Geometry of Fan Beam Albedo Measurements on Spin-Stabilized Satellites

摘要

Because there is an imminent danger that most of the existing expert knowledge about attitude determinationnusing fan beam albedo sensors on spin-stabilized satellites may become unavailable, it seems worthwhile tonsummarize this material in an archival paper. Toward this goal, all still-accessible reports and notes dealing withnattitude reconstitution based on albedo slit sensors have been scrutinized.Onthis basis, we assessed the state of the artnthat was reached some decades ago; subsequently, no new satellite projects were realized that made use of this stillinterestingntype of attitude sensors. In the analysis of the available material, it appeared that attitude measurementnstability and estimation accuracy still faced problems during particular time periods. In this context, elements havenbeen identified that had been omitted from the ground-based attitude operations. These elements essentially concernnthe exclusion of specific measurement geometries, which, with certainty, invalidated certain measurements duringntime intervals of nonnegligible duration. The reported estimation concepts of the past have been updated not only onna theoretical basis, but also in light of more recent insights and operational experience gained from infrared sensingnon spinning satellites. All this is included in a comprehensive and self-contained presentation based on the geometrynof fan beam albedo sensing and its practical operational implementation.