Robust Optical Clocks for International Timescales (ROCIT)

The recently concluded collaborative European project "Robust optical clocks for international timescales"(ROCIT) tackled some of the key challenges on the roadmap towards a redefinition of the SI second. This paper gives an overview of progress made on improving the robustness and automation of optical clocks and verifying their uncertainty budgets through coordinated international comparison campaigns. It also presents work on the incorporation of optical clocks into time scales, covering both their use to steer local physical time scales and their use for evaluations of hydrogen masers contributing data for the computation of International Atomic Time (TAI). The overall objective of the project was to bring European optical clocks to the stage where they could be operated routinely as secondary frequency standards, regularly contributing to TAI

Diamicton in Besiekierz (Central Poland) : how to avoid misinterpretation of superposition in Quaternary geology

Diamicton in Biesiekierz (central Poland), whose age and origin has long provoked debate, is located above unquestionable Eemian biogenic deposits documented by palynological and Cladocera analyses. Petrographically, this diamicton shows some similarities to Warthanian till. Lithologically, it shows considerable weathering of the deposit, a possible selection of the component minerals and addition of dispersed biogenic matter. The results obtained so far as well as the palaeomorphological situation indicate that the diamicton is reworked till material, as are sand intercalations within it. Given the organic content of this diamicton, we infer that a long-term agricultural exploitation of its immediate surroundings was the main factor behind colluvial reworking and displacement occurring above the Eemian biogenic deposits in the fossil depression

Fennoscandian indicator erratics in glacial tills of Poland

Erratics analysis is one of the principal methods used to study glacial sediments. Usually, simplified petrography of gravel fraction is employed, whereas more advanced techniques, based on interpreting certain rock types of Fennoscandian provenience, are still rarely used in Poland. This is mainly due to the lack of training in classifying erratic rocks, what in turn is at least partly a consequence of the lack of appropriate Polish language atlases. We are willing to bridge this gap, presenting the 33 descriptions of the indicator rock types found in the Pleistocene sediments in Poland. Most descriptions have been illustrated with colour photographs, showing either the specimens from Poland, or the ones collected during our expeditions to Sweden, Denmark and Finland.We present the most important features, which allow to both identify a sample unambiguously and to tie it to a specific outcrop in Fennoscandia. Additionally, we include the geographic coordinates of the central points of source outcrops, used to define the theoretical pebble centres positio

In-country interlaboratory comparison in time and frequency domain – generator with microprocessor signal simulator of electronic watch stepper motor

W niniejszym artykule przedstawione zostały zagadnienia dot. organizowanych przez Główny Urząd Miar krajowych porównań międzylaboratryjnych w dziedzinie czasu i częstotliwości, w kontekście zastosowania w najnowszym porównaniu z 2011 r. jako wzorca przenośnego: generatora z symulatorem sygnału z silnika krokowego zegara elektronicznego. Podczas analizy wyników tego porównania zauważono istotny wpływ charakterystyk pracy stosowanych przez laboratoria chronokomparatorów na wyniki porównania, co przełożyło się na poprawę sposobu szacowania niepewności wyniku pomiaru przez laboratoria biorące udział w porównaniu i lepsze rozumienie uzyskiwanych wyników pomiaru.This paper presents the issues concerning interlaboratory comparisons in time and frequency domain organized by the Central Office of Measures [5, 6, 7]. A short description of the purpose of such comparisons is presented in the first section. The second section contains description of the previous comparisons with a HS-1000 stopwatch as a portable standard which, however, was not stable long-term enough and was not resistant to influence of outside temperature (Fig. 1). In Section 3, there is presented a comparison of 2011 with a new model of the portable standard – a generator with a microprocessor signal simulator of the electronic watch stepper motor (Fig. 2 and 3) whose internal control system and motor stepper signal simulator were made in GUM. This standard is characterized by small dependence of the relative frequency deviation on changes of the outside temperature and simulates three detuning signals with a frequency of about 1 Hz. The analysis of the comparison results of 2011 (Section 4) was focused on the causes of a relatively large discrepancy between the results obtained by participants and the actual (correct) values of the simulated detuned signals in some cases. It was found that the characteristics of the work of the control instruments (clock testers) were critical and needed to be adequately taken into account in estimation of the measurement uncertainty. This comparison helped the participants to better understand the work of the clock testers and allowed them to verify and improve procedures of evaluation of the measurement results obtained with use of this type of equipment

