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Space agency boosts earth observation, launches new satellite image mosaic of South Africa

The South African National Space Agency (Sansa) has increased its earth observation (EO) budget this year to R70-million. “This is a 13% increase on last year’s expenditure,” reports Sansa CEO Dr Sandile Malinga. “The biggest [part of this] spend goes to data acquisition – about R30-million, for imagery from [French EO satel-lite] Spot and [US EO satellite] Landsat and other global satellites and then to improve our systems and turnaround times, so as to improve our service to our customers.”

The agency is also investing in improving its catalogue access system. It holds data going back as far as 1972. “It’s a wealth of information,” he highlights. “We continually have to migrate this data from one medium to another. This data migration, or archive migration, involves significant expenditure.”

Another activity that Sansa is pursuing and which falls under EO is the creation of what is called base infor-mation. Base information pro-vides the foundation for the development of comparative indices allowing satellite data to be used to track changes in environments, whether natural or the result of human activity. For example, vegetation indices and urban development indices.
Recently, Sansa officially unveiled the Spot 5 National Mosaic 2012. This is a mosaic which covers the entire country and is composed of images taken by the Spot 5 satellite last year.

The 2012 edition is the seventh such mosaic of the country compiled from Spot imagery. “We want to ensure that we acquire the data we require as a country,” said Malinga at the launch of the mosaic.
“They say a picture is worth a thousand words – a satellite image has a wealth of information and is worth a million decisions.”
“The Spot mosaic represents a commitment that Sansa has made to provide quality data and services to a variety of users,” explained Sansa EO stakeholder and new business development manager Imraan Saloojee at the same function.“It is used for decision-making as well as to bring benefits to society.”
Sansa distributes the mosaic to national government departments and agencies, all nine provincial governments, and some State-owned com-panies. These recipients include the departments of Agriculture, Forestry and Fisheries, Communications, Defence, Environmental Affairs, and Home Affairs; the South African Police Service, the South African National Roads Agency, the South African National Parks, Statistics South Africa, and national electricity utility Eskom, among others.
“The economic value of this mosaic, this satellite data, is in its utility,” stated Department of Science and Technology space science and technology chief director Humbulani Mudau. “If this data is not utilised, for making informed public decisions, we will have missed a chance. _“Data in itself is of little value, unless it is used.”

It takes almost a full year to acquire all the images required to provide total coverage of the country. The first image for the cur-rent mosaic was taken on January 3, 2012, and the last on December 23. Each ‘tile’ in the mosaic covers an area of 60 km by 60 km. The new mosaic features several improvements over the 2011 edition, which suffered from some issues of colour balancing and gaps in the coverage. As a result, Sansa developed an improved method of colour balancing and a better true colour algorithm. And there are no gaps in the 2012 mosaic. Better Coverage

Sansa plans to provide even better coverage in future. “We are in the process of contracting for next-generation satellites Spot 6 and Spot 7, which will be much superior,” reported Malinga. “We have now contracted for Landsat 8.”

Sansa is composed of four divisions – Earth Observation, Space Operations, Space Science and Space Engineering.
Edited by: Martin Zhuwakinyu