CIRCULAR T 247 ISSN 1143-1393 2008 AUGUST 08, 12h UTC BUREAU INTERNATIONAL DES POIDS ET MESURES ORGANISATION INTERGOUVERNEMENTALE DE LA CONVENTION DU METRE PAVILLON DE BRETEUIL F-92312 SEVRES CEDEX TEL. +33 1 45 07 70 70 FAX. +33 1 45 34 20 21 tai@bipm.org 1 - Coordinated Universal Time UTC and its local realizations UTC(k). Computed values of [UTC-UTC(k)] and uncertainties valid for the period of this Circular. From 2006 January 1, 0h UTC, TAI-UTC = 33 s. From 2009 January 1, 0h UTC, TAI-UTC = 34 s. Date 2008 0h UTC JUN 27 JUL 2 JUL 7 JUL 12 JUL 17 JUL 22 JUL 27 Uncertainty/ns Notes MJD 54644 54649 54654 54659 54664 54669 54674 uA uB u Laboratory k [UTC-UTC(k)]/ns AOS (Borowiec) 20.1 18.7 16.6 14.6 14.0 11.2 8.3 0.6 5.1 5.1 APL (Laurel) -4.6 -4.1 -4.5 -14.2 -18.7 -4.2 -6.7 1.5 5.0 5.3 AUS (Sydney) 202.4 209.1 204.8 216.3 221.0 221.0 228.3 1.5 5.1 5.3 BEV (Wien) 15.9 17.9 22.5 30.4 38.4 42.2 41.8 1.5 2.2 2.7 BIM (Sofiya) -6515.7 -6537.9 -6547.8 -6544.3 -6566.1 -6572.1 -6587.6 2.0 7.1 7.3 BIRM (Beijing) -5552.2 -5589.7 -5616.6 -5650.5 -5680.5 -5721.1 -5755.7 2.0 20.0 20.1 BY (Minsk) 279.7 152.1 159.0 179.3 200.1 230.9 266.6 7.0 20.0 21.2 CAO (Cagliari) -2067.0 -2069.3 -2091.7 -2097.8 -2121.5 -2112.3 -2139.4 1.5 7.0 7.2 CH (Bern) -5.2 -1.6 -1.0 0.3 4.1 3.9 -0.1 0.6 1.4 1.5 CNM (Queretaro) 15.9 -1.7 -1.3 1.3 -1.5 -7.5 -12.2 2.5 5.1 5.6 CNMP (Panama) 273.8 295.0 301.4 303.3 308.3 300.4 305.9 3.0 5.1 5.9 DLR (Oberpfaffenhofen) -2.4 -6.7 -4.4 -1.4 0.8 -4.1 -1.8 0.7 5.1 5.1 DTAG (Frankfurt/M) 60.9 57.7 45.8 52.3 70.3 78.9 75.5 4.0 10.0 10.8 EIM (Thessaloniki) 11.0 - - - - - - - - - HKO (Hong Kong) -44.6 -49.8 -53.2 -53.8 -49.6 -57.2 -60.1 2.5 5.1 5.7 IFAG (Wettzell) -213.0 -215.7 -229.9 -227.7 -220.6 -214.9 -213.3 2.5 5.1 5.7 IGMA (Buenos Aires) - - - - - - - - - - INPL (Jerusalem) - - - - - - - - - - IT (Torino) 19.8 17.8 17.0 14.5 16.4 13.5 10.8 0.5 1.4 1.5 JATC (Lintong) 12.3 15.8 16.7 14.0 14.3 14.6 14.6 1.4 4.8 5.0 JV (Kjeller) 9465.5 9600.9 9797.7 9932.9 10090.9 10235.9 10379.5 5.0 20.0 20.6 KIM (Serpong-Tangerang) -238.7 -241.4 -237.9 -223.4 -220.8 -233.3 -236.4 3.0 20.0 20.2 KRIS (Daejeon) 11.8 5.9 6.8 3.5 7.8 2.4 -5.5 0.7 5.0 5.1 LDS (Leeds) - - - - - - - - - - LT (Vilnius) 404.9 402.6 404.8 422.0 421.9 427.2 425.0 1.5 5.1 5.3 LV (Riga) 1761.0 1784.5 1801.4 1824.5 1848.4 1873.4 1892.6 2.0 7.1 7.4 MIKE (Espoo) -114.5 -113.3 -120.2 -116.4 -115.8 -120.7 -125.2 5.0 19.9 20.5 MKEH (Budapest) -6995.4 -7196.5 -7405.4 -7603.1 -7805.8 -8016.2 -8220.7 2.5 20.0 20.2 MSL (Lower Hutt) -277.4 -306.8 -350.6 -381.9 -387.7 -402.2 -420.8 1.0 20.0 20.0 