All Sky Camera Project

Page Created: 2003 August 27
Page Last Updated: 2008 November 21

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Home * Image Gallery * Image Archive * Design Notes * Construction Notes * Link Notes * SCO Yarker (SCO) ClearSkyClock

last 20 images from Camera1 * Sky Quality Meter data.

Recent modifications:

2008 Nov 20: webcam installed and operational. No heating in dome and it is frosting over something fierce. Using Homewatcher 2.0 at the moment set to motion detection mode.

2008 July 12 - still out of service. Will install regular webcam shortly and set for motion detection and at least get some daytime sky imagery.

2007 January 07 - Watec camera not giving pictures at all, only what look like strange moving bands of unsynchronized frames. Attempted to use new heater (two 10 ohm 10 watt wire round resistors in series giving 20 ohms which works out as 12vdc/20ohm=0.6 Amps. 0.6 Amps x 12vdc = 7.2 watts of heat. The resistors are rated for 10 watts so this should work out. As it turns out.. maybe not. The battery voltage dropped to 10 volts when this heater was plugged in, inside the allsky camera housing. They actually got hot to the touch as well. Still no image coming in from the camera so it has been removed for more study, the heaters have been removed and the 12vdc 1 watt circulation fan has also been turned off. 2006 December 31 - new housing complete and installed. EastWebcam slightly reaimed.

2006 December 28 - removed entire dome assembly, shortened post by 24" to match the newer northeastern post (CONCAM). Added more stabilizer supports to the post. Mounted new weather station wind sensor to the post along with its transceiver and solar panel. Built similar housing to that of the new CONCAM. The new low light camera will be mainly inside the housing with only a little of the lens poking out into the dome. The top platform was cut to a 14" diameter and then 1/4" was cut off all the way around, giving a 13.5" diameter circle. This way the 14" dome will hang slightly over the edge of the plywood. There are two 2.5" ventilation holes set diagonally. One will have a small 12vdc muffin fan blowing warmer air from the housing and into the dome. The existing watec902 camera and lens assembly was measured and a hole in the centrepoint of the top platform circle was cut. 2 1/4" in diameter. The camera and is lens and cables are just over 6" tall so it will jut out into the dome less than 1". The webcam, previously located inside the dome, will now be placed inside the housing looking out horizontally through a window, with the top platform overhanging, hopefully preventing the webcam from being covered up as in the past when snow and ice built up on the dome. The housing has a 2 1/4" vent hole in the bottom covered with anti-bug mesh on the inside and will have a movable cover on the outside.

2006 June 20 - replaced the $20 webcam with a watec HT902 ultra lo light monochrome camera and a wide angle rainbox lens looking up. There appears to be some dust on the sensor or in the optical system. This setup is equipped with an autoiris system which should allow daytime/nighttime use. The new hardware chain looks like this: watec camera with composite video output, a bayonet adapter, a 1m shielded video cable to a female-female coupler inside a junction box, a 5m shielded video cable to a VStream 2800 video-usb2 converter (about $100), into a USB2 PCI adapter card (about $25) inside a P4-1800MHZ workstation running homewacher v2 under Windows XP. Homewatcher saves local archives of images on a motion detection system and uploads up to 50 of the latest images to this website.

2006 May 28 - the webcam was shifted to look at the eastern horizon in preparation for the low light camera to be installed covering the zenith. The nichrome wire heating system was removed from the dome as it had shorted out, ramped up from 7 to over 20 watts, killed the deepcycle battery in the observatory that was powering it, and the wire actually came apart in three places. On consultation with other allsky camera operators, the lo light supercircuits camera may generate enough heat all on its own to keep the dome clear in normal operations, about 12 watts. The webcam is not very light sensitive and can barely pick out the moon, much less any stars.

2006 January - the system is running under windowsnt2000 on a P4-1700MHz (640mbRAM) workstation with web camera motion detection software called Homewatcher. We plan to move this to a linux based workstation using the software package Motion, a 300kb tarzip file.

2005 August 01 - a new system was built from the ground up and is now online. The components are: a hemispherical glass dome housing a camera ($50) a logitech USB quickcam express camera ($20) a wood platform atop an 8' 4"x4" post attached to the observatory a junction box located under the platform for 12vdc electrical (heaters), USB connector and a composite video connector for future use. a 5 meter USB 2 active repeater cable ($25) for the USB webcam from KCP. It runs from the pole mounted junction box into the observatory and into the workstation. a workstation running MS Windows NT2000. P3-500 with 512 mb RAM. (2006 January P4-1700 with 640mb RAM - doubling as an observatory computer with astronomy software - carte du ciel, virtual moon atlas, starry night v3, ECU, firefox web browser and hopefully video capture for a camera attached to a telescope). A $20 PCI USB2 card with 4 ports (the existing computer only had USB v1.1 and that could not handle the video bandwidth as well as everything else). Image capture software Homewatcher v2.0, set to take an image every seconds and compare it to the previous one. It has many issues (stopped development in 2002, unreliable in uploading, doesn't save files with datestamp), but is a starting point. Other issues: the webcam has a small field of view (my guess is about 50 degrees), and needs to have a wider field of view. It is also not very low light sensitive, so any meteors it does see will not have background stars for calibration. The webcam resolution is quite poor. And the homewatcher software needs to capture at least 2 or 4 frames per second and store more than a few dozen or hundred images.

This is a work in progress and is the 2nd generation design.