Message-Id: Date: Thu, 9 Nov 2000 17:09:18 -0800 To: afref@igscb.jpl.nasa.gov From: "Ruth E. Neilan" Subject: [AFREF-1] AFREF Minutes, 27 April 2000 Meeting, Nice Sender: owner-afref Precedence: bulk ****************************************************************************** AFREF Mail 09 Nov 17:06:49 PST 2000 Message Number 1 ****************************************************************************** Author: Ruth Neilan Final Minutes Organizational Meeting African Reference System "AFREF" April 27, 2000 Centre Universitaire Mediterranean (CUM) Nice, France These minutes have been updated and corrected as of July 31, 2000. The Executive summary is followed by a list of attendees and then by more detailed minutes of the discussions. At the end you will find a list of web resources which may be useful to this project. Meeting Objective Discuss possible organization of a project to establish a common geodetic reference system throughout Africa compatible with the International Terrestrial Reference System (ITRF). Discuss ways to involve the international geodesy community to work with African nations to develop a single, uniform, continental geodetic reference system meeting international standards to replace the myriad national reference systems, many of which have not been maintained, and are out of date and inaccurate. Meeting Organization Called by Claude Boucher, head of Commission X of the International Association of Geodesy (IAG) "Global and Regional Networks", also head of the ITRF and the representative of the International Earth Rotation Service (IERS) to the International GPS Service (IGS). The IGS is active globally in supporting the mission of the IAG & IERS/ITRF through the techniques and applications of the Global Positioning System (GPS). GPS is the most economical and widely accessible modern geodetic technology for realizing a continental reference network throughout Africa. Executive Summary The decision was taken at this preliminary meeting to pursue the coordination of a project designated "AFREF", the objective of which is to establish a continental, robust and homogenous geodetic reference system throughout Africa. Africa remains the only continent with paucity of satellite geodetic measurements, especially GPS observations, either episodic, or continuous. There are a few notable exceptions: locations in South Africa, single stations in Malindi, Kenya; Mas Palomas, Canary Islands, Spain; Libreville, Gabon and at previous times a station each in Ghana and Cote 'd Ivoire. Difficulties of in-country support, communications, reliable infrastructure and lack of resources hinder permanent, high quality GPS station implementations at Helwan, Egypt; Adis Ababa, Ethiopia; Rabat, Morocco; and Kampala, Uganda, for example, where equipment have been installed. This meeting and earlier ad-hoc discussions have highlighted the importance of a renewed effort to realize a reference system for this continent through international collaboration directly with the African nations. It was emphasized that this must truly be a joint effort with Africans to be successful and that it must focus on the transfer of appropriate technology to sustain the references with modern instrumentation, e.g. GPS and other satellite techniques. It is also noted that resources will be required to enable organizational participation and project activities (e.g. travel, equipment, technical support, etc.) The meeting attendees agreed to further explore and pursue a joint project 'AFREF' with the Africans and other international partners, and that such a project should: 1. Support and ensure the fundamental basis for the national 3-d reference networks for today and in the future through a continental African geodetic network fully consistent and homogeneous with the global reference frame of the ITRF. 2. Establish continuous, permanent GPS stations such that each nation or each user has free access (and at least within 1000km) of such stations. 3. Provide a sustainable development environment for technology transfer, so that these activities will enhance the national networks and numerous applications with readily available technology 4. Understand the necessary geodetic requirements of participating national and international agencies. 5. Assist in establishing in-country expertise for implementation, operations, processing and analyses of modern geodetic techniques, primarily GPS. Summary Actions: 1. Prepare a letter from the IAG to various African and international contacts to assess interest in a geodetic reference system project; assess if people would be willing to send someone to an exploratory meeting in Africa at location(s) to be determined prior to mailing the letters (current proposed locations: Capetown, Egypt, Addis Ababa'....) 2. Boucher to prepare draft letter, meeting location should be discussed and decided, one can be conducted in conjunction with CONSAS 2001 in Capetown, March 2001 3. Compile a list of African contacts and a list of potential international collaborators for such a project. 4. Use IAG,IGS, Africover lists, and local contacts to provide additional contact information, e.g., from Wonnacott for southern African regions; Chodota, Reilinger, Billham, etc. for other areas 5. In parallel, investigate potential resources and funding to support the activities of both the project planning, travel for participants, as well as project execution. 