NAO (Mizusawa) -44.1 - - - - - - - - - Date 2008 0h UTC JUN 27 JUL 2 JUL 7 JUL 12 JUL 17 JUL 22 JUL 27 Uncertainty/ns Notes MJD 54644 54649 54654 54659 54664 54669 54674 uA uB u Laboratory k [UTC-UTC(k)]/ns NICT (Tokyo) 20.1 21.7 21.8 23.3 14.5 11.2 10.3 0.5 4.5 4.6 NIM (Beijing) 41.9 43.4 50.4 50.7 60.4 62.3 54.3 1.5 20.0 20.1 NIMB (Bucharest) -238.1 -238.0 -242.1 -221.5 -203.1 -200.2 -214.0 2.0 20.0 20.1 NIMT (Bangkok) 270.7 338.7 400.5 463.5 492.1 483.1 473.3 1.0 20.0 20.1 NIS (Cairo) 31.6 30.4 24.1 23.2 28.4 23.9 19.9 1.5 7.1 7.2 NIST (Boulder) 3.1 3.9 3.3 4.1 4.9 3.5 3.0 0.5 4.8 4.8 NMIJ (Tsukuba) 29.6 24.0 18.4 23.4 25.4 18.3 11.1 0.7 5.0 5.1 NMLS (Sepang) -89.9 -91.1 -86.7 -83.2 -90.7 -103.7 -105.6 2.0 20.0 20.1 NPL (Teddington) -19.4 -19.4 -14.0 -22.6 -17.1 -13.5 -12.8 1.5 5.0 5.2 NPLI (New-Delhi) -4.9 -6.1 -11.5 -18.8 -26.9 -35.4 -34.9 2.5 7.1 7.5 NRC (Ottawa) 40.0 38.5 45.0 56.2 62.3 64.3 64.6 0.7 5.0 5.1 NRL (Washington DC) 8.8 9.1 6.3 6.9 9.2 7.7 5.7 0.7 5.1 5.1 NTSC (Lintong) 1.1 5.4 2.1 6.5 10.0 12.9 15.2 1.4 4.7 4.9 ONBA (Buenos Aires) -1062.6 -1065.6 -1082.9 -1096.7 -1112.4 -1121.0 -1139.3 2.5 5.1 5.7 ONRJ (Rio de Janeiro) -5.6 -4.4 -5.3 -15.0 -4.9 -14.8 -5.5 3.9 19.5 19.9 OP (Paris) -28.8 -24.7 -28.6 -28.6 -26.1 -17.0 -16.0 0.5 1.4 1.5 ORB (Bruxelles) -37.0 -35.8 -37.2 -32.8 -28.5 -28.5 -27.1 0.7 5.1 5.2 PL (Warszawa) 16.0 7.6 6.3 13.2 17.9 20.4 27.2 1.5 4.9 5.1 PTB (Braunschweig) 46.9 49.2 51.3 48.9 53.0 53.0 48.6 0.2 1.0 1.1 ROA (San Fernando) 103.1 97.6 95.0 103.2 102.4 101.1 101.7 0.7 5.0 5.1 SCL (Hong Kong) -21.8 -34.1 -29.7 -34.9 -29.7 -22.3 -27.7 3.0 9.9 10.4 SG (Singapore) -13.7 -12.5 -12.9 7.2 -22.8 0.2 13.8 3.0 5.1 5.9 (1) SIQ (Ljubljana) -19.5 -26.1 -22.1 -5.6 -5.1 7.2 35.7 5.0 20.0 20.6 SMU (Bratislava) 12.3 32.8 45.6 52.9 64.1 69.5 69.8 5.0 20.0 20.6 SP (Boras) 31.8 32.2 31.2 32.4 35.6 37.0 40.9 0.5 1.4 1.5 SU (Moskva) 4.3 1.7 -3.4 -5.1 -3.5 -3.9 -5.3 3.0 5.1 5.9 TCC (Concepcion) -9171.3 -9214.6 -9213.3 -9253.3 -9307.6 -9322.7 -9339.1 1.5 20.0 20.1 TL (Chung-Li) 15.1 11.4 9.6 12.0 13.1 11.6 7.7 0.7 4.8 4.9 TP (Praha) 50.0 49.2 53.3 60.6 65.1 64.0 57.2 0.9 5.1 5.2 UA (Kharkov) -32.0 -57.1 -67.3 -93.3 -98.0 -95.5 -89.3 2.5 6.1 6.6 UME (Gebze-Kocaeli) 170.6 179.2 183.1 181.0 181.7 189.0 185.5 1.5 7.0 7.2 USNO (Washington DC) 7.4 5.3 3.7 2.9 5.0 1.9 -0.3 0.4 1.3 1.3 VMI (Ha Noi) -105.5 -113.6 -111.2 -100.7 -91.2 -90.7 -88.2 1.0 20.0 20.0 VSL (Delft) 77.3 81.8 91.1 105.6 123.5 87.3 56.7 0.5 1.4 1.5 ZA (Pretoria) - - - - - - - - - - ZMDM (Belgrade) 3298.8 3332.5 3352.3 3385.3 3417.6 3438.2 3465.0 2.0 7.1 7.4 - Note on section 1: (1) SG : Change of master clock on MJD 54654. 