All-sky 10 μm cloud monitor on Mauna Kea

摘要

We report an infrared all sky cloud monitor operating at Subaru telescope at Mauna Kea, Hawaii. It consists of panoramic optics and a 10 μm infrared imager. Aspheric metal mirrors coated with gold (sapphire over-coated) are used in the panoramic optics, which is similar to the MAGNUM observatory's cloud monitor at Haleakala, Maui. The imager is a commercially available non-cooled bolometer array. The system is waterproof and (almost) maintenance-free. The video signals from the imager are captured, averaged over 50 frames, subtracted clear-sky frame and flat-fielded in two minutes interval. The processed cloud images are transferred to Subaru observational software system (SOSS) and displayed combined with telescope/targets information and also stored to Subaru Telescope data archive system (STARS). The processed images will be opened on Internet web site.