Utilization of orthophotographs in the mapping of high mountain regions (eastern Alps, Vernagtferner glacier map).

Photogrammetry has played a major role in the recent progress of high-mountain cartography. Air photographs (central projection) can be used to produce orthophotographs (parallel projection). These orthophotographs not only display true distances, like maps, but they can be published directly as orthophoto maps. They can also be used as stereopairs and this provides additional information on the relief of the area represented. This paper illustrates the various qualities of orthophotographs with examples from the eastern Alps, and includes a glacier map of the Vernagtferner.-Author