2 - International Atomic Time TAI and Local atomic time scales TA(k). Computed values of [TAI-TA(k)]. Date 2008 0h UTC JUN 27 JUL 2 JUL 7 JUL 12 JUL 17 JUL 22 JUL 27 MJD 54644 54649 54654 54659 54664 54669 54674 Laboratory k [TAI-TA(k)]/ns CH (Bern) 52559.3 52526.8 52494.9 52462.2 52431.9 52395.9 52361.8 F (Paris) 168207.4 168206.1 168202.4 168203.0 168199.4 168197.9 168195.1 IT (Torino) 73591.5 73713.9 73843.4 73974.6 74107.8 74239.4 74371.3 JATC (Lintong) -44526.3 -44550.8 -44578.2 -44602.5 -44627.9 -44654.1 -44678.6 KRIS (Daejeon) 23381.8 23454.5 23533.3 23608.2 23690.5 23763.8 23834.5 NICT (Tokyo) 83.1 87.1 87.5 89.4 85.3 86.9 89.6 NIST (Boulder) -45322212.4 -45322404.5 -45322597.1 -45322788.2 -45322978.9 -45323171.8 -45323363.8 NRC (Ottawa) 31409.8 31421.6 31440.8 31460.0 31484.3 31501.2 31521.9 NTSC (Lintong) 6745.2 6772.9 6798.0 6826.3 6856.3 6880.7 6911.6 ONRJ (Rio de Janeiro -2907.6 -2929.5 -2957.4 -2988.3 -3012.1 -3040.6 -3065.8 PL (Warszawa) -4762.1 -4773.1 -4781.4 -4784.5 -4793.3 -4800.4 -4807.3 PTB (Braunschweig) -357207.9 -357198.3 -357188.7 -357183.6 -357172.0 -357164.6 -357161.6 SU (Moskva) 27247779.9 27247849.1 27247917.0 27247987.0 27248059.0 27248129.0 27248199.3 (1) TL (Chung-Li) 546.0 542.5 536.4 532.3 529.0 520.9 511.4 USNO (Washington DC) -35023461.9 -35023763.0 -35024064.5 -35024367.7 -35024667.2 -35024970.3 -35025272.9 - Note on section 2: (1) SU : Listed values are TAI-TA(SU) - 2.80 seconds. 3 - Difference between the normalized frequencies of EAL (free atomic time scale) and TAI. Interval of validity f(EAL)-f(TAI) Steering correction 54644 - 54674 6.753x10**-13 (2008 JUN 27 - 2008 JUL 27) New correction 54674 - 54709 6.750x10**-13 (2008 JUL 27 - 2008 AUG 31) New correction foreseen 54709 - 54739 6.747x10**-13 (2008 AUG 31 - 2008 SEP 30) 4 - 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 with t in days: (1) a white frequency noise of 3.0x10**-15 / sqrt(t), (2) a flicker frequency noise of 0.5x10**-15 and (3) a random walk frequency noise of 1.0x10**-16 x sqrt(t). The relation between EAL and TAI is given in Circular T and the BIPM Annual Report on Time Activities. 