6. Based on the above actions and results, organize meeting(s) in Africa to support project organization Attendance: o Luca Alinovi, Chief Technical Adviser, United Nations Food and Agriculture Organization, AFRICOVER - Eastern Africa (Nairobi, Kenya) luca.alinovi@africover.org o Dr. Matthias Becker, Analysis Coordinator for EUREF, Bundesamt fuer Kartographie und Geodaesie (Frankfurt, Germany) becker@ifag.de o Dr. Claude Boucher, President, Commission X, Global and Regional Geodetic Networks within the International Association of Geodesy (IAG) (Paris, France) cboucher@club-internet.fr o Dr. Denizar Blitzkow, Chair of IAG Committee on Developing Countries (Sao Paulo,Brazil) dblitzko@usp.br o Dr. Werner Gurtner, Chair of Technical Working Group EUREF, University of Bern (Bern, Switzerland) gurtner@aiub.unibe.ch o Oddgeir Kristiansen, Statens Kartverk, Geodetic Institute, Norwegian Mapping Authority (Honefoss, Norway) oddgeir.kristiansen@statkart.no o John Latham, Remote Sensing Officer (Agriculture), United Nations Food and Agriculture Organization, Environmental Information Management Service (Rome, Italy) John.Latham@fao.org o José Nuno dos Reis Pedroso de Lima, Instituto de Investigacao Cientifica Tropical Centro de Geodesia (Lisbon, Portugal) jnunolima@mail.telepac.pt o Ruth Neilan, Director, Central Bureau of the International GPS Service (Pasadena, CA, U.S.A.) ruth.neilan@jpl.nasa.gov o Dr. Wolfgang Schlueter, Manager, Fundamental Station Wettzell, Bundesamt fuer Kartographie und Geodaesie (Frankfurt, Germany) schlueter@wettzell.ifag.de o Jim Slater, National Imagery and Mapping Agency (Washington, DC, USA) slaterj@nima.mil Meeting invitees, unable to attend: o Dr. Francois Barlier, Grasse, Francbarlier@obs-azur.fr o Jean-Philippe Dufour, Ecole Nationale des Sciences Geographiques jean-philippe.dufour@diplomatie.fr o Herve Fagard, Institut Geographique National (Paris, France) herve.fagard@ign.fr, o Dr. Erich Gubler, Bundesamt fuer Landestopographie, (Bern, Switzerland) erich.gubler@lt.admin.ch o Bjorn Geiir Harsson, Statens Kartverk, Geodetic Institute, Norwegian Mapping Authority (Honefoss, Norway) bjorn.geirr.harsson@statkart.no, o Dr. Muni Kumar, National Imagery and Mapping Agency (Washington, DC, USA) kumarm@nima.mil, o Prof. Christoph Reigber, Chair IGS Governing Board, GeoForschungsZentrum, (Potsdam, Germany) reigber@gfz-potsdam.de o Dr. Joao Manuel Torres, Instituto Portugues de Cartografia e Cadastro, Lisboa, Portugal jatorres@ipcc.pt o Prof. Carl Christian Tscherning, IAG Secretary General, University of Copenhagen, (Copenhagen, Denark) cct@osiris.gfy.ku.dk, o Richard Wonnacott, Director Survey Services, Chief Directorate Surveys and Mapping, South Africa, (Capetown, South Africa) rwonnacott@sli.wcape.gov.za Detailed Minutes April 27 NICE, FRANCE The meeting began with a round table introduction of each attendee who described work they were involved with related to the organization of an African reference system project. Claude Boucher summarized the African Doppler positioning campaign, 'ADOS' which took place in the 1980s that established geodetic control points throughout Africa based on the TRANSIT navigation satellite system. The ADOS project was a major effort organized by IAG with help from other organizations. Many of these control points have been lost or destroyed during the intervening years and are no longer reliable or retrievable in many cases. John Latham, from the Environmental and Natural Resources of Food and Agricultural Organization (FAO) of the United Nations described the goals of the AFRICOVER project that was built from the country-level up beginning in 1994 and used working groups in each country to develop the project. The AFRICOVER project goal is to realize a continental, georeferenced data base for landcover to be used for resource management, environmental management, disaster planning and relief. They are interested in strengthening institutional connections between agriculture agencies and national mapping agencies. One of the objectives is to standardize data and products in all these countries. All the work they are doing uses WGS 84 as the reference system. The FAO has generated a report that describes cartographic and geodetic capabilities in each African country which was circulated at the meeting. They are purchasing Landsat imagery and some Russian imagery in support of their work. The regional part of this project covering Central Africa is sponsored by the World Bank and European banks at the $30+ million level. It was noted that sharing data among some countries in Africa was a problem. The average cost of meetings that were held in Africa has been about $15,000 for a 3-5 day meeting of ~30 participants from 10 countries and where the FAO has paid all expenses of participants. Luca Alinovi, from FAO is the Program Manager of an AFRICOVER region 10 countries from eastern Africa, Egypt to Tanzania and from Uganda to N.E. Africa, including the riparian Nile, Burundi and Sudan. He described the activities of AFRICOVER within this region and the importance of the geodetic basis. Jim Slater, National Imagery and Mapping Agency reviewed the organizational aspects and issues associated with the South American geodetic reference system project that Dr. Kumar and he helped to organize a few years ago. That project was very successful and continues to this date. It resulted in a new geocentric, continental reference frame for South America that was adopted by every country in South America. This "SIRGAS" reference frame is compatible with WGS 84. Slater made the following points based on experience with the SIRGAS project: o all meetings were held in South America o each country had a representative to the project committee chaired by a Brazilian, Luis-P. Fortes o collaborating international groups acted mostly as consultants and helped to provide equipment o processing of the data was done by a German group in Munich at DGFI and NIMA, and processing and analysis the capabilities are improving within South America o The first campaign was in 1995 