On-Chip Guiding with a Mosaic of HAWAII-2RG Infrared Detectors

摘要

This paper presents the guiding acquisition system for the CFHT WIRCam based on a mosaic of four HAWAII-2RG infrared detectors. This camera was designed and built by the Canada-France-Hawaii Telescope Corporation in collaboration with the Laboratoire d'Astrophysique Expérimentale of the Université de Montréal. The guiding system features four SDSU-3 boards modified to support dual optic fiber connections (master scientific and slave guiding) to allow simultaneous but independent guiding and scientific acquisitions. Stable and fast guiding at 50 Hz has been effectively achieved in infrared both in laboratory and on sky. The original SDSU software driver has been modified to support an interrupt-driven loop that automatically extracts one centroid from each of the four user-defined regions (one for each detector). The derived correction drives a PID closed loop Image Stabilization Unit (ISU) controller to effect guiding.