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 Frequency Standards (PFS). In this table: uA is the uncertainty originating in the instability of the PFS, 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, ul/lab is the uncertainty in the link between the PFS and the clock participating to TAI, including the uncertainty due to the dead-time, ul/TAI is the uncertainty in the link to TAI, u is the quadratic sum of all four uncertainty values. All values are expressed in 10**-15. Standard Period of d uA uB Ref(uB) ul/Lab ul/Tai u Note Estimation PTB-CS1 54644 54674 -5.7 5.0 8.0 T148 0.0 0.1 9.4 (1) PTB-CS2 54644 54674 -1.1 3.0 12.0 T148 0.0 0.1 12.4 (1) SYRTE-FO1 54644 54669 2.5 0.3 0.4 T227 0.1 0.4 0.7 (2) SYRTE-FO2 54644 54674 3.9 0.2 0.4 T227 0.1 0.3 0.6 (2) SYRTE-JPO 54644 54674 2.5 0.5 6.3 T160 0.3 0.3 6.3 (3) PTB-CSF1 54644 54669 6.7 0.1 0.9 T162 0.0 0.2 0.9 (4) IT-CSF1 54649 54669 4.5 0.9 0.5 T233 0.2 0.5 1.1 (5) Notes: (1) Continuously operating as a clock participating to TAI. (2) Report 1 AUG 2008 by LNE-SYRTE. (3) Report 4 AUG 2008 by LNE-SYRTE. (4) Report 1 AUG 2008 by PTB. (5) Report 24 JUL 2008 by INRIM. The second table gives the BIPM estimate of d, based on all available PFS measurements over the period MJD 54284-54674, 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 54644-54674 3.8x10**-15 0.4x10**-15 (2008 JUN 27 - 2008 JUL 27) 5 - Relations of UTC and TAI with GPS time and GLONASS time. [UTC-GPS time] = -14 s + C0, [TAI-GPS time] = 19 s + C0, global uncertainty is of order 10 ns. [UTC-GLONASS time] = 0 s + C1, [TAI-GLONASS time] = 33 s + C1, global uncertainty is of order hundreds ns. The C0 values provide a realization of GPS time, as obtained using the values [UTC-UTC(OP)] and the GPS data taken at the Paris Observatory, corrected for IGS precise orbits, clocks and ionosphere maps. The C1 values provide a realization of GLONASS time, as obtained using the values [UTC-UTC(AOS)] and the GLONASS data taken at the Astrogeodynamical Observatory Borowiec (AOS). N0 and N1 are the numbers of measurements, when N0 or N1 is 0, the corresponding values of C0 or C1 are interpolated. The standard deviations S0 and S1 characterize the dispersion of individual measurements. The actual uncertainty of user's access to GPS and GLONASS times may differ from these values. For this circular, S0 = 2.6 ns, S1 = 12.6 ns Date 2008 0h UTC MJD C0/ns N0 C1/ns N1 JUN 27 54644 -0.2 45 -593.2 81 JUN 28 54645 -2.4 46 -584.7 74 JUN 29 54646 -4.6 46 -581.0 62 JUN 30 54647 -3.4 45 -583.1 22 JUL 1 54648 -1.9 42 -578.0 68 JUL 2 54649 0.8 46 -577.7 73 JUL 3 54650 0.7 47 -573.2 78 JUL 4 54651 -0.5 43 -563.0 75 JUL 5 54652 1.4 42 -557.2 73 JUL 6 54653 -0.2 46 -559.4 66 JUL 7 54654 -2.3 46 -559.8 62 JUL 8 54655 -0.9 46 -554.6 70 JUL 9 54656 1.3 46 -549.1 76 JUL 10 54657 0.4 45 -545.4 79 JUL 11 54658 2.8 45 -542.9 74 JUL 12 54659 0.7 45 -543.1 78 JUL 13 54660 0.4 46 -538.9 82 JUL 14 54661 -1.0 47 -533.5 70 JUL 15 