On Sun, 8 Jan 2006, Tom Van Baak wrote: > Peter, > > So where do these modern telescope get UT1? Do you or
The last time I was involved personally was during my time as a support astronomer at the Isaac Newton Group on La Palma in the early nineties. We had a radio receiver which required upcoming leapseconds to be entered manually ahead of time. This provided a one second per second UTC interrupt to the telescope control computers. The TCS computers were programmed with an upcoming leapsecond, and with the corresponding jump in DUT1. To compute fractions of a UTC second, the computer adds its own clock to the one-second interrupt count, which gives high precision. The whole system gives UT1 to high precision throughout a leapsecond event and beyond. Pete.