INRIM Time and Frequency Laboratory: Status and Ongoing Enhancement Activities

Valerio Pettiti, Roberto Costa, Giancarlo Cerretto, Cedric Plantard, and Franco Cordara

Abstract:	INRIM Time and Frequency Laboratory (hereafter indicated as TFL), realizes and makes available to the users the UTC(IT) time scale, the legal time scale for Italy. Generated by means of an active hydrogen maser (AHM) and supported by an ensemble of cesium beam frequency standards, hydrogen masers and cesium atomic fountains, it is synchronized via satellite (GPS and TWSTFT, Two Way Satellite Time and Frequency Transfer) with those generated by other international NMIs (National Metrological Institutes) and it is kept in agreement with the international time scale UTC (Universal Time Coordinated) computed by BIPM. Also, TFL regularly contributes to the realization of the TAI time scale, sending to BIPM the measurement results carried out following protocols defined at the international level. In this paper the status of the TFL is presented, highlighting the wide range of ongoing activities that are carried out in order to enhance its robustness and performances, with the aim to better solve the task of national NMI as well as preparing for providing accurate and reliable services to the European navigation system Galileo. In particular, the automatic measuring and controlling system functions basically to collect essential timing measurements and synchronization data, together with information about the status of all the equipment involved in the measurement processes. In order to improve the current system and to cope with ISO/IEC 17025 standard requirements, a new system called DMS (Data Management System) has been designed, allowing for an efficient integration of data coming from different sources. This system will work associated with a informatics system called FMS (File Management System) that will allow for flexible and robust management of the measurement files to be exchanged within the TFL and with external entities. Beside this and being the core of the laboratory, a new system for the UTC(IT) time scale generation is under design, foreseen to be totally automatic and relying on at least two parallel chains (based on AHM), a switching matrix allowing for commutation among the chains in case of failures/anomalies, and new steering and clock anomaly detection algorithms. Enhancements in the TLF dissemination services will be addressed, as well as the new power supply and informatics systems, together with a system able to send e-mail and SMS (Short Message Service) in case of failures/anomalies affecting the different TFL elements.
Published in:	Proceedings of the 43rd Annual Precise Time and Time Interval Systems and Applications Meeting November 14 - 17, 2011 Hyatt Regency Long Beach Long Beach, California
Pages:	95 - 106
Cite this article:	Pettiti, Valerio, Costa, Roberto, Cerretto, Giancarlo, Plantard, Cedric, Cordara, Franco, "INRIM Time and Frequency Laboratory: Status and Ongoing Enhancement Activities," Proceedings of the 43rd Annual Precise Time and Time Interval Systems and Applications Meeting, Long Beach, California, November 2011, pp. 95-106.
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