SC 1.3: Regional Reference Frames

Chair: Fernand Bale (Cote d’Ivoire)

Terms of Reference

Sub-commission 1.3 deals with the definitions and realizations of regional reference frames and their connection to the global International Terrestrial Reference Frame (ITRF) and International Height Reference Frame (IHRF). It offers a home for servicelike activities addressing theoretical and technical key common issues of interest to regional organizations.

Objectives

In addition to the specific objectives of each regional sub-commission, the main objectives of SC1.3 as a whole are to:

  • Coordinate the activities of the regional Sub-commissions focusing on exchange of data, competences and results;
  • Promote operation of permanent GNSS stations, in connection with IGS whenever appropriate, as the basis for the long-term maintenance of regional reference frames;
  • Promote open access to the GNSS data from permanent stations used for the maintenance of regional reference frames and scientific applications;
  • Develop specifications for the definition and realization of regional reference frames, including the vertical component;
  • Encourage and stimulate the development of the AFREF project in close cooperation with IGS and other interested organizations;
  • Encourage and assist countries, within each regional sub-commission, to re-define and modernize their national geodetic systems, compatible with the ITRF;
  • Support the efforts of the United Nations Initiative on Global Geospatial Information Management (UN-GGIM) towards a sustainable Global Geodetic Reference Frame (GGRF).

Program of Activities

  • Provide a forum for addressing activities, results and key issues of common interest to the regional sub-commissions;
  • Develop analysis strategies and compare methods for the implementation of the regional reference frames and their expression in the ITRF, in full interaction with the IGS;
  • Consider developing deformation models that will enable transformation of locations within a defined reference frame between different epochs.

SC 1.3a: Europe (EUREF)

Chair: Martin Lidberg (Sweden)
Secretary: Karin Kollo (Estonia)

Terms of Reference

Sub-commission 1.3a, the regional Reference Frame sub-commission for Europe (EUREF), deals with the definition, realization and maintenance of the European Reference Frames. It is focusing on both the spatial and the vertical components in close cooperation with the pertinent IAG components (Services, Commissions and Inter-commission projects). For more information, see www.euref.eu.

Objectives
  • The definition, realization and maintenance of the European Geodetic Reference Systems;
  • The promotion and assistance of the adoption and use of European Terrestrial Reference System (ETRS89) and European Vertical Reference System (EVRS) in our partner countries;
  • The development and maintenance of the EUREF GNSS Permanent Network (EPN) which is the ground based GNSS infrastructure for scientific and practical applications in positioning and navigation (GGOS, IGS Real-time Service);
  • The development of strategies and technologies for the realization of geodetic reference systems.

SC 1.3b: South and Central America (SIRGAS)

Chair: José Antonio Tarrío (Chile)
Vice-Chair: Demián Gómez (USA)

Terms of Reference

Sub-commission 1.3b (South and Central America) encompasses the activities developed by the “Geocentric Reference System for the Americas” (SIRGAS). As such, it is concerned with defining, realising and maintaining a modern geodetic reference infrastructure for South and Central America and the Caribbean. This includes a geometric reference frame consistent with ITRS/ITRF and a gravity field-related vertical reference system defined and realized globally. For more information, see https://sirgas.ipgh.org.

Objectives
  • To determine, maintain and make available a geocentric reference frame (a set of stations with high-precise geocentric positions and their variation with time) as a regional densification of the global ITRF;
  • To support the SIRGAS countries in establishing and maintening national geodetic reference networks as local densifications of SIRGAS in order to guarantee accessibility to the global ITRF at national and local levels;
  • To establish a unified vertical reference system supporting the determination and precise combination of physical and geometric heights as well as their variations with time;
  • To support the IAG Sub-commission 2.4b (Gravity and Geoid in South America) in activities related to gravity densifications in order to improve the distribution of gravity information and to establish a new Absolute Gravity Network in South America;
  • To contribute to the GGOS program by developing and implementing state-of-the art products based on the SIRGAS observational infrastructure;
  • To promote, support, and coordinate the efforts of the American and Caribbean countries to achieve these objectives.