54662 0.1 47 -529.6 79 JUL 16 54663 1.3 47 -523.7 75 JUL 17 54664 1.1 46 -518.9 78 JUL 18 54665 1.0 47 -519.4 67 JUL 19 54666 0.1 47 -519.4 79 JUL 20 54667 -0.1 47 -514.0 79 JUL 21 54668 0.1 43 -514.7 80 JUL 22 54669 -3.0 46 -508.4 74 JUL 23 54670 -5.6 48 -495.6 69 JUL 24 54671 -6.9 47 -488.4 58 JUL 25 54672 -6.5 45 -489.0 72 JUL 26 54673 -3.9 47 -488.8 75 JUL 27 54674 -4.4 46 -485.8 83 6 - Time links used for the computation of TAI and their uncertainties. The time links used in the elaboration of this Circular T are listed in this section. The technique for the link is indicated as follows: GPS SC for GPS all-in-view single-channel C/A data; GPS MC for GPS all-in-view multi-channel C/A data; GPS P3 for GPS all-in-view multi-channel dual-frequency P code data; GPS PPP for GPS Precise Point Positioning technique; GPS GT for 'GPS time' observations; INT LK for internal cable link and TWSTFT for two-way satellite time and frequency transfer data. For each link, the following uncertainties are provided: uA is the statistical uncertainty evaluated by taking into account the level of phase noise in the raw data, the interpolation interval between data points and the effects with typical duration between 5 and 30 days. uB is the estimated uncertainty on the calibration. The calibration type of the link is indicated as: GPS EC for GPS equipment calibration; TW EC for two-way equipment calibration; LC (technique) for a link calibrated using 'technique'; BC (technique) for a link calibrated using 'technique' to transfer a past equipment calibration through a discontinuity of link operation. DIC is used for direct internal calibration. The calibration dates indicate: the most recent calibration results for the two laboratories in the case of EC and the most recent calibration of the link in the case of LC and BC, NA stands for not available, in this case estimated values are provided Link Type uA/ns uB/ns Calibration Type Calibration Dates AOS /PTB TWSTFT 0.5 5.0 BC(GPS MC) 2008 May APL /PTB GPS MC 1.5 5.0 GPS EC/GPS EC 2003 Dec/2004 Jul AUS /PTB GPS MC 1.5 5.0 GPS EC/GPS EC 2004 Nov/2004 Jul BEV /PTB GPS MC 1.5 2.0 BC(TWSTFT) 2008 Jan BIM /PTB GPS MC 2.0 7.0 GPS EC/GPS EC 2007 Nov BIRM/PTB GPS MC 2.0 20.0 NA /GPS EC NA /2004 Jul BY /PTB GPS SC 7.0 20.0 NA /GPS EC NA /2004 Jul CAO /PTB GPS MC 1.5 7.0 GPS EC/GPS EC 2004 Nov/2004 Jul CH /PTB TWSTFT 0.5 1.0 BC(GPS PPP) 2006 Jun CNM /PTB GPS MC 2.5 5.0 BC(GPS SC) 2008 May CNMP/PTB GPS MC 3.0 5.0 GPS EC/GPS EC 2004 May/2004 Jul DLR /PTB GPS P3 0.7 5.0 GPS EC/GPS EC 2007 Feb/2004 Aug DTAG/PTB GPS