Topographic Information in High-Resolution Images of Io

Abstract

Over four years distant observations if the jovian moon Io were taken by the spacecraft Galileo (dist > 120 000 km). This dataset was useful for improving shape models of Io and gave a global view on large topographic features. An important step with respect to image resolution was made with the close flybys at Io in october and november 1999 resulting in more than a hundred images with resolutions improved by a factor of more than 100 down to 9 m/pixel. A large portion of the new images were taken close to the terminator optimizing the visibility of topography due to shadows. In individual cases height measurements can be made with an accuracy down to one meter. While data is still arriving on earth (dec. 99) and a further close flyby at Io is planned for february 2000, height measurements of mountains and caldera walls have started. Results will be presented.