Time and Frequency Standards

Our division is responsible for the highest level of time and frequency measurements in India and keeping them traceable to the the International Bureau of Weights and Measures (BIPM) using ultraprecise satellite links. In simple words, we maintain the Indian Standard Time (IST). The time keeping by us 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).

Dr. S. S. Rajput
Chief Scientist Head, Time & Frequency Division
Room: 128A, Main Building CSIR-NPL, Dr. K. S. Krishnan Rd.,
New Delhi -110012
Ph: +91 11 4560 8343
Fax: +91 4560 9240

Research Activities:

   Precise Timing Systems

       -Maintenence of Indian Standard Time

       -Dissemination of Time

       -Calibration and Testing

   Microwave Frequency Standards

      -Cesium Fountain I and Cesium Fountain II

      - Rubidium Atomic Clock for Space

   Optical frequency Standard

      -Single trapped Ion Optical Standard(STIOS)


Scientists and Technical Staff:

  1. Dr. S. S. Rajput
  2. Mrs. Arunadhati Chatterjee
  3. Dr. Ashish Agarwal
  4. Dr. Subhasis Panja
  5. Dr. Poonam Arora
  6. Mrs. Pranalee Thorat
  7. Dr. Subhadeep De
  8. Mrs. Suchi Yadav
  9. Mrs. Preeti Kandpal
  10. Mr. Mahavir Prasad Olaniya

Students and Project Fellow:

  1. Mr. Aishik Acharya
  2. Mr. Vattikonda Bharath
  3. Ms. Neha Batra
  4. Mr. Thangjam Jayenta Singh
  5. Mr. Anindya Rastogi

Supporting Staff:

  1. Mr. Rakesh Kaushik
  2. Mr. Amar Singh
  3. Mr. Ved Prakash
  4. Mr. Ram Sajjan
  5. Mr. Prem Chand
  6. Mr. Devender Kumar


Find our photos at: https://plus.google.com/photos/108722323066025213151/albums

Drop your comment at :npli.time.frequency@gmail.com