The IGS Network in Africa; an update and real-time issues.
Ludwig Combrinck
Hartebeesthoek
Radio Astronomy Observatory, South Africa
The IGS network stations in Africa have increased slowly in number during the last five years, with the equatorial and southern part of Africa being the most densely populated at this time. Several additional stations will be installed by HartRAO in the near future, in collaboration with international partners. These IGS stations will form important nodes of the southern component of the African Reference Frame. HartRAO is initially targeting the 14 Southern African Development Community (SADC) countries as possible hosts for new stations. The aim is to develop the SADC GPS Network as an official SADC project. Internet connectivity has improved during the last five years, but for most African countries, Internet service providers (ISPs) are still only available in major cities. There is a trend in space geodesy to move towards real-time, which will require reliable Internet connections as well as great bandwidth for some applications such as VLBI, where a data rate of 1 Gbs is a minimum requirement for a given station. Will Africa be able to participate in real-time space geodesy?
Poor distribution and irregular electricity networks in many African countries adversely affect the availability of Internet in rural areas, therefore ISPs are mostly established in major cities. Even so, the Internet is expanding rapidly, with many countries adopting local call charges for all calls accessing the Internet regardless of the distance involved.
Most African capitals have more than one ISP; South Africa, Egypt, Morocco, Kenya, Nigeria, Tanzania and Togo have 10 or more. Countries with better developed infrastructures such as South Africa and the highly developed North Africa countries have more ISPs and they are also more widely distributed. Public telecom operators have established Internet services in 33 countries and although these usually provided the only international link, many now face competition with private sector international links via VSAT. Currently, lack of circuit capacity and high international tariffs suppresses access to sufficient international bandwidth that would be necessary for real-time GPS networks.
The importance of addressing information and communication technologies is recognised by local and international role players. It is expected that additional resources will be channeled to the development and support of the Internet in Africa, although certain governments need to speed up and transform their methods of restructuring their communication infrastructure. Competition is an essential element in the dynamical and constantly changing world of communications technologies. Monopoly ISPs supported by national policy (Ethiopia, Mauritius and some countries in the Sahel sub-region) should be viewed as adequate only for an initial introduction into the Internet, but should not be a long-term policy. There are currently a large number of information and communication development projects in Africa. Although real-time space geodesy is feasible from a limited number of countries at present, the future seems bright and the global geodetic community can expect Africa to participate.
The SADC consists of 14 member states; Angola, Botswana, D.R.C., Lesotho, Malawi, Mauritius, Mozambique, Namibia, South Africa, Seychelles, Swaziland, Tanzania, Zambia and Zimbabwe. Of these, only South Africa, Seychelles and Zambia (very recently) have permanent GPS receivers. HartRAO is planning to install IGS stations in Namibia and Malawi in the near future. It is planned to equip all SADC member states with an IGS station within the next 2 years.
The ultimate objective of SADC is to achieve an improvement in the living standards of the people of the Region. This can be achieved through development and economic growth, self-sustaining development and complementary national and regional programmes. Developing a SADC regional GPS network (Combrinck 1998) as a southern component of the African Reference Frame (Neilan and Wonnacott 2002), will aid in achieving this objective through providing modernization of local mapping agencies' national reference systems and surveying capabilities. A multitude of applications will benefit directly, amongst which are GIS, land distribution and management, mapping, civil engineering and scientific or research applications of GPS.
Africa has a bright future ahead, a future where information and communication technology will allow its participation in its own development and progress, as well as in scientific networks which will demand reliability, low latency and huge quantities of real-time data.
References
Combrinck, L. 1998. A regional GPS network for southern Africa. Unpublished talk delivered at the 23-26 March 1998 International Workshop: GPS Geodetic Investigations and Infrastructure in the Greater Middle East Region, New Castle Upon Tyne.
Neilan, R. and R Wonnacott. 2002. Establishing a Continental Reference System in Africa, AFREF. Unpublished proposal to International Council for Science, February 2002.