SC 1.3c: North America (NAREF)

Co-Chairs: Jason Bond (Canada) and Phillip McFarland (USA)

Terms of Reference

Sub-commission 1.3c intends to provide international focus and cooperation for issues involving the horizontal, vertical, and three-dimensional geodetic control networks of North America, including Greenland (Denmark). For more information, see www.naref.org.

Objectives

In collaboration with the IAG community, its Services and the national geodetic organizations of North America, the objectives of Sub-commission 1.3c are:

  • Densification of the ITRF in North America and promotion of its use;
  • Definition, maintenance and future evolution of plate-fixed geometric reference frames for North America, including the North American Datum of 1983 (NAD83) and the forthcoming North American Terrestrial Reference Frame of 2022 (NATRF2022);
  • Effects of crustal motion, including post-glacial rebound and tectonic motions along, e.g., the western coast of North America and in the Caribbean;
  • Coordination of efforts with neighboring SC1.3b South and Central America (SIRGAS) to ensure strong ties between each other’s reference frames;
  • Outreach to the general public through focused symposia, articles, workshops and lectures, and technology transfer to other groups.

SC 1.3d: Africa (AFREF)

Chair: Elifuraha Saria (Tanzania)

Terms of Reference

Sub-commission 1.3d (Africa) is concerned with the definition and realization of a unified continental reference frame (AFREF) for Africa, which will be consistent and homogeneous with the global ITRF.

Objectives

In collaboration with the IAG community and its Services, regional organizations, and the National and Regional Mapping Organizations of Africa, the objectives of Sub-commission 1.3d (Africa) are:

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Program of Activities complete for AFREF!

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Members preliminary

  • Elifuraha Saria (Tanzania); Chair
  • Emanuel Nkurunziza (Kenya)
  • Joseph Dodo (Nigeria)
  • Salah Mahmud (Egypt)
  • Cesare Mbaria (Kenya)
  • Prosper Ulotu (Tanzania)
  • Andre Nonguierma (Burkina Faso)
  • Akingbade O (Nigeria)
  • Moha El-Ayachi (Morocco)
  • Elias Lewi (Ethiopia)
  • Patrick Vorster (South Africa)
  • Kamal Labbassi (Morocco)

Active honorary members

  • Richard Wonnacott (South Africa)
  • Hussein Farah (Kenya)
  • Olajide Kufoniyi (Nigeria)

SC 1.3e: Asia-Pacific (APREF)

Chair: Basara Miyahara (Japan)

Terms of Reference

Sub-commission 1.3e aims to improve regional cooperation that supports the realization and densification of the ITRF. This activity will be carried out in close collaboration with the Geodetic Reference Framework for Sustainable Development Working Group of the United Nations Global Geospatial Information Management for Asia and the Pacific (UN-GGIM-AP). For more unformation, see https://un-ggim-ap.org/wg/working-group-1-geodetic-reference-frame.

Objectives
  • Densification of the ITRF and promotion of its use in the Asia Pacific region;
  • To encourage the sharing of GNSS data from Continuously Operating Reference Stations (CORS) in the region;
  • To develop a better understanding of crustal motion in the region;
  • To promote the collocation of different measurement techniques, such as GNSS, VLBI, SLR, DORIS and tide gauges, and the determination and maintenance of precise local tie vectors among these geodetic techniques at these sites;
  • To provide capacity development opportunities to developing countries through symposia, workshops, seminars, training courses, and technology transfer activities.
Program of Activities

The activities of this Sub-commission will principally be those of the Asia-Pacific Reference Frame (APREF) project. This is a joint project between IAG SC 1.3e and the geodetic working group of UN-GGIM-AP and consists of a Central Bureau, Network operators, Data centers and Analysis centers. The Central Bureau is at Geoscience Australia and functions as the “day-to-day” APREF coordinating body. Specifically, the Central Bureau ensures that APREF products are made available to the global geodetic community.

Furthermore, they are the Combination Centers responsible for analyzing, combining and validating the individual solutions of the contributing Analysis Centers, and for expressing the combined solution in the ITRF.

