Research on Timescale algorithms in Database for TA(PL)

The group of Polish Time Laboratories has been cooperating closely from at least 15 years. From very beginning also Lithuania was participating in this group. The first common initiative was organizing independent Polish Atomic Timescale TA(PL) [8]. In 2004 has started a project to develop Database for Polish Atomic Timescale TA(PL) [5] to automate the process of time-standards comparison and calculate implemented group timescale ensembles algorithms (weighted average algorithm for a group of time-standards). Ensemble algorithms are supposed to be more stable than any of the standard within the group. This very useful feature makes an ensemble a very good stable reference to control and supervise behavior of every standard. In the future it could be also used to steer Polish official realization of international Universal Coordinated Time (UTC) the UTC(PL) maintained by Central Office of Measurement (GUM). The set of ensemble algorithms was primary implemented in Database: original algorithm of TA(PL) based on ALGOS [6], [7] (algorithm developed by International Bureau of Measurements-BIPM), one day-shifted ALGOS version and AT1 [2] (algorithm developed by National Institute of Standard and Technology-NIST). During last years the Time-team of Institute of Telecommunications has implemented in Database a realization of AT2 algorithm developed on the basis of theorem published by NIST. Preliminary results shows that AT2 is more stable than others. The last part of article shows analysis of results of new implemented algorithms and comparison to former implementations.