Krajowe porównanie międzylaboratoryjne generatora z mikroprocesorowym symulatorem sygnału z silnika krokowego zegara elektronicznego

W artykule przedstawiono zagadnienia dotyczące organizowanych przez GUM krajowych porównań międzylaboratoryjnych w dziedzinie czasu i częstotliwości. Opisano zalety zastosowania jako obiektu porównań generatora z symulatorem sygnału z silnika krokowego zegara elektronicznego i zwrócono uwagę na charakterystykę pracy chronokomparatorów

Porównanie transferu czasu metodą GPS CV i metodą dwukierunkową z zastosowaniem włókien światłowodowych

W niniejszym referacie przedstawiono najnowsze wyniki, prowadzonych w GUM we współpracy z TP i AGH, badań nad precyzyjną transmisją czasu przez włókna światłowodowe w oparciu o uruchomione pomiędzy GUM i TP stałe operacyjne łącze światłowodowe z zaimplementowaną dwukierunkową metodą transferu czasu i pozostawioną, jako metodą zapasową, metodą GPS CV. Wykazano, że dwukierunkowa transmisja sygnałów czasu poprzez światłowód może być zastosowana do zdalnej kalibracji i monitorowania opóźnień wewnętrznych satelitarnych systemów do transferu czasu.In this paper there are presented the newest results of investigations carried out at the Central Office of Measures (GUM - Główny Urząd Miar) in cooperation with the Polish Telecom (TP - Telekomunikacja Polska S.A) and AGH University of Science and Technology (AGH - Akademia Górniczo-Hutnicza) on a precise time transfer using optical fibers [4-5]. Since December 2008 the constant operational optical link with implemented two-way time transfer method has been run between GUM and TP (Fig. 2, Section 3). Due to using GPS CV method (Fig. 1, Section 2) as a backup, there is carried out continuous comparison of measurement results obtained from both two method. It allows constant verification of the accuracy of the GPS CV method which is the basic method for time transfer in the case of the remaining time transfer links between GUM and the other institutions participating in continuous national comparisons of atomic time and frequency standards. The obtained metrological characteristics of the two-way time transfer using optical fibers are much better than in the case of GPS CV method (Figs. 3 and 4, Section 4). There was confirmed the unstability of internal delays in GPS CV time transfer systems [10-11], probably due to different types of GPS antennas and types of internal conditioning. The optical method can be used for remote calibration of GPS CV time transfer systems. Such investigations are also very important in context of planning to create an optical fiber net for atomic clock comparisons [6]

Fennoscandian indicator erratics in glacial tills of Poland

Erratics analysis is one of the principal methods used to study glacial sediments. Usually, simplified petrography of gravel fraction is employed, whereas more advanced techniques, based on interpreting certain rock types of Fennoscandian provenience, are still rarely used in Poland. This is mainly due to the lack of training in classifying erratic rocks, what in turn is at least partly a consequence of the lack of appropriate Polish language atlases. We are willing to bridge this gap, presenting the 33 descriptions of the indicator rock types found in the Pleistocene sediments in Poland. Most descriptions have been illustrated with colour photographs, showing either the specimens from Poland, or the ones collected during our expeditions to Sweden, Denmark and Finland.We present the most important features, which allow to both identify a sample unambiguously and to tie it to a specific outcrop in Fennoscandia. Additionally, we include the geographic coordinates of the central points of source outcrops, used to define the theoretical pebble centres position (Lüttig 1958)