The Sundial Reader

An image from the Sundial Reader, when it was in operation

From the Lab roof we had a good view of the new Foundress Court sundial in Pembroke College. We built a vision-processing system which would deduce the time from the image.

Since the closure of the lab, the reader has not been in live operation, but here is an example image from its output, taken on Fri Apr 5 14:34:03 BST 2002

With this camera we could read the sundial to an accuracy of about 2 minutes. Sundial time is currently 2.7 minutes behind local mean time.

Local apparent time:	13:32
Local mean time:	13:35

More information on how we read the time from the image.
For more about sundials, see Sundials on the Internet.