costsabout 18 American dollars. Since such a large area is coveredin a single frame, the CORONA photographs provide asynoptic view of the terrain like the modern satellite images.This will help in understanding the regional landscapefeatures (Fig. 1). Scanning the negative film strips of thesephotographs gives better positive digital outputs compatibleto computer processing for the creation of vector data layersand comparing with other datasets. Even at 600 dpi, thephotographs stand enlargement to their full spatial resolutionshowing the surface details very clearly (Fig.2).Nageswara Rao et al. (2003) found the CORONAphotographs useful for accurate mapping of the beach ridgesin the Godavari delta area, which could not be decipheredfrom the modern remote sensing images as these coastalsandy linear features representing the former shorelinepositions are mostly obliterated due to the recent intensiveland use practices (Fig.3). There is another advantage ofthe CORONA photographs. They are excellent record ofthe conditions prevailing more than four decades ago.Nageswara Rao (2006) identified the coastal landformchanges on decadal scale by GIS analysis of the scannedCORONA photographs and the recent satellite dataproducts, which in turn helped in understanding theshoreline dynamics in the Godavari delta (Fig. 4). The stereocoverages of CORONA, wherever available, were alsofound useful in conjunction with field surveys throughdifferential global positioning systems (DGPS) for creatingdigital elevation modelsand to generate fairly accuratecontour maps through digital photogrammetric techniques(Schmidt et al. 2001; Galiatsatos et al. 2005).The inexpensive and high-resolution CORONAphotographs have become a good mapping source for theinternational scientists (Kumahara and Nakata, 2001) whoCORONA satellite photographs are a welcome sourceof data for the earth science community, especially incountries like India. CORONA was a code name for theseries of photo-reconnaissance satellites launched byU.S.A. during 1959-1972 meant for surveillance of theSoviet block of countries in the cold war era (Wikipedia,2008). These orbiting satellites used conventionalphotographic techniques by employing cameras loaded withfilm to capture the earth surface details. This was beforethe invention of the digital technology, which is currentlyused in all the polar orbiting remote sensing satellites. Therecovery of the film exposed by the CORONA satelliteswas very interesting. The reentry of the canister ofthe exposed film ejected from the CORONA satellites wasthe first man-made object to return from the earth orbit(David, 2004). This was designed to withstand theatmospheric conditions at 150 to 200 km above the earthsurface with a heat shield that could be jettisoned and aparachute that could be deployed when the canister reentersthe atmosphere (Galiatsatos, 2004). The telemetry signaland strobe lights would also turn on after its reentry so thatthe U.S. Air Force carriers that were deployed for suchprecise recovery job could locate it, snatch it in the midairby its chute cords and haul it onboard (Galiastatos, 2004;Schmidt et al. 2001). This recovery task was always carriedout over the oceans. Of course, this mid-air acrobaticsfailed number of times, but the film capsules were designedto be in tact even if they fall into water so that they couldbe recovered by the U.S. Navy ships on patrol, or, afterfloating briefly would sink into ocean to prevent its recoveryby others (Galiatsatos, 2004). It is heartening to note thatthese photographs are made available for civilian usesince 1995.The CORONA satellite photographs are of very highspatial resolution of ~3 m (Bayram et al. 2004). The systemparameters and types of cameras and films used in the