ISSN 1143-1393 Circular T 156 (2001 January 15) Circulaire T 156 1 - Coordinated Universal Time UTC. Computed values of UTC-UTC(k). (From 1999 January 1, 0h UTC, TAI-UTC = 32 s) Date 2000 0h UTC Nov 26 Dec 1 Dec 6 Dec 11 MJD 51874 51879 51884 51889 Laboratory k UTC-UTC(k) (Unit is one nanosecond) AOS (Borowiec) -2713 -2746 -2752 -2746 APL (Laurel) 6995 7018 7049 7076 AUS (Sydney) 100 85 70 35 BEV (Wien) -390 -383 -378 -372 BIRM (Beijing) 89 76 68 60 CAO (Cagliari) -3246 -3239 -3230 -3215 CH (Bern) -144 -146 -146 -148 CNM (Queretaro) -147 -151 -153 -154 CRL (Tokyo) -49 -54 -48 -48 CSAO (Lintong) 50 47 47 38 CSIR (Pretoria) -1215 -1278 -1325 -1400 DLR (Oberpfaffenhofen) -15713 -15886 -16059 -16236 DTAG (Darmstadt) -501 -483 -457 -435 GUM (Warszawa) -1 -1 17 18 IEN (Torino) 51 55 53 51 IFAG (Wettzell) -3374 -3399 -3396 -3401 IGMA (Buenos Aires) 63 75 85 112 INPL (Jerusalem) -219 -232 -256 -271 IPQ (Monte de Caparica) 5396 5451 5502 5553 JATC (Lintong) -4676 -4718 -4747 -4797 KRIS (Taejon) 81 100 94 92 LDS (Leeds) - - - - MSL (Lower Hutt) - - - - NAO (Mizusawa) -1970 -1935 -1907 -1873 NIM (Beijing) -2758 -2766 -2771 -2756 NIST (Boulder) -18 -16 -14 -9 NPL (Teddington) 22 22 24 23 NPLI (New-Delhi) 8565 8616 8673 8720 NRC (Ottawa) 45 45 46 54 NRLM (Tsukuba) 3739 - - - OMH (Budapest) 5163 5168 5174 5183 ONBA (Buenos Aires) -84 -58 -64 -69 ONRJ (Rio de Janeiro) 3123 3138 3155 3165 OP (Paris) -3 1 -2 2 ORB (Bruxelles) 24 -9 2 40 PSB (Singapore) 2191 2201 2223 2246 PTB (Braunschweig) 12 15 21 21 ROA (San Fernando) -89 -93 -85 -78 SCL (Hong Kong) 27 24 24 14 SMU (Bratislava) -3809 -3833 -3840 -3846 SO (Shanghai) - - - - SP (Boras) -278 -275 -257 -245 SU (Moskva) 103 104 104 105 TL (Chung-Li) -125 -118 -109 -115 TP (Praha) 128 132 135 136 UME (Gebze-Kocaeli) -412 -412 -413 -416 USNO (Washington DC)(USNO MC) 6 4 4 3 VSL (Delft) 31 27 34 41 BIPM , T 156 (2) 1 - Coordinated Universal Time UTC. (Cont.) Date 2000 0h UTC Dec 16 Dec 21 Dec 26 Dec 31 MJD 51894 51899 51904 51909 Laboratory k UTC-UTC(k) (Unit is one nanosecond) AOS (Borowiec) -2694 -2682 -2627 -2553 APL (Laurel) 7114 - - - AUS (Sydney) 13 -4 -15 -17 BEV (Wien) -376 -378 -373 -365 BIRM (Beijing) 56 51 49 45 CAO (Cagliari) -3202 -3209 -3206 -3202 CH (Bern) -142 -138 -129 -133 CNM (Queretaro) -146 -138 -153 -153 CRL (Tokyo) -39 -33 -32 -32 CSAO (Lintong) 37 64 52 38 CSIR (Pretoria) -1474 -1553 -1627 -1763 DLR (Oberpfaffenhofen) -16411 -16588 -16767 -16942 DTAG (Darmstadt) -389 -348 -334 -318 GUM (Warszawa) 12 17 12 17 IEN (Torino) 49 45 41 47 IFAG (Wettzell) -3409 -3408 -3400 -3433 IGMA (Buenos Aires) 97 75 73 78 INPL (Jerusalem) -285 -292 -316 -323 IPQ (Monte de Caparica) 5609 5666 5723 5779 JATC (Lintong) -4847 -4861 -4916 -4970 KRIS (Taejon) 