“…The Canadian Space Agency started supplying RADARSAT data operationally to users in April 1996. Digital Satellite Images Medium-to high-resolution digital imagery from automatic unmanned satellites has been routinely available for most areas of the world, with the exception of parts of the tropics and the arctics since the early 1970s (Press and Rivereau, 1990). 19 The basic characteristics of the principal operational satellites that acquire data in the visible and short-wave infrared spectral bands are listed in Table 2.…”