All Sky Camera

The All Sky Camera looks up from the village of Bourn in Cambridgeshire, UK. It's fully weatherproof and images the sky 24/7. You can see clouds, stars, sun, contrails, clouds, moon, rain, clouds, and their movements across the sky. Clouds from the left, clouds from the right. Clouds from three different directions simultaneously. Did I mention the clouds? The time-lapse cloudscapes can be facinating and beautiful, if somewhat frustrating for astronomy.

The Sky Now

N
E all sky cam image loading... W
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image automatically refreshes once a minute   

Last Hour Animation

The all sky cam animated loop displays a loop of the last hour's worth of images. Each loop takes around 6 seconds to display and a new image is added into the loop once a minute. Useful for keeping track of the state of the sky as the night progresses.

Time-Lapse Movies

Movies are captured at one frame per minute, and played back at 10 frames per second. You see an hour of sky every 6 seconds. Click on the links below to view the movies.

Last Night
(6pm yesterday to 6am today)
5-10MB
Yesterday
(midnight to midnight)
5-10MB
Split Day
(midday to midday)
5-10MB

Alternatively browse and download older time-lapse movies. Movies prior to 20090630 have a different compass orientation: E up, W down, S left and N right.

Exemplars: Clouds dance, boil and churn. Clouds from the left, clouds from the right, plus contrails. Confused clouds, wind and rain. Cloudy day into clear midsummer night. Clear moonless midsummer night.

The movies are encoded in H.264/MPEG-4 AVC format. Windows Media Player may require a codec to be installed to view the movies. I would recommend the free Combined Community Codec Pack (CCCP) for this purpose. Alternatively Linux, Mac and Windows users can download and use the free VLC Media Player.

Technical

The current imaging system consists of a Mintron 12V1-EX integrating colour video camera, coupled with a Rainbow L163VDC4P fisheye lens. In low-light situations the camera internally combines multiple frames (up to 128) to image at star-light illumination levels. In addition we further integrate eight of these frames together offline to further smooth the image. At night the camera appears to be slightly more sensitive than dark adapted eyes, and is an excellent way of picking up high cirrus that would not normally be easily visible. The camera is housed in a weatherproof canister previously used to house a old lidar based airport cloud level monitor. The canister window has a tendency to dew-up during periods of high humidity. This needs to be fixed by adding a heater at some point. The camera's also exhibit a few bad pixels, which show up as "stars" that don't rotate across the screen.

The camera's video output is fed into an Eptascape ADS-200 video server. The box provides a live feed to any computer on the LAN. In addition to the all sky cam, the video servers also support an observatory monitoring camera and a western horizon facing "sunset" camera - the feeds for which are not accessible on this website.

Camera settings are controlled via an RS485/RS232 converter camera-to-PC connection and Mintron's camera control software (63V5H). The software requires RTS/CTS and DTR/DSR/DCD lines to be tied together (a Null Modem conversion), can only be used on the lowest numbered COM port, and then only COM1-3.

A Linux based server captures individual images from the video server, integrates eight frames together per minute to help reduce image noise, and creates and stores the various time-lapse movies. The heavy lifting is done with mencoder, and the system is glued together with simple shell script cron jobs.

History

The All Sky Camera started life in May 2008 and has been faithfully recording the sky, with the odd interruption due to hardware failures, ever since. The "SkyEye" server holds a publicly accessible minute by minute image and timelapse video archive.

The hardware and software has gone through various changes, mainly due to hardware failures. The original imaging system consisted of a Mintron 12V6HC-EX integrating mono video camera, coupled with a Fujinon YV2.2x1.4A-SA2 fisheye lens. This original mono system had to be replaced after the camera failed. The new colour system is less sensitive, but better illustrates the level of local light pollution - showing differences in colour between low and high clouds. Similarly the original video server was based on the Aviosys 9100B-RS upgraded with the Yoics firmware hack.

Early experimental nighttime timelapse movie using Canon 20D DSLR and Peleng Fisheye Lens.

Links

Similar setups, useful information, and professional observatory all sky cameras: The Cambridge IoA All-Sky Camera, MMTO Sky Camera, Cloudbait Observatory, JAT Observatory, MASCOT (ESO Parnal), LasCam (ESO La Silla), and The Night Sky Live (CONCAM).

All timestamps are UT/GMT. The All Sky Camera is your prototypical Tim and Paul co-production.

   
         
 
  Site contents and all images are Copyright © 2006-2010 Paul Beskeen