All-sky images taken from Dome A, Dome Fuji and Ridge A

Brief description

This dataset contains images of the sky taken with the HRCAM (High Resolution CAMera) instrument. HRCAM 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.

HRCAM was primarily designed by Daniel Luong-Van. Nick Tothill helped with construction. Michael Ashley helped with design, construction, software, and operation.

The directories here are:

/documentation PDFs of papers and a PhD thesis describing the instrument and results
/raw Canon RAW image files - these are the original images
/jpg JPG images extracted from some of the raw files
/thumbs Thumbnail images extracted from some of the raw files

Several versions of HRCAM have been built. You can tell which one is used from the serial numbers of the Canon EOS 50D camera, as stored in the RAW image files. Camera serial number 0330104673 was sent to Dome A, 2110703496 to Ridge A, and 2210700089 to Dome Fuji.

The image filenames in the various directories contain the UNIX epoch in seconds at which the exposure started. To convert the UNIX epoch to a date/time, you can use the Linux date command, as per the following example:

data -u -d @1282890600

Images from Dome A:

The original HRCAM was first installed in PLATO at Dome A during January 2010. The camera was refurbished and reinstalled in PLATO-A for 2015.

There are 12703 images, with cadences of 240 and 660 seconds (with different exposure times), taken from Dome A. The images are in raw/h1*.raw, and start with h1282890600.raw at Fri 27 Aug 2010 06:30:00 UTC, and end with h1295604000.raw at Fri 21 Jan 2011 10:00:00 UTC. In addition, there are 709 images, with cadences of 900 seconds in jpg/h12*.jpg, starting with h1282915324.jpg at Fri 27 Aug 2010 13:22:04 UTC, and ending with h1284925919.jpg at Sun 19 Sep 2010 19:51:59 UTC. In addition, there are 10339 images, with cadences from 120 to 1800 seconds, taken from Dome A. The images are in raw/h1-*.raw and jpg/h1-*.jpg, with thumbnails in thumbs/*jpg, and start with h1-1421930703.jpg at Thu 22 Jan 2015 12:45:03 UTC, and end with h1-1434252625.jpg at Sun 14 Jun 2015 03:30:25 UTC.

Images from Dome Fuji:

HRCAM2 was taken to Dome Fuji and installed in PLATO-F by the Japanese 52nd JARE expedition during the 2010/2011 season. In the images, 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.

There are 21336 images, with cadences of 240 and 660 seconds (with different exposure times), taken from Dome Fuji. The images are in raw/h1*.raw, and start with h1296361840.raw at Sun 30 Jan 2011 04:30:40 UTC, and end with h1310294940.raw at Sun 10 Jul 2011 10:49:00 UTC. In addition, there are 8487 images, with cadences of 900 seconds in jpg/h1*.jpg, starting with h1299704642.jpg at Wed 09 Mar 2011 21:04:02 UTC, and ending with h1310295070.jpg at Sun 10 Jul 2011 10:51:10 UTC.

Images from Ridge A:

HRCAM3 was taken to Ridge A and installed in PLATO-R during the 2011/2012 season by a team led by Craig Kuleas of the University of Arizona. In the images, the solar panels are at the top of the image, the Ubob cameras are at 40 degrees CW, the HEAT telescope is at 60 degrees, the SCAR flag is at 110 degrees, and the meteorological tower at 200 degrees. North is at approximately 20 degrees. The image reaches very close to the horizon in all directions.

There are 12730 images, with cadences of 300 seconds, taken from Ridge A. The images are in raw/h3-*.raw, and start with h3-1331181001.raw at Thu 08 Mar 2012 04:30:01 UTC, and end with h3-1335099900.raw at Sun 22 Apr 2012 13:05:00 UTC.

Processing the RAW images:

exiftool is a convenient piece of free software for processing Canon RAW images. dcraw can be used to extract images.

On a Linux computer you can use commands such as these:

To list all the metadata in a RAW file:

exiftool -all h1282890600.raw

To extract the PreviewImage and ThumbnailImage from a RAW file:

exiftool -b -PreviewImage h1282890600.raw - h1282890600.jpg
exiftool -b -ThumbnailImage h1282890600.raw - h1282890600-thumb.jpg

To copy metadata to a JPG file:

exiftool -tagsFromFile h1282890600.raw -exif:all -overwrite_original h1282890600.jpg