Earth observation in South Africa and its impact on business
On 17 September 2009 South Africa’s first operational earth observation satellite (SumbandilaSat) was launched from the Baikonour spaceport in Kazakhstan on board a Soyuz rocket. This satellite is a microsatellite with a number of ‘payloads’. The primary payload is a multispectral imager (camera) that will be able to image the earth with a ground sampling distance (resolution) of 6.25 m. The satellite orbits the earth at an altitude of 500 km and takes approximately 15min to cross the sky from horizon to horizon at any one point on earth. SumbandilaSat is designed for a three year lifetime in orbit.
Earth observation satellite data has been in use in this country for a long time with the Council for Scientific and Industrial Research (CSIR), Satellite Applications Centre receiving, storing, processing and distributing data since the seventies. This data is used on a daily basis in a number of applications by both the public and private sector. The greater public has become aware of the usefulness of Earth Observation (EO) data since the advent of internet databases such as Google earth.
The use of remote sensing data in South Africa is well developed and spreads across the full spectrum of the Group Earth Observation (GEO) societal benefit areas. Some examples per societal benefit area include:
Use was made of Spot 4 and 5 and Modis satellite imagery by the Deportment of Provincial and Local Government (DPLGs) National Disaster Management Centre (NDMC) to monitor exceptional tidal wave events in KwaZulu-Natal in March 2007 and for the monitoring of veld fires in Mpumalanga in July 2007.
Development of the Active Fire Information System (AFIS) providing real time access to active fire data across SADC and availbale freely (current use extends up to Bujumbura).
Use of Spot 5 high resolution satellite imagery by the Department of Health is made to identify localities of Health infrastructure and service delivery strain on surrounding communities.
Use of Satellite data from the Ozone Monitoring Instrument (OMI) and SCIAMACHY by DEAT in modelling highveld air quality and emission exceedances.
Over 30 local honours, MSc and Phd research dissertations using remote sensing have been made to answer climate change questions.
Use of Landsat and Spot satellite imagery is made to validate and verify agricultural water use, in effect enforcing the Water Act.
Participation of South African Weather Services together with the Agricultural Research Council and CSIR in the African Monitoring of Environment for Sustainable Development (AMESD) programme is aimed at improving decision-making processes in the fields of environmental resource and environmental risk management in Africa.
Use of various satellite imagers by the South African Earth Observation Network (SAEON) is made in vegetation mapping, species change detection, climate change analysis, landcover and land use change.
Use of multitemporal medium resolution satellite imagery by DEAT is made to monitor socio and environmental pressures on protected areas and wetland monitoring as input to South Africa’s obligations to the RAMSAR convention.
Use of low, medium and high resolution satellite imagery by the Department of Agriculture is made for crop statistics, vegetation and soil status monitoring, drought assessment and as input to the Agricultural Geographical Information System (AGIS) (http://www.agis.agric.za/agisweb/agis.html)
Development of the Spot Building Count, an annual nation point data set derived from high resolution satellite data to determine the position and growth dynamics of populations (formal and informal) across the country is used for electrification demand forecasting. This information is being provided freely to municiaplities for planning purposes. North West Provincial Department of Housing is already using this data in the monitoring of informal settlements in the province.
In 2008, the United States Geological Survey (USGS) conducted a survey on the African remote sensing market. The study focused on ten year trends in aerial and spaceborne technologies. In broad terms, the study points out positive movement in the use of remote sensing and shows opportunities for the use of geospatial data to make an even greater societal contribution to Africa’s sustainable development in the foreseeable future.
The study also found that:
• the private sector is starting to drive the process of developing geospatial data on the continent as shown by the abundance of organisations involved in promoting the acquisition and use of geospatial data, such as the Gates Foundation, and the Mapping Africa for Africa (MAFA) initiative of the United Nation’s Economic Commission for Africa (UNECA); and
• government, academic and commercial communities, believe they have an adequate amount of remote sensing expertise and capability, but what they need is a greater number of accessible geospatial data sets.
SADC and South African trends in remote sensing are largely informed by the procurement of data and application related services from the CSIR SAC. In 2008 Mozambique and Botswana alone procured in excess of R10 million in high resolution satellite imagery. The total spend in SADC (excluding South Africa) is estimated at between R50 and 100 million with topographic mapping, food security, natural resource/heritage protection, homeland security and disaster management being the leading sectors.
In South Africa, the combined government and private sector spends on earth observation imagery has steadily increased from about R50 million in 2004 to approximately R150 million in 2008. Although this includes imagery derived from airborne platforms, that derived from satellite is becoming more dominant, particularly with the recent availability of 50cm colour satellite imagery, which is being actively used in applications previously serviced exclusively through airborne technology.
In 2006, eight national government departments, the Development Bank of South Africa (DBSA) and Eskom combined their earth observation budgets to secure access to high resolution earth observation data for the entire country for three years in a deal costing R80 million. Significantly, the terms of this access agreement were multi user licences for all government departments (national, provincial and local) as well as academia. The use of this data has been closely monitored and has shown over 200 end users across 16 government departments having accessed the data or parts thereof. The data was also used by over 150 students in the realisation of Honours, MSc and Phd dissertations. Recently, the data has been further disseminated with supporting geospatial data to all universities in the country though a computer programme dubbed “fundisadisc” to encourage applied research in this domain.
For what will SumbandilaSat be used?
While the applications mentioned so far are done using large international satellites, South Africa’s SumbandilaSat will be used in a number of unique applications. The Department of Science and Technology has commissioned a number of application projects.
These Projects include:
• Mineral Mapping and Spectral Validation of SumbandilaSat’s visible and near infrared sensors
• Assessment of SumbandilaSat’s potential to contribute to an integrated remote sensing air quality monitoring system in SA
• Identification of priority areas and core validation sites in South Africa for the acquisition of SumbandilaSat’s imagery
• Change Vector Analysis for surface and groundwater monitoring
• Evaluation of Vegetation Specific Applications for the SumbandilaSat, with focus on the red-edge and Xanthophyll wavelength ranges
Use of satellite imagery can be seen to be used actively in the public and private sectors and, with the launch of SumbandilaSats, South Africa can now add its own generated data to the protfolio of data being used in this country for spatial based decision making.
Eugene Avenant, BEng, is Manager: Telemetry Tracking and Command, CSIR Satellite Applications Centre.