About the Blackboard Technology Group WeatherCam

The Blackboard Technology Group WeatherCam was operational for 5 years, ending in the Spring of 2002. The outdoor images were taken with an IndyCam that was connected to a Silicon Graphics Indy R5000 workstation. A crontab script ran at 5 minute intervals to record a new image. Although the IndyCam had automatic gain control, the dynamic range of the camera was insufficient to handle the wide range of exterior lighting conditions. An iterative procedure was invoked immediately prior to taking each image. This procedure took a test image, analyzed it for lighting balance, and adjusted the shutter speed of the camera. Then the actual image was taken and converted to JPEG format.

Next, a thumbnail copy of the JPEG image was created and the original JPEG image annotated using John Cristy's Linux convert program. Both the thumbnail and annotated image were transfered from Blackboard Technology Group's internal network to their Web server.

On the Web server, crontab scripts ran every hour, every afternoon at 1:00, and on the first and fifteenth of the month to update the image archives. A user snapshot facility, that allowed anyone to save the current image in a user's choice database, was implemented as CGI scripts.

The IndyCam had a wide-angle lens designed for close-up work. Therefore, objects in the WeatherCam images are actually much closer than they appear.

On dark, cloudy days, the images were dark--just like the view out the window.