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BIPM Time Dept database
<html> <head> <SCRIPT LANGUAGE='javascript' SRC='/webdb/js/hide.js'> </SCRIPT> <br> <META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW" http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <TITLE>BIPM Time Dept database</TITLE> <LINK href="/webdb/css/page.css" rel="stylesheet" type="text/css"> <LINK href="/webdb/css/liste.css" rel="stylesheet" type="text/css"> <LINK href="/webdb/css/gnss.css" rel="stylesheet" type="text/css"> <LINK href="/webdb/css/monmenu.css" rel="stylesheet" type="text/css"> <LINK href="/webdb/css/sitemap.css" rel="stylesheet" type="text/css"> <link rel="icon" href="https://webtai.bipm.org/img/favicon.png" type="image/png" /> <link rel="shortcut icon" href="https://webtai.bipm.org/img/favicon.png" type="image/png" /> </head> <body> <TABLE id=entete border=0> <TR height=90px><TD colspan=6 id='entete' >BIPM Time Department Data Base</TD></TR> <TR> <TD class=monmenu> <ul id=dropdown> <li> <a href=/database/index.html>Participation</a> <ul class=sousmenu> <li> <a href=/database/showlab.html>Laboratories</a> </li> <li> <a href=/database/participant.html>Current status</a> </li> <li> <a href=/database/maps.html>Geographical map</a> </li> <li> <a href=/database/guidelines.html>Rules & guidelines</a> </li> <li> <a href=/database/presentations.html>Tutorials & CBKT</a> </li> <li> <a href=/database/dissemination.html>Dissemination services</a> </li> </ul> </li> </ul> </TD> <TD class=monmenu> <ul id=dropdown> <li> Equipments <ul class=sousmenu> <li> <a href=/database/clocklab.html>Clocks</a> </li> <li> <a href=/database/gnss.html>GNSS</a> </li> <li> <a href=/database/tw.html>TWSTFT</a> </li> <li> <a href=/database/equipment.html>Source of UTC(k)</a> </li> <li> <a href=/database/psfs_access.html>PSFS</a> </li> </ul> </li> </ul> </TD> <TD class=monmenu> <ul id=dropdown> <li><a href=/database/readme_clb.html> Calibrations</a> <ul class=sousmenu> <li> <a href=/database/calid_gnss.html>GNSS status </a> </li> <li> <a href=/database/calib.html>GNSS results</a> </li> <li> <a href=/database/calid_tw.html>TWSTFT status</a> </li> </ul> </li> </ul> </TD> <TD class=monmenu> <ul id=dropdown> <li><a href=/database/readme_clk.html> Resources</a> <ul class=sousmenu> <li> Graphs <ul class=sousmenu3> <li> <a href=/database/canvas.html>UTC-UTC(k)</a> </li> <li> <a href=/database/canvas_gnss.html>UTC and GNSS</a> </li> <li> <a href=/database/show_psfs.html>PSFS contributions</a> </li> <li> <a href=/database/d_plot.html>Fract. deviation <i>d</i></a> </li> </li> </ul> <li> <a href=/database/clock.html>Clock stats & codes</a> </li> <li> <a href=/database/howtoclk.html>Get clock code</a> </li> <li> <a href=/database/timescales.html>Time scales</a> </li> </ul> </li> </ul> </TD> <TD class=monmenu> <ul id=dropdown> <li> Web services <ul class=sousmenu> <li> <a href=/api/>API UTC</a> </li> <li> <a href=/api/ccl-cctf/>API CCL-CCTF</a> </li> <li> <a href=/database/../ftp/pub/tai/>FTP results</a> </li> </ul> </li> </ul> </TD> <TD class=monmenu><ul id=dropdown><li><a href=/database/index.html>Home</a><ul class=sousmenu> <li> <a href=/database/sitemap.html>Site Map</a> </li> <li> <a href=/database/mailing.html>Newsletter</a> </li> <li> <a href="javascript:hidden_email('tai','bipm.org','');">Contact us</a> </li> </ul> </li> </ul> </TD> </TR> </TABLE> <p><H1>International reference time scales (from BIPM) : </H1> <ul><li><a href='/ftp/pub/tai/ttbipm/'>TT(BIPM)</a> : realization of Terrestrial Time TT(BIPM) is a realization of Terrestrial Time as defined by the International Astronomical Union (IAU). <br>It is computed annually by the BIPM, based on a weighted average of the evaluations of the frequency of TAI by the primary and secondary frequency standards. <br>It is mostly used in scientific applications requiring long-term frequency stability and high frequency accuracy.</li></ul></p><p><H1>Time scales relationship (from BIPM) : </H1> <ul><li>Differences between the <a href='/ftp/pub/tai/other-products/ealtai/feal-ftai'>normalized frequencies of EAL and TAI </a>, since the beginning of the steering, in 1977.</li> </ul></p><br><p><H1>Time scales relationship (from IERS) </H1> <ul><li>Differences between UTC and TAI : </li> <ul><li> <a href='https://hpiers.obspm.fr/eoppc/bul/bulc/TimeSteps.history'>Relative frequency offsets and step adjustments</a></li></li> <li><a href='https://hpiers.obspm.fr/eoppc/bul/bulc/UTC-TAI.history'>Relationship between TAI and UTC</a>. </li></ul> <li><a href='https://hpiers.obspm.fr/eoppc/bul/bulc/Leap_Second.dat'>Leap seconds</a></li> </ul></p><br><br> <font color='red'>--- Website disclaimer ---<br> The information contained in this website is for general information purposes only. <br>The BIPM Time Department makes no representations or warranties about the completeness, accuracy and reliability of the information. <br><br></font> <hr><TABLE class='sitemap'> <tr> <td class='sitemap'><a href="/database/index.html" 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