Insertion of LEAP SECOND in the Indian Standard Time
New Delhi 30.12.2016: Council of Scientific & Industrial Research (CSIR) -National Physical Laboratory (CSIR-NPL) is the custodian of Indian Standard Time (IST) and has the responsibility for realization, establishment, maintenance and dissemination of IST through an act of Parliament.A “Leap Second” is added every now and then to Coordinated Universal Time (UTC) in order to synchronize clocks worldwide with the Earth’s ever slowing rotation. UTC consists of a time scale that combines the output of more than 300 highly precise Atomic clocks worldwide, including the one at CSIR-NPL. Atomic clocks are very accurate and are stable within 1 second over a period of millions of years. On the other hand, the Astronomical Time known as Universal Time (UT1) refers to the Earth’s rotation around its own axis and determines the length of a day. However, the Earth’s rotation around its own axis is not regular, as sometimes it speeds up and sometimes it slows down, due to various factors including the moon’s gravitational Earth-braking forces that often results in ocean tides. As a result, Astronomical Time (UT1) gradually falls out of synch with Atomic time (UTC), and as and when the difference between UTC and UT1 approaches 0.9 seconds, a “Leap Second” is added to UTC through Atomic clocks worldwide.Since 1972, 36 “Leap Seconds” have been added at intervals varying from six months to seven years. 37th “Leap Second” will be added to UTC at the midnight of December 31, 2016 in the countries within this time zone. However, countries in other time zones will have “Leap Second” inserted according to their longitude. As the “Leap Second” is added simultaneously all over the world at UTC 23:59:59 on December 31, 2016, implying that in India the “Leap Second” will be inserted at IST 05:29:59 on January 1, 2017 (IST being five hours and thirty minutes ahead of UTC). In order to follow IST, the clocks need to be adjusted after the insertion of “Leap Second”. Those utilizing CSIR-NPL time dissemination services (NTP, Teleclock etc.) need not worry as they will receive the corrected time post the insertion of “Leap Second”. The “Leap Second” adjustment is not so relevant for normal everyday life; however this shift is critical for applications requiring of time accuracies in the nanosecond e.g. astronomy, satellite navigation, communication networks etc. A “Leap Second” explanatory meeting will be held on December 31, 2016 at 23:30 Hours at the Main Building Reception area of the CSIR-National Physical Laboratory.
The main objective of this division is to strengthen and encourage the overall development in the field of science and technology for the country. The main responsibility is the realization, establishment, custody, maintenance, dissemination and upgradation of the national standards for Time & Frequency and Electrical & Electronics parameters.
The Time & Frequency Metrology Section is responsible for the highest level of time and frequency measurements in India using ultraprecise satellite links. In simple words, CSIR-NPL maintains the Indian Standard Time (IST ). The time keeping by NPL is based on a bank of Cesium (Cs) atomic clocks and a Hydrogen maser. These clocks are so accurate that they would lose or gain one second in about three lakh years. The traceability of our time scale with BIPM is at the level of few nano-seconds (ns). In addition, we carry out research and development on primary atomic clocks. Our first Cs fountain clock, with an accuracy of a few parts in 10-15 , became operational in 2011. A second Cs Fountain is under development (project NOVOCEF). Recently, we have started developing a more accurate clock (≈10-17 ) at optical wavelengths based on a single trapped Ytterbium ion (project STIOS).
The Division also maintains the primary standards like Josephson Voltage Standards and Quantum Hall Resistance Standards. A dedicated group is working for establishing the Device Fabrication and Characterization for Quantum Metrology.
The Division is also providing various apex level calibration services in Time & Frequency, Electrical and Electronic parameters to the industry & user organizations of the country and provides educational training on industrial metrology to support the economic growth. The various Electrical & Electronic parameters are LF, HF Impedance and DC Metrology, LF, HF Voltage, Current & Microwave Metrology, AC High Voltage & Current Metrology and AC Power & Energy Metrology.
|Scientist Incharge||Dr. V. N. Ojha|
|Chief Scientist & Head|
|Time & Frequency and Electrical & Electronics Metrology Division|
|Phone: +91-11-45608290 / 45608593|
|Address :||Head, Time & Frequency and Electrical & Electronics Metrology Division|
|Room No. 126|
|National Physical Laboratory|
|Dr. K. S. Krishnan Marg|
|New Delhi – 110012, INDIA.|
|Sub Division||Head||E-mail ID|
|Time and Frequency Metrology Section||Dr. V. N. Ojhafirstname.lastname@example.org|
|LF, HF Impedance and DC Metrology Section||Mr. Thomas Johnemail@example.com|
|LF, HF Voltage, Current & Microwave Metrology Section||Mr. P. S. Negifirstname.lastname@example.org|
|AC High Voltage & Current Metrology Section||Mr. M. A. Ansariemail@example.com|
|AC Power & Energy Metrology Section||Mr. J. C. Biswasfirstname.lastname@example.org|
|Quantum Current Metrology Section||Dr. V. P. S. Awanaemail@example.com|
|Quantum Hall Resistance Metrology Section||Dr. H. K. Singhfirstname.lastname@example.org|
|Device Fabrication and Characterization Group for Quantum Metrology Section||Dr. V. N. Ojhaemail@example.com|