Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2003 · 13 citations · 0 references
Natural SciencesAstronomyCelestial MechanicsObservational AstronomyOptical AstronomyGeometric CorrectionObservatory OperationsTelescope OpticsTelescope Pointing CalibrationAlignment MaintenanceGeometric Distortion CorrectionInductive SensorsMirror AlignmentMirror Misalignment CalibrationPerformance VerificationSegment MaintenanceTelescope Pointing Drift Correction
The Segment Alignment Maintenance System (SAMS) was installed on McDonald Observatory's Hobby-Eberly Telescope (HET) in August 2001. The SAMS became fully operational in October 2001. The SAMS uses a system of 480 inductive edge sensors to correct misalignments of the HET's 91 primary mirror segments when the segments are perturbed from their aligned reference positions. A special observer estimates and corrects for the global radius of curvature (GRoC) mode, a mode unobservable by the edge sensors. The SAMS edge sensor system and GRoC estimator are able to maintain HET's primary figure for longer durations than previously had been observed. This paper gives a functional description of the SAMS control system and presents performance verification data.