We wstępie artykułu opisano kwantowo-mechaniczny efekt tunelowy. Wykonano obliczenia strzałki ugięcia mikrobelki krzemowej pod wpływem przyspieszenia. Obliczono też natężenie prądu tunelowego, płynącego przez złącze utworzone między końcem igły o atomowej grubości ostrza zamocowanej na mikrobelce i powierzchnią Przedstawiono projekt czujnika przyspieszenia o wysokiej czułości, w którym zastosowano układy takich złącz połączone szeregowo i równolegle. Przedyskutowano otrzymane wyniki oraz możliwości zastosowania takich czujników przyspieszenia w szczególności jako precyzyjnych grawimetrów.
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The quantum-mechanical tunneling effect is described in introduction of the article. Computation of the bending arrow of the microcantilever undergo acceleration are conducted. A tunneling current intensity flowing in the junction between tip of the needle witch atomic size thickness connected with the microcantilever made of silicone and surface are also executed. The project of the high sensitivity accelerometer based on systems of the junction connected parallel and in series is presented. Obtained results and feasibility of the application of the considered system in accelerometers, especially in precision gravimeters are discussed.
In this paper, a description of the design and operation principle of the double-ring dynamically tuned gravimter is given. This design allows for the gravimeter signal separation from the noise, which makes it possible to increase the measurement accuracy of Earth’s gravitational field anomalies using gravimetric aviation system to 1 mGal.
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The examined area is situated in the Púchov section of the Pieniny Klippen Belt (PKB) in western Slovakia. The main aim of our research was to broaden the present knowledge on geological structure of the PKB and on its tectonic connection to the surrounding regional units using the geophysical methods.The profile gravity measurements consist of two parallel profiles named prof_1 and prof_2 of roughly NNW-SSE direction. The eastern section prof_1 has a length of 6.36 km; the western profile prof_2 is about 3.84 km long. Measurements were carried out at intervals of 20 meters (overall 506 points were gauged) by gravimeters Scintrex CG3 and CG5. The acquire data were processed into the Bouguer gravity anomalies. The software package GM-SYS (Geosoft) was applied for the gravity modelling and the final geological-geophysical sections represent distribution of the lithological members with their specific density parameters (density values were determined by the own laboratory measurements of rock samples collected along the profiles). The density modelling was also based on the results obtained by the geoelectrical exploration (vertical electric sounding and resistivity profiling), new surface geological mapping and borehole interpretation (continuously cored bores MIK-1 and MIK-2). Presented detailed gravity measurements reflect density differences between klippen (rigid limestone blocks) and their mantle (predominant marlstone) and they demonstrate that the primary fold-nappe system of the PKB was destructed by the subsequent deformation, resulting in the formation of the positive flower structure and backthrusting. Summing up, the new density modelling confirmed complex geological structure of the studied area and helped us to better interpret the tectonic evolution of the PKB.
For last two centuries the role of gravity measurements in geodesy was continuously growing with the development of physical geodesy, growing needs for precise geodetic products and progress in technology. A very condensed historical review of gravimetric surveys with their uncertainty characteristics is given in the paper. It starts with single gravity measurements using simple pendulum through the application of reversible pendulum up to four-pendulum apparatus. Superiority of relative gravity survey over absolute gravity survey using pendulum has been highlighted. Further, the development of static spring gravimeters is briefly presented followed by precise ballistic gravimeters that provide more accurate gravity than relative gravity survey and become a valuable tool for geodynamic research. The concept of superconducting gravimeter and its role in geodynamic research is highlighted. Special emphasis is given to the portable free-fall gravimeter A10 designed for field survey. Also the achievements in the direction of developing atomic absolute gravimeters are briefly mentioned. The evolution of the concept and realization of the gravity control is discussed on the background of the progress in gravimetry, paying special attention on its scale and gravity level. It is illustrated with some examples of evolving Polish national gravity control. Finally an attempt to formulate the concept of modern gravity control is presented.
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In 2006 a gravimetric pavilion was installed inside the Geodynamic Laboratory (LG) in Książ. The pavilion was equipped with two pillars intended to serve relative and absolute gravimetric measurements. Installation of measurement platform for absolute gravity measurements inside gravimetric pavilion of LG made it possible to perform four sessions of absolute gravity measurements: two of them in 2007 (June 10-12 and Nov. 21-22), one in 2008 (Apr. 21-22) and one in 2011 (June 19-21). In 2007 the absolute measurements were performed using two FG5 ballistic gravimeters. In April 2007 the measurements were performed by Dr Makinen from Geodetic Institute of Finnish Academy of Science with application of FG5 No. 221 absolute gravimeter. In June 2007 and in the years 2008 and 2011 such gravimetric measurements were performed by the team from Department of Geodesy and Astronomical Geodesy of Warsaw University of Technology using FG5 No. 230 absolute gravimeter. Elaboration of observation sessions from both gravimeters was performed in the Department of Higher Geodesy following the procedures used in constituting of uniform gravimetric system of geodynamic polygons reference. This constituting of gravimetric system comprised inter alia application of identical models of lithospheric tides (global model by Wenzel, 1997) and ocean tides (Schwiderski, 1980) (reduction of absolute measurements with tidal signals). Observations performed during summer of 2007, autumn of 2007, and spring of 2008 and 2011 indicated existence of small changes of absolute gravity of the order of 1 Gal. Maxima of accelerations appear in the spring period, and minima in the autumn period. This effect is connected with the influence of global hydrological factors the annual amplitude of which is ca 1,5 Gal and achieve extreme values in the spring-autumn interval. Very small value of observed amplitude of gravity changes in the period of extreme variability suggests that the observed gravity changes in LG are caused only by global phenomenon. This proves high degree of „independence” of gravimetric measurement base in LG from the local environmental factors such as ground water level variations, ground humidity, impact of snow cover, etc. At this moment the instrumental environment of absolute measurements obtains particular value, especially in the case of the tiltmeters and relative the gravimeter Lacoste&Romberg (LR-648). The relative gravity measurements as performed simultaneously with absolute gravity measurements