RECOVERING THE ATTITUDE OF THE HUYGENS DESCENT MODULE USING DISR DATA

摘要

Data from a combination of DISR instruments will allow probe attitude reconstruction during the descent phase. The radiances measured by the DISR Sun Sensor (SS), Side-Looking Imager (SLI) and Solar Aureole (SA 1, 2, 3 and 4) cameras as they are exposed to different sections of Titan sky and surface while the descent module spins, will be compared to a model of the satellite's absolute sky brightness in order to discern deviations from a baseline simulation with no tips or tilts. Thus the attitude of the probe can be deduced. Deriving the attitude allows High-Resolution Imager (HRI) and Medium-Resolution Imager (MRI) ground tracks to be assembled by correlating ground features from image to image and altitudes determined from SLI measurements of the level of the horizon. Hence the descent trajectory can be determined.