"High-resolution imagery is no longer exclusively used in the military domain," says Alex Fortescue, Business Manager: High Resolution Imagery at the Satellite Applications Centre. "The commercial availability of high-detail, rapid-revisit images opens up a wealth of new applications including traffic monitoring (since distinction between cars, minibuses and buses can now be made); real estate and asset management; transportation applications; and insurance verifications. Furthermore, these images will expand existing applications such as disaster management, urban development, mapping, environmental assessments and demographic compilation," he says.
Two international high-resolution satellites have been launched successfully, the first one, IKONOS, in 1999 (for which SAC has a distribution agreement) and the EROS satellite of ImageSat International, headquartered in Cyprus, on 5 December 2000. The Satellite Applications Centre has installed a Ground Receiving System at its Hartebeesthoek site to directly receive imagery when EROS - a polar-orbiting satellite - passes over Africa.
The first directly-received image was captured at 09:33 on Monday 11 June 2001 and is a scene of Kimberley and the well-known De Beers hole. It demonstrates the satellite's ability to capture extremely detailed features on the ground with roads, vehicles and railways clearly visible. While arbitrary images over southern Africa will continue to form part of the testing phase, buyers will soon be able to identify the areas needed, whereafter the satellite will be programmed and the data received and recorded - all in near-real time.
Explaining the technical detail of the imagery, Fortescue says the satellite has a swath width of 12.5 km, meaning that the area it captures in one image is 12,5km by 12,5km. While the resolution is 1.8m - which implies that features with dimensions in the order of 1.8 m can be seen from space - oversampling techniques will improve it to 1.2m.
All EROS images received at the SAC will go into an online archive. Electronic browsing, distribution and electronic-commerce will provide customers with cost effective, quick and easy access to high-resolution information.
ImageSat is an international company established in 1997 to provide geospatial information products and services from a constellation of high-resolution satellites to be placed in orbit over the coming years.