Subject: Questionnaire regarding the use of UTC Dear colleague We are addressing the attached questionnaire to users of Bulletin C and/or D in order to survey opinion concerning a possible redefinition of UTC. UTC (Coordinated Universal Time) is computed from TAI by the introduction of leap seconds such that UTC is maintained within 1 second of UT1. Since 1972, these leap seconds have been added on December 31 or June 30, at the rate of about one every 18 months. The relevant bulletins are:
Bulletin C: Announcement of the leap seconds in UTC. Bulletin D: Announcement of the value of DUT1 truncated at 0.1s for transmission with time signals.
Recently, some communities linked to telecommunications and navigational systems have proposed a revision of the definition of UTC to avoid the discontinuities due to the intermittent leap seconds. The object of our survey is to find out the strength of opinion for maintaining or changing the present system within Bulletins C and D users. We would also like to know your interests and needs, current and future. I apologize if you receive this questionnaire twice. Thank you for devoting some of your time to this important topic. Daniel Gambis Head Earth Orientation Center of IERS ============================================================================= Please return this form by 30 June 2002 to the IERS Earth Orientation Center: iers@obspm.fr Thanks for your time and attention. Mark your answer with a X [X] and add any comments. 1 - Your identification Name : Institute: Adress : e-mail : 2 - Field of activity Time [ ] Telecommunication [ ] Astronomy/Astrophysics [ ] Geophysics [ ] Space sciences [ ] Geodesy [ ] Navigation [ ] Other? What? [ ] 3 - Are you satisfied by the current UTC determination method with leap second adjustements? YES [ ] NO [ ] 3-1 if YES Is the present forecast time (6 months in advance) of the occurence of a leap second sufficient. If not would you suggest another time delay? 1 year or more? 3-2 if NO Why ? 4 - Do you think it would be better to change the determination method of UTC? YES [ ] NO [ ] NO OPINION [ ] 4 -1 If YES, which alternative solution would you favour? a. No leap second [ ] a.1 UTC without further leap seconds [ ] a.2 Use TAI [ ] b. Increase tolerance for |UT1-UTC| [ ] c. Smooth over leap second step [ ] d. Redefine the second [ ] e. Some other possibility ? [ ] 4-2 If NO for 4, why? 5 - Other comments regarding the determination or operation of UTC? 6 - This question concerns Bulletin D users (DUT1 with 0.1s accuracy). Is the present Bulletin D appropriate ? YES [ ] NO [ ] If NO, why? If NO, would you prefer a more frequent and refined estimation? With what accuracy? END OF THE QUESTIONNAIRE