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First directly-received Landsat 7 satellite image
 The CSIR Satellite Applications Centre (SAC) received its first directly-acquired Landsat 7 satellite image, captured by this earth observation satellite on 20 February 2001. The image is a spectacular image acquired over central Namibia and demonstrates the satellite’s abilities to capture detailed features on the ground. Landsat satellites have been documenting the Earth’s surface for more than a quarter of a century and South Africa’s National Earth Observation database at the SAC dates back to 1980.
The direct acquisition followed weeks of upgrading, testing and integration and close co-operation between the SAC and specialists from the Italian satellite reception and processing software company, ACS, who had been contracted to assist with the upgrade.
"Buyers of satellite imagery are expected to react positively to the introduction of Landsat 7 data since its additional panchromatic band, with a resolution of 15 metres, will lead to better products. What will prove to be of equal significance, however, is the fact that this imagery will be coming directly in to South Africa via the SAC, where value-addition can be done on-site in the Geo-Information Products and Solutions (GIPS) facility,” says GIPS Manager at the SAC, Dr Ferdi Scheepers.
"Experience internationally is demonstrating that the applications in which satellite imagery are used, require a rapid response. Meeting this requirement has been problematic in many cases due to satellite tasking, reception and value-adding facilities being widely separated geographically. Direct reception enables us to respond immediately,” he says.
The upgrade to Landsat 7 followed an investment by the South African Department of Agriculture, for whom the availability and the regular acquisition of Landsat imagery, is key. Landsat 7 imagery is particularly suited to agricultural applications such as crop yield,
geo-exploration, land cover and land use assessment.
"The cooperation between the SAC and the National Department of Agriculture to receive Landsat 7 imagery will hugely benefit South Africa. Imagery is automatically captured – with intervention and specific programming possible - and archived to the SAC National Earth Observation Database. The time span of the database enables scientists to do change studies over a period of time,” says Scheepers.
Landsat 7 was launched from Van Den Berg Airforce base in October 1999 and is operated and managed by the United States Geological Survey (USGS). Investments to receive Landsat 7 imagery at the SAC only commenced once the satellite had been launched and captured data successfully, since a failed launch – such as that of Landsat 6 – could result in significant financial losses.
Reporting from Maspalomas, Spain, where she attended the Landsat Technical Working Group meeting, Helena Bosman, Manager: SAC Systems Management and Support, says South Africa’s progress towards reception capability had been followed with interest by the other stations in the global network, who were all represented at the meeting.
"One of the issues that received special attention was that of compatibility of standards and formats for data exchange. This will facilitate ready exchange of Landsat 7 data amongst ground stations, but, more importantly, it will ensure that clients world wide reliably receive products of the same high quality,” she says.
The SAC now receives imagery from the following satellites - NOAA, Landsat 7, Spot 1, Spot 2, ERS 2 and Orbview 2.
Issued by: CSIR Satellite Applications Centre.
Further Information:
Media enquiries: Alida Britz Technical Enquiries: Ferdi Scheepers
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