Time Transfer Metrology at NPL, NEW Delhi

Abstract

The National Physical Laboratory (NPL), New Delhi has the Statutory responsibility to maintain Time Scale UTC (NPL-I) and disseminate standard time and frequency signal (STFS). These aspects are described in this paper.The UTC (NPL-I) is generated via an ensemble of Cesium Clocks. UTC (NPL-I) is intercompared with UTC's of other international time keeping laboratories by continuous monitoring of VLF signal (16 kHz) from GBR (UK) and by receiving time signals from NNSS Satellites which have on-board clocks. Occasional portable clock calibrations have also been carried out. First accurate UTC (NPL-I) calibration was made in May-June 1979 through a two-way time intercomparison between NPL, India and PTB, Federal Republic of Germany via Satellite Symphonie-I.NPL is disseminating standard time and frequency signals at frequencies 5, 10 & 15 MHz under call sign ATA. In the past several experiments on time transfer via satellite Symphonie, APPLE and INTELSAT IV have been performed by NPL with a view to ultimatel...