 18 September 2009. The Committee also noted the offer of the European Community and Italy to jointly host the succeeding meeting in 2010. The UN Office for Outer Space Affairs, as the Executive Secretariat of the ICG and the Providers Forum, undertook to assist in the preparations for these meetings and interim planning and working group activities.

Research Highlights Space and the Spacecraft as a Precision Laboratory [By Stefano Vitale, Dept. of Physics, University of Trento and INFN, Italy] [Presented as a COSPAR 50th Anniverary Lecture in Montréal, July 2008]

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he metric paradigm is at the basis of our best understanding to date of space, time and gravity. According to this

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