National Time and Frequency Standard (NTFS)

 

[Home Page] [Home Page - beta version]

______________________________________________________________________

 

     Institution Charged with Responsibility for NTFS

 

Institute of Photonics and Electronics of the Academy of Sciences of the Czech Republic (IPE)

Laboratory of the National Time and Frequency Standard (CMI Associated Laboratory)

 

Appointed by the Czech Office for Standards, Metrology and Testing (COSMT) on May 22, 2002)

 

 

     Organization Structure

 

 

 

     Prediction of UTC

 

Name: UTC(TP), TP denotes Tempus Pragense

Source of UTC(TP): 5071A/001, SN1227 steered to UTC

 

     Cesium Frequency Standards Reported to BIPM via UTC(TP)

 

Operating at IPE:

(1)           5071A/001, SN 0326

(2)           5071A/001, SN 1227

Operating at Telefónica O2:

(3)           5071A/001, SN 0163

(4)           5071A, SN 0154

 

 

     Time Transfer from/to IPE

 

Method: GPS common-view comparisons

GPS Timing Receivers:

(1)          GTR50 (SN 001), dual frequency, multichannel

Antenna: Novatel GPS-702, dual frequency, temperature stabilized

(2)          GTR50 (SN 002), dual frequency, multichannel

Antenna: Novatel GPS-702, dual frequency, temperature stabilized

(3)          AOA TTR-6 (SN 260)

(4)          AOA TTR-6 (SN 412)

 

 GTR50 Specifications, View of GPS antennas for GTR50 receivers:  A ,  B

 

 

     Time Transfer between IPE and Telefónica O₂

 

Method: Transmission via fiber optic links 

Link specifications:

Length: 10.8 km

Wave length: 1300 nm

Standard signals transmitted: 5 MHz from IPE to O₂ (optionally 1 pps), 10 MHz from O₂ to IPE 

Link time stability:  TDEV(τ₀=1s) < 50 ps , seasonal variations:  < 10 ns peak-to-peak   

 

View of the IPE Time Laboratory

 

Interconnection between  IPE and O2 

 

     Short-term Stability Measurement

 

Time Domain

 

Method: Dual-mixer time-difference multiplication

Instrument: Laboratory measurement system with IPE3 DMTDM comparator

Measured frequency: 5 MHz

Basic sampling interval: 0.2 s

Low-pass filter (single pole): f_c = 16 Hz

Background instability:

Frequency:  ADEV(τ=1s) = 6x10^-15

Time:          TDEV(τ₀=0.2s) = 2.7 fs (1.7 fs  flicker PM floor)

     (Tested by two +4 dBm signals power-split from the reference BVA oscillator SN 315).

 

Frequency Domain

 

Method: Phase detection

Instrument: FSS1000E Phase Noise Detector plus SR760 FFT Spectrum Analyzer

Frequency Range: 1 MHz to 1 GHz

Background noise at 5 MHz: L(f=1Hz)= –145dBc/Hz, L(f=100kHz)= –177dBc/Hz

 

Reference Oscillators

 

(1) 5MHz BVA Oscilloquartz 8600-BC5GE (SN 291)

(2) 5MHz BVA Oscilloquartz 8600-BC5GE (SN 315)

Pair flicker FM floor: ADEV= 1x10^-13

 

View of the Laboratory for Stability Measurement

 

 

     Recent TP Data Published by BIPM

 

UTC-UTC(TP)

 

                                 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 2009 January 1, 0h UTC, TAI-UTC = 34 s.

Laboratory k                                         [UTC-UTC(k)]/ns

 

Date 2008/09 0h UTC         DEC 29   JAN  3   JAN  8   JAN 13   JAN 18   JAN 23   JAN 28    Uncertainty/ns

       MJD                   54829    54834    54839    54844    54849    54854    54859     uA    uB    u

TP   (Praha)                  -0.6     -1.8    -10.1    -10.8    -11.1    -10.0    -13.1    0.9   5.1   5.2

Date 2009    0h UTC         JAN 28   FEB  2   FEB  7   FEB 12   FEB 17   FEB 22   FEB 27    Uncertainty/ns

       MJD                   54859    54864    54869    54874    54879    54884    54889     uA    uB    u

TP   (Praha)                 -13.1    -12.4    -15.2    -16.4    -18.3     -9.7     -3.1    0.9   5.1   5.2

 

Monthly Clock Rates

 

                       INTERNATIONAL ATOMIC TIME

 

                       MONTHLY RATES OF TAI-CLOCK

           FOR INTERVALS OF ONE MONTH ENDING AT THE GIVEN DATES

 

        (UNIT IS ns/day , 0.00 DENOTES THAT THE CLOCK WAS NOT USED)

 

     LAB.     CLOCK       54739   54769   54799   54829   54859   54889

     TP      35  326     -58.47  -60.64  -61.90  -61.26  -62.69  -63.09

     TP      35 1227       0.00    0.00    0.00    0.00    0.00   11.04

     TP      36  154      11.00   11.44   11.39   12.47   10.52   10.67

     TP      35  163      20.31   20.08   20.40   19.64   18.56   17.96

 

Relative Clock Weights 

 

 

                RELATIVE WEIGHTS (IN PERCENT) OF THE CLOCKS

           FOR INTERVALS OF ONE MONTH ENDING AT THE GIVEN DATES

 

   LAB.   CLOCK      54739    54769    54799    54829    54859    54889

   TP    35  326     0.011    0.011    0.010    0.011    0.011    0.012

   TP    35 1227     *****    *****    *****    *****    *****    0.000

   TP    36  154     0.206    0.211    0.278    0.252    0.284    0.251

   TP    35  163     0.266    0.257    0.245    0.256    0.231    0.160

 

   ***** Clock in repair

 

___________________________________________________________________________________________

 

Home Page

 

Last updated: March 26, 2009