Opposite-side radargrammetry of Magellan synthetic aperture radar on Venus

초록

In the early 1990s, synthetic aperture radar onboard Magellan spacecraft has imaged 54% of the Venusian surface in the opposite-side stereo configuration while only 21% in the same-side. Much of the data for the opposite-side radargrammetry (OSR) on Venus were underutilized due to higher topographic distortion than the same-side radargrammetry (SSR). In this paper, the performance and limitations of the OSR are demonstrated based on an example over Lullin impact crater, Venus. The initial stereo match points are classified into three categories; GOOD, BAD, and TOPO, and different methods are suggested for each category to improve the quality of digital elevation model. Large areas of gentle slope on Venusian volcanic plain can be successfully matched using conventional stereo-matching algorithm. Image contrast of featureless surface can be improved by enlarging the master image patch at a cost of spatial resolution, while high to moderate relief regions need further treatments such as radarclinometry. Utilization of OSR is expected to provide additional DEM dataset of Venus and to give flexibility for the design of future planetary SAR missions.

키워드