New satellite image mosaic of SA launched

19th June 2013 By: Keith Campbell - Creamer Media Senior Deputy Editor

New satellite image mosaic of SA launched

The 2012 Spot 5 mosaic of South Africa
Photo by: Sansa

The South African National Space Agency (Sansa) officially unveiled the “Spot 5 National Mosaic 2012” on Wednesday. This is a mosaic which covers the entire country and is composed of images taken by the French Spot 5 Earth observation 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 Sansa CEO Dr Sandile Malinga. “They say a picture is worth a thousand words – a satellite image has a wealth of information and is worth a million words.”

“The Spot mosaic represents a commitment that Sansa has made, to provide quality data and services to a variety of users,” explained Sansa Earth observation stakeholder and new business development manager Imraan Saloojee. “It is used for decision-making as well as [being] used to bring benefits to society.”

Sansa distributes the mosaic to national government departments and agencies, all nine provincial governments, and some State-owned companies. These recipients include the departments of Agriculture, Forestry & 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 of itself is of little value, unless it is used.”

It takes almost exactly a full year to acquire all the images required to provide total coverage of the country. The first image for the current 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.

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