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.

       
Please send back the questionnaire to iers@obspm.fr

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