totaling ~70 stations in the 9 countries as a simultaneous GPS campaign; countries were limited to ~5 stations tied directly to the ITRF. The key difficulties were mostly economic, and travel funding was a big issue. IAG provided limited funds. He noted that there was a high level of interest and participation with the resulting network defined at ~5cm level or better. Slater also said that there is a GPS receiver established at the US Embassy in South Africa. Ruth Neilan, International GPS Service, described IGS activities throughout Africa and the difficulty of establishing permanent long term stations there due to lack of infrastructure. IGS has been successful in a few locations, but the network is still too sparse even from the global perspective. She reported on recent meetings in South Africa with South African colleagues Richard Wonnacott (SA Surveys and Mapping), Prof. Charles Merry (University of Capetown) and Ludwig Combrinck (Harteebeesthoek Radio Astronomy Observatory) concerning AFREF. There was a consensus that such a project was very worthwhile and they would be willing to help IAG/IGS organize as necessary. A meeting is proposed for March 2001 in conjunction with the CONSAS (Congress of South African Surveyors) which will be heavily attended by South Africans as well as a neighboring countries. IGS plans a tutorial during this venue which guides people on how to use IGS data and products. IGS stations are currently operating in Maspalomas, 3 in South Africa, Malindi, Seychelles and Libreville. Stations that have operated in the recent past and may be expected to do so in the future include locations in Ivory Coast, Ghana, Egypt, and Morocco. A new station is being implemented in Uganda. Jose Nuno de Lima, from the Tropical Research Sciences Institute in Lisbon Portugal noted his organization's geodetic survey activities: o recently established in Angola ~3000 GPS points at 1st order, o 1999 surveys in Cape Verde Island resulted in ~20 GPS points tied to IGS, o planning of a campaign in Mozambique with ~700 GPS points. Werner Gurtner briefly described the cooperative nature of the European Reference System (EUREF) which has about 80-90 permanent tracking stations and 10 analysis centers processing data from these stations. He pointed out that the reference system for Africa may be accomplished in more of a patchwork manner as it may be difficult to make all observations simultaneously, however, the strength of the IGS is that sequential GPS observations can be incorporated with no loss of precision. IGS currently achieves the following rms station solutions: 3-5 mm horizontal, 8-10 mm vertical. Map accuracy requirements are generally in the decimeter to meter level; a continental geodetic reference system will need to be at the sub-decimeter level (3-d) to support geodetic applications, especially those involving GPS measurements. Latham wondered about the utility of 2-5 cm versus 50 cm. There was further discussion on the conventional campaign approach for episodic measurements and the newer point positioning technique, with cost/benefit considerations noted. During the discussion that followed, a number of points were made that generally everyone agreed with. Future meetings must be held in Africa and a source of travel funds must be found to enable the representatives of participating African nations to travel to the meetings. A patchwork approach to an African reference system may be the only workable scheme - in effect, a regional approach but tied to the ITRF. Training, equipment and computational support would most likely have to be provided by the external organizations willing to act as consultants for this project, since many of the African countries do not have the required GPS equipment, software and expertise. A major issue will be whether the countries will be able to maintain the network of reference stations after they are installed. The FAO representatives suggested using airports as reference stations since these are better protected and can offer better infrastructures as well as support the International Civil Aviation Organization's requirements for conversion to WGS 84. Neilan noted that there are existing GPS and IGS stations located at airports for these very reasons. There was considerable discussion on how to integrate the African continent into the international scientific enterprise while at the same time meeting the practical needs of the African nations. There was agreement that establishing a few geodetic reference stations in each country could be a first goal. One or more of these stations may become a candidate for a continuous tracking station that could then be incorporated into the permanent IGS network. Reference websites: IAG: http://www.gfy.ku.dk/~iag/ IGS: http://igscb.jpl.nasa.gov ITRF: http://lareg.ensg.ign.fr/ITRF/ NIMA: 164.214.2.59/GandG/GandG.html FAO: http://www.fao.org/ FAO/Sustainable Development Dept.: http://www.fao.org/WAICENT/FAOINFO/SUSTDEV/Welcome_.htm EUREF: http://homepage.oma.be/euref/ SIRGAS: http://www.dgfi.badw-muenchen.de/gps/sirgas.html minutes respectfully submitted by: Ruth Neilan, Central Bureau of the International GPS Service acknowledging contributions from Jim Slater Corrected minutes, 31 July 2000 ============================================================================ Ruth E. Neilan Telephone: (818)-354-8330 Director, IGS Central Bureau FAX: (818)-393-6686 Jet Propulsion Laboratory E-mail (IGS): igscb@igscb.jpl.nasa.gov MS 238-540 E-mail: ruth.neilan@jpl.nasa.gov 4800 Oak Grove Drive Pasadena, CA 91109 IGS CBIS: http://igscb.jpl.nasa.gov/ Secretary: Mary Ann Hall, tel: 818-354-2077, Mary Ann.C.Hall@jpl.nasa.gov ============================================================================