Ed Davies wrote on 2003-07-24 11:12 UTC: > Perhaps a way of moving the discussion on would be to make a > list of applications requiring accurate Earth orientation > information: > > 1. Pointing telescopes. > 2. Pointing satellite dishes. > 3. Celestial navigation. > 4. Calculating the civil times of sunrise and sunset, lighting > up times, etc. > > Others?
Not many more, I guess. Perhaps: - Sundail designers and owners (will have to add an additional term to the equation of time) - Computer-aided design software used by architects for predicting shadows, illumination and thermal load. But I doubt they need (or use currently) the local solar time to within better than 30 minutes, and they are more interested for how many minutes a day the sun shines through a window, and less, at what exact (meaning < 30 min tolerance) civilian time this starts and ends. Don't forget in this discussion that abandoning leap seconds will only increase the maximum difference between local civilian time and local solar time from currently 30 minutes (at places such as China and Western Europe much worse) to 60 minutes, because as long as DST is in use, local civilian times will have very little problems following local solar time with leap hours. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__