85 96 96 107 LDS (Leeds) - - - - MSL (Lower Hutt) - 13028 13217 13400 NAO (Mizusawa) -1844 -1815 -1781 -1757 NIM (Beijing) -2737 -2731 -2742 -2773 NIST (Boulder) -8 -5 -3 -3 NPL (Teddington) 23 23 23 24 NPLI (New-Delhi) 8780 8830 8884 8937 NRC (Ottawa) 50 53 57 66 NRLM (Tsukuba) - - - - OMH (Budapest) 5183 5212 5224 5228 ONBA (Buenos Aires) -59 -61 -51 -58 ONRJ (Rio de Janeiro) 3182 3198 3209 3220 OP (Paris) 8 16 14 9 ORB (Bruxelles) 19 17 13 15 PSB (Singapore) 2261 2275 2284 2306 PTB (Braunschweig) 18 12 6 4 ROA (San Fernando) -77 -68 -69 -60 SCL (Hong Kong) 8 -4 -16 -38 SMU (Bratislava) -3849 -3861 -3866 -3875 SO (Shanghai) - - - - SP (Boras) -227 -213 -201 -172 SU (Moskva) 103 106 107 107 TL (Chung-Li) -125 -134 -130 -137 TP (Praha) 136 139 129 134 UME (Gebze-Kocaeli) -412 -415 -409 -415 USNO (Washington DC)(USNO MC) 4 1 2 4 VSL (Delft) 40 40 43 42 BIPM , T 156 (3) 2 - International Atomic Time TAI and local atomic time scales TA(k). The following table gives the computed values of TAI-TA(k). Date 2000 0h UTC Nov 26 Dec 1 Dec 6 Dec 11 MJD 51874 51879 51884 51889 Laboratory k TAI-TA(k) (Unit is one nanosecond) AMC (Col. Springs) -366604 -366613 -366622 -366629 AUS (Sydney) -104786 -104828 -104919 -105031 CH (Bern) 281 472 663 847 CRL (Tokyo) 138194 138381 138564 138743 CSAO (Lintong) -242 -244 -239 -249 F (Paris) 164179 164202 164224 164249 IEN (Torino) 11487 11436 11405 11291 JATC (Lintong) -11853 -11954 -12052 -12160 KRIS (Taejon) 6089 6092 6085 6083 NIST (Boulder) -45213564 -45213762 -45213960 -45214155 NRC (Ottawa) 27460 27465 27470 27483 PTB (Braunschweig) -360333 -360324 -360314 -360309 SU (Moskva) (1) 27241103 27241104 27241104 27241105 USNO (Washington DC) -34852968 -34853283 -34853598 -34853913 Date 2000 0h UTC Dec 16 Dec 21 Dec 26 Dec 31 MJD 51894 51899 51904 51909 Laboratory k TAI-TA(k) (Unit is one nanosecond) AMC (Col. Springs) -366637 -366652 -366663 -366673 AUS (Sydney) -105140 -105240 -105334 -105437 CH (Bern) 1038 1227 1421 1602 CRL (Tokyo) 138928 139111 139294 139473 CSAO (Lintong) -251 -224 -232 -243 F (Paris) 164272 164293 164314 164334 IEN (Torino) 11190 11117 11113 11060 JATC (Lintong) -12258 -12330 -12470 -12583 KRIS (Taejon) 6075 6082 6075 6086 NIST (Boulder) -45214354 -45214551 -45214749 -45214949 NRC (Ottawa) 27482 27490 27498 27512 PTB (Braunschweig) -360306 -360307 -360308 -360305 SU (Moskva) (1) 27241103 27241106 27241107 27241107 USNO (Washington DC) -34854226 -34854543 -34854856 -34855168 3 - Notes on sections 1 and 2. (1) SU . Listed values are TAI-TA(SU) - 2.80 seconds. BIPM , T 156 (4) 4 - Difference between the normalized frequencies of EAL and TAI. Interval of validity f(EAL)-f(TAI) 2000 Nov. 26 - 2001 Jan. 30 51874-51939 7.100x10**-13 New steering