The resulting APREF data and products have an open access data policy via the internet following the practice of the International GNSS Service (IGS). They consist of daily GNSS RINEX data, station log-files, weekly coordinate estimates in SINEX format, and APREF network and time-series plots. For more details, see https://www.ga.gov.au/scientific-topics/positioning-navigation/geodesy/asia-pacific-reference-frame.

Members

The members of the SC 1.3e are national geodetic representatives from the UN-GGIMAP member nations and APREF participating organizations.

1. UN-GGIM-AP WG1 (Geodetic Reference Frame)

  • Basara Miyahara (Japan); Chair
  • Guorong Hu (Australia); Vice-Chair
  • Yamin Dang (China)
  • Asakaia Tabua (Fiji)
  • Upendra Nath Mishra (India)
  • Sidik Tri Wibowo (Indonesia)
  • Seyed Abdoreza Saadat Mirghadim (Iran)
  • Ahmad Sanusi bin Che Cob (Malaysia)
  • Dalkhaa Munkhtsetseg (Mongolia)
  • Nic Donnelly (New Zealand)
  • Jongsin Lee (South Korea)

2. APREF Analysis Group

  • Guorong Hu (Australia)
  • Alex Woods (Australia)
  • Yunbin Yuan (China)
  • Basara Miyahara (Japan)

SC 1.3f: Antarctica

Chair: Martin Horwath (Germany)

Terms of Reference

Sub-commission 1.3f focuses on the realization and densification of a unified reference frame for Antarctica, which will be consistent with the global ITRF. The Sub-commission shares objectives and activities of the Scientific Committee on Antarctic Research (SCAR), namely of the SCAR Expert Group Geodetic Infrastructure of Antarctica (GIANT). The Sub-commission closely links IAG and SCAR activities by embedding identical activities (with identical persons where indicated) into the two complementary organizational structures.

Objectives
  • Maintenance and densification of the precise geodetic reference network in Antarctica by permanent observations and GNSS campaigns;
  • Realization of a unified vertical datum including GNSS ties of tide gauges;
  • Providing unified reference for further GNSS applications like airborne gravimetry, ground truthing for satellite missions, geodynamics and glaciology;
  • Develop technologies for remote geodetic observatories;
  • Stimulate and coordinate international collaboration on the above fields, under the unique political conditions of Antarctic research given by the Antarctic Treaty, in order to make optimum use of logistics and infrastructure.
Program of Activities
  • Organization of GNSS campaigns in Antarctica;
  • Extend activities for the operation of remote permanent GNSS stations;
  • Maintenance of the data archive (SCAR GNSS data base) to collect Antarctic GNSS data and provide them to the scientific community;
  • Data analysis and determination of the Antarctic GNSS network as a regional densification of ITRF;
  • Provide homogeneous site velocities for e.g. glacial iso-static adjustment determination;
  • Support airborne surveys and satellite missions with precise terrestrial reference;
  • Collaborate with IAG Sub-Commission 3.4 (Cryospheric Deformation) and the SCAR Scientific Research Programme Solid Earth Response and Influence on Cryosphere Evolution (SERCE) and subsequent programmes, respectively;
  • Organize special workshops on the consistent analysis of GNSS data and realization of ITRF;
  • Organize meetings/sessions at conferences like IAG, IUGG, SCAR Open Science Conference.
Members
  • Martin Horwath, (Germany); Chair
  • Yuichi Aoyama (Japan)
  • Manuel Berrocoso (Spain)
  • Alessandro Capra (Italy)
  • Dave Collett (New Zealand)
  • Rene Forsberg (Denmark)
  • Thomas James (Canada)
  • Aspurah Kamburov (Bulgaria)
  • Hannu Koivula (Finland)
  • Matt King (Australia)
  • Kenichi Matsuoka (Norway)
  • Alexey Matveev (Russia)
  • Gennadi Milinevsky (Ukraine)
  • Elizabeth Petrie (United Kingdom)
  • Goncalo Prates (Portugal)
  • Mirko Scheinert (Germany)
  • Norbertino Suarez (Uruguay)
  • Terry Wilson (USA)
  • Andres Zakrajsek (Argentina)