MC 4.0 10.0 GPS EC/GPS EC 1998 May/2004 Jul EIM /PTB GPS MC 3.0 20.0 NA /GPS EC NA /2003 Aug HKO /PTB GPS MC 2.5 5.0 GPS EC/GPS EC 2004 Sep/2004 Jul IFAG/PTB GPS SC 2.5 5.0 GPS EC/GPS EC 2003 Jun/2004 Jul IGMA/PTB NA INPL/PTB NA IT /PTB TWSTFT 0.5 1.0 BC(TWSTFT) 2006 Mar JATC/NTSC INT LK 0.2 1.0 DIC /2006 Sep Link Type uA/ns uB/ns Calibration Type Calibration Dates JV /PTB GPS GT 5.0 20.0 NA /GPS EC NA /2003 Aug KIM /PTB GPS MC 3.0 20.0 NA /GPS EC NA /2004 Jul KRIS/PTB GPS P3 0.7 5.0 GPS EC/GPS EC 2005 Aug/2004 Aug LDS /PTB NA LT /PTB GPS MC 1.5 5.0 GPS EC/GPS EC 2001 Nov/2004 Jul LV /PTB GPS MC 2.0 7.0 GPS EC/GPS EC 2006 Feb/2004 Jul MIKE/PTB GPS MC 5.0 20.0 NA /GPS EC NA /2004 Jul MKEH/PTB GPS SC 2.5 20.0 NA /GPS EC NA /2004 Jul MSL /PTB GPS P3 1.0 20.0 NA /GPS EC NA /2004 Aug NAO /PTB GPS SC 3.0 20.0 NA /GPS EC NA /2004 Jul NICT/PTB TWSTFT 0.5 5.0 BC(GPS P3) 2007 Mar NIM /PTB GPS MC 1.5 20.0 NA /GPS EC NA /2004 Jul NIMB/PTB GPS MC 2.0 20.0 NA /GPS EC NA /2004 Jul NIMT/PTB GPS P3 1.0 20.0 NA /GPS EC NA /2004 Aug NIS /PTB GPS MC 1.5 7.0 GPS EC/GPS EC 2005 May/2004 Jul NIST/PTB TWSTFT 0.5 5.0 BC(GPS EC) 2005 May NMIJ/PTB GPS P3 0.7 5.0 GPS EC/GPS EC 2002 Apr/2004 Aug NMLS/PTB GPS MC 2.0 20.0 NA /GPS EC NA /2004 Jul NPL /PTB GPS MC 1.5 5.0 GPS EC/GPS EC 2002 Jun/2004 Jul NPLI/PTB GPS MC 2.5 7.0 GPS EC/GPS EC 2005 Jul/2004 Jul NRC /PTB GPS P3 0.7 5.0 GPS EC/GPS EC 2003 Nov/2004 Aug NRL /PTB GPS P3 0.7 5.0 GPS EC/GPS EC 2002 May/2004 Aug NTSC/PTB GPS MC 1.5 5.0 GPS EC/GPS EC 2004 Sep/2004 Jul ONBA/PTB GPS MC 2.5 5.0 GPS EC/GPS EC 2004 Jul/2004 Jul ONRJ/PTB GPS MC 4.0 20.0 NA /GPS EC NA /2004 Jul OP /PTB TWSTFT 0.5 1.0 BC(TWSTFT) 2006 Mar ORB /PTB GPS P3 0.7 5.0 GPS EC/GPS EC 2003 Jul/2004 Aug PL /PTB GPS MC 1.5 5.0 GPS EC/GPS EC 2001 Oct/2004 Jul ROA /PTB TWSTFT 0.7 5.0 BC(GPS PPP) 2005 May SCL /PTB GPS MC 3.0 10.0 LC(GPS SC) 1993 May SG /PTB GPS MC 3.0 5.0 GPS EC/GPS EC 2004 Nov/2004 Jul SIQ /PTB GPS SC 5.0 20.0 NA /GPS EC NA /2003 Aug SMU /PTB GPS SC 5.0 20.0 NA /GPS EC NA /2004 Jul SP /PTB TWSTFT 0.5 1.0 BC(GPS PPP) 2006 Mar SU /PTB GPS SC 3.0 5.0 GPS EC/GPS EC 2003 Apr/2004 Jul TCC /PTB GPS P3 1.5 20.0 NA /GPS EC NA /2004 Aug TL /PTB GPS P3 0.7 5.0 GPS EC/GPS EC 2005 May/2004 Aug TP /PTB GPS P3 0.9 5.0 LC(GPS SC) 2004 Jul UA /PTB GPS MC 2.5 6.0 GPS EC/GPS EC 2006 Jun/2004 Jul UME /PTB GPS MC 1.5 7.0 GPS EC/GPS EC 2005 Dec/2004 Jul USNO/PTB TWSTFT 0.5 1.1 BC(TW X-Band) 2005 May VMI /PTB GPS P3 1.0 20.0 NA /GPS EC NA /2004 Aug VSL /PTB TWSTFT 0.5 1.0 BC(GPS PPP) 2006 Mar ZA /PTB NA ZMDM/PTB GPS MC 2.0 7.0 GPS EC/GPS EC 2005 Mar/2004 Jul