All Sky Imager Systems (ASIS) are deployed at Casey, Davis, Macquarie island and Mawson. These systems are autonomous data collection systems which record All Sky Imager data during periods of darkness at the stations.
The data are collected using a monochromatic video camera fitted with an Image Intensifer and a Fish eye lens. A filter (normally 558 nm) is also fitted to the cameras. (this can ... be varied at Davis but the filter in use) is stamped onto the image)
Images are digitised by a controlling PC and written to hard disk as JPEG images. Images are sorted into daily folders and returned to Australia annually for processing into MPEG files for each UTC day.
The end result is a short All Sky movie containing images for the periods of darkness between 0000 and 2359 UTC each day of the year. Each MPEG file has a short preamble which shows the Station latitude and longitude as orientation information. Each frame is stamped with time, date, filter and exposure information.