correction foreseen for February and March 2001 2001 Jan. 30 - 2001 Mar. 31 51939-51999 7.090x10**-13 5 - Duration of the TAI scale interval. TAI is a realization of coordinate time TT. The following tables give the fractional deviation d of the scale interval of TAI from that of TT (the SI second on the geoid), i.e. the fractional frequency deviation of TAI with the opposite sign: d = -yTAI. In this section, a frequency over a time interval is defined as the ratio of the end-point phase difference to the duration of the interval. Whenever needed, the instability of EAL should be expressed as the quadratic sum of three components: a white frequency noise 6.0x10**-15 / sqrt(t), a flicker frequency noise 0.6x10**-15, a random walk frequency noise 1.6x10**-16 x sqrt(t), with t in days. The relation between EAL and TAI is given in Circular T and the annual report. In the first table, d is obtained, on the given periods of estimation by comparison of the TAI frequency with that of the given individual primary standards (PFS). In this table uB is the combined uncertainty from systematic effects, Ref(uB) is a reference giving information on the stated value of uB or is the Circular T where this reference was first given, uA is the uncertainty originating in the instability of the PFS, ulink/lab is the uncertainty in the link between the PFS and the clock participating to TAI, ulink/TAI is the uncertainty in the link to TAI, u is the quadratic sum of all four uncertainty values. Standard Period of d uB Ref(uB) uA ul/lab ul/TAI Notes u estimation (10-15)(10-15) (10-15)(10-15) (10-15) (10-15) PTB CSF1 51864-51879 +9.5 1.4 T152 1. 0. 2. (1) 2.6 PTB CS1 51874-51909 +1.2 8. T148 5. 0. 1. (2) 9. PTB CS2 51874-51909 +7.4 12. T148 3. 0. 1. (2) 12. (1) Report 20 December 2000 by PTB (2) Continuously operating as a clock participating into TAI The second table gives the BIPM estimate of d, based on measurements of CRL-O1, NIST-7, NIST-F1, NRLM-4,PTB CS1, PTB CS2, PTB CS3 and PTB CSF1 over the period MJD 51514-51909, taking into account their individual uncertainties and characterizing the instability of EAL as noted above. u is the computed standard uncertainty of d. Period of estimation d u 51874-51909 +6.2x10-15 2.3x10-15 BIPM , T 156 (5) 6 - [UTC-GPS time] and [TAI-GPS time]. [UTC-GPS time] = -13 s + C0, [TAI-GPS time] = 19 s + C0. Daily values of C0 are given in the following table. They are obtained as follows: the GPS data taken at the Paris Observatory, for highest elevation, are first corrected for precise satellite ephemerides and for measured ionospheric delays, and then smoothed to obtain daily values of [UTC(OP)-GPS time] at 0h UTC; daily values of C0 are derived from them using linear