A new all-sky optics for aurora and airglow imaging

• Main Authors: Makoto Taguchi, Masaki Ejiri, Kei Tomimatsu
• Format: Report
• Language: English
• Published: National Institute of Polar Research/National Institute of Polar Research/Nikon Engineering Co., LTD. 2004
• Subjects: all-sky imager; aurora; airglow; optical imaging; Syowa Station; Antarc*; Antarctica; polar night; Advances in polar upper atmosphere research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6389; http://id.nii.ac.jp/1291/00006389/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6389&item_no=1&attribute_id=18&file_no=1

This report reviews the initial performance of a new all-sky imager (ASI-2) that utilizes commercial lenses and a high-sensitivity cooled CCD camera. The use of a commercial fish-eye lens as an optical front end and a standard camera lens as a final imaging lens makes the ASI-2 optics smaller, lighter and less expensive than the original ASI optics, with minimal degradation of optical performance. Despite the lower production cost, the speed of the ASI-2 lens system is not markedly slower than the ASI optics, with speed slightly faster than half the speed of ASI. Although the motors driving bandpass filter switching and focusing have been removed to reduce weight, the narrow bandpass filter can be exchanged manually to select specific emission lines, and focusing can be performed manually using a micrometer. The optical performance of the ASI-2 optics is measured and shown to be sufficient for auroral and airglow imaging. The ASI-2 optics is currently installed at Syowa Station, Antarctica, and is involved in observations during the 2004 polar night season.