HRCAM: the high resolution all-sky camera

HRCAM (High Resolution CAMera) is a digital SLR camera (Canon EOS 50D; 15 megapixels) equipped with a fish-eye lens (Sigma 4.5-mm f/2.8) for all-sky coverage on a 1.6 crop sensor. It was installed in PLATO-F at Dome F during January 2011. It takes images of the sky above Dome F every few minutes for the purpose of determining the cloud cover, sky brightness, sky transparency, and aurora distribution.

Snodar An HRCAM image taken on 30 January 2011, after the Japanese 52nd JARE expedition had left Dome F. The green Engine Module is at the top of the image, two small iridium aerials are at left and bottom, the Iridium Openport antenna is in the insulated white box at lower left, the meteorological tower is also visible. The "egg of vision" is on the right, just above the Iridium aerial. The image reaches to the horizon in all directions.
Snodar The prototype HRCAM instrument (this one was deployed to Dome A in January 2010). The fish-eye lens is flush with the top, and does not have a window. The reflective metal cover is designed to shed snow, and have low emissivity so that it can be heated efficiently. The holes on the bottom left are for a dehumidifying system. The single Milspec connector provides 24VDC power and a 100Mbps LAN connection. The enclosure includes an ARM-based computer running Linux. The camera is controlled via a USB connection using gphoto2. The instrument is designed to operate down to -80C. The raw images are stored on an array of four spinning hard-disks inside PLATO. Exposure times vary from 1/2000th of a second to 120 seconds depending on the sky brightness, and are automatically set by the software. Thumbnail images (20kB in size) can be sent back via PLATO-F's Iridium satellite link. Our aim is to use the raw images to extract quantitative information on sky brightness in the three camera filters.


Primary designer: Daniel Luong-Van
Constructor: Nick Tothill
Principal Investigators: Daniel Luong-Van and Michael Ashley

Participating institutions in alphabetical order

UNSW University of New South Wales, Australia