interpolation of [UTC-UTC(OP)]. The global uncertainty of daily C0 values is of order 10 ns. In the following table, the standard deviation s characterizes the dispersion of individual measurements, and N is the number of measurements used on a given day for estimation of the corresponding daily C0 value. Date 2000 MJD C0 s s/sqrt(N) 0h UTC (ns) (ns) (ns) Nov 26 51874 2 6 1 Nov 27 51875 2 5 1 Nov 28 51876 -1 7 1 Nov 29 51877 -5 6 1 Nov 30 51878 -8 6 1 Dec 1 51879 -8 8 1 Dec 2 51880 -10 5 1 Dec 3 51881 -10 7 1 Dec 4 51882 -12 7 1 Dec 5 51883 -15 7 1 Dec 6 51884 -20 6 1 Dec 7 51885 -22 8 1 Dec 8 51886 -24 6 1 Dec 9 51887 -25 8 1 Dec 10 51888 -23 6 1 Dec 11 51889 -21 5 1 Dec 12 51890 -17 6 1 Dec 13 51891 -14 8 1 Dec 14 51892 -11 6 1 Dec 15 51893 -10 7 1 Dec 16 51894 -9 6 1 Dec 17 51895 -7 6 1 Dec 18 51896 -7 4 1 Dec 19 51897 -7 6 1 Dec 20 51898 -7 6 1 Dec 21 51899 -5 6 1 Dec 22 51900 -4 6 1 Dec 23 51901 -6 5 1 Dec 24 51902 -7 5 1 Dec 25 51903 -10 5 1 Dec 26 51904 -11 5 1 Dec 27 51905 -11 6 1 Dec 28 51906 -11 4 1 Dec 29 51907 -10 5 1 Dec 30 51908 -10 5 1 Dec 31 51909 -11 5 1 BIPM , T 156 (6) 7 - [UTC-GLONASS time] and [TAI-GLONASS time]. [UTC-GLONASS time] = 0 s + C1, [TAI-GLONASS time] = +32 s + C1. Daily values of C1 are given in the following table. They are obtained as follows: the GLONASS data taken at the NMi Van Swinden Laboratorium, Delft, The Netherlands, for highest elevation, are smoothed to obtain daily values of [UTC(VSL)-GLONASS time] at 0h UTC; daily values of C1 are then derived from them using linear interpolation of [UTC-UTC(VSL)]. The global uncertainty of daily C1 values is of order several hundreds of nanoseconds. In the following table, the standard deviation s characterizes the dispersion of individual measurements, and N is the number of measurements used on a given day for estimation of the corresponding daily C1 value. Date 2000 MJD C1 s s/sqrt(N) 0h UTC (ns) (ns) (ns) Nov 26 51874 -178 20 5 Nov 27 51875 -183 19 6 Nov 28 51876 -182 19 4 Nov 29 51877 -135 24 6 Nov 30 51878 -160 23 7 Dec 1 51879 -195 19 4 Dec 2 51880 -194 21 4 Dec 3 51881 -193 15 3 Dec 4 51882 -175 15 3 Dec 5 51883 -189 30 10 Dec 6 51884 -206 23 6 Dec 7 51885 -193 19 4 Dec 8 51886 -195 15 3 Dec 9 51887 -209 16 4 Dec 10 51888 -205 16 3 Dec 11 51889 -207 17 4 Dec 12 51890 -202 15 3 Dec 13 51891 -217 6 2 Dec 14 51892 -225 25 4 Dec 15 51893 -215 23 4 Dec 16 51894 -190 20 4 Dec 17 51895 -213 10 2 Dec 18 51896 -219 24 5 Dec 19 51897 -214 22 5 Dec 20 51898 -213 15 3 Dec 21 51899 -252 11 6 Dec 22 51900 -275 17 6 Dec 23 51901 -273 24 8 Dec 24 51902 -269 26 6 Dec 25 51903 -290 18 4 Dec 26 51904 -294 21 5 Dec 27 51905 -306 18 4 Dec 28 51906 -321 19 5 Dec 29 51907 -346 28 8 Dec 30 51908 -376 16 3 Dec 31 51909 -369 16 4