1、 QUESTION ITU-R 236/7*,*The future of the UTC time scale (2001) The ITU Radiocommunication Assembly, considering a) that the procedures for maintaining the Coordinated Universal Time (UTC) time scale are described by Recommendation ITU-R TF.460; b) that UTC is the legal basis for time-keeping for mo
2、st countries in the world, and de-facto is the time scale used in most others; c) that Recommendation ITU-R TF.460 states that all standard-frequency and time signal emissions should conform as closely as possible to UTC; d) that Recommendation ITU-R TF.460 describes the procedure for the occasional
3、 insertion of leap seconds into UTC to ensure that it does not differ by more than 0.9 seconds from the time determined from the rotation of the Earth (UT1); e) that the occasional insertion of leap seconds into UTC creates serious difficulties for many operational navigation and telecommunication s
4、ystems today, decides that the following Question should be studied 1 What are the requirements for globally-accepted time scales for use both in navigation/telecommunication systems, and for civil time keeping? 2 What are the present and future requirements for the tolerance limit between UTC and U
5、T1? 3 Does the current leap second procedure satisfy user needs or should an alternative procedure be developed? further decides 1 that the results of the above studies should be included in (a) Recommendation(s); 2 that the above studies should be completed by 2011. _ *In the year 2009, Radiocommun
6、ication Study Group 7 extended the completion date of studies for this Question. *This Question should be brought to the attention of the Bureau international des poids et mesures (BIPM), the International Earth Rotation Service (IERS), Study Group 13 of the Telecommunication Standardization Sector and Radiocommunication Study Group 8.
