Autores: Mauro Vieira de Lima, Fernando A. Rodrigues
Abstract: One of the main goals of time and frequency transfer is clock comparison between stations separated by large distances. The comparison allows the monitoring of the clock’s performance, including, for instance its long-term stability in terms of its time scale or frequency. In metrology, the interest in the precision and accuracy of measurements stands out. In applications that are based on time or frequency, synchronism to a universal time scale is a requirement to maintain traceability, security and compatibility with other systems. Therefore, the basis for creating and disseminating a universal time scale is a reliable comparison between the clocks in different stations. TWSTFT is one of the most accurate methods for comparing and synchronizing time scales between remote stations connected by a geostationary satellite, whose clocks are references as time and frequency standards. The TWSTFT system can provide a time uncertainty smaller than one nanosecond and provide time and frequency transfer without the main vulnerabilities of GNSS. This paper presents the TWSTFT technique and the feasibility of using TWSTFT to provide traceability in the Brazilian context.