Re: [LEAPSECS] The opportunity of leap seconds

From: Peter Bunclark <psb_at_AST.CAM.AC.UK>
Date: Mon, 9 Jan 2006 08:03:09 +0000 (GMT)

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.
Received on Mon Jan 09 2006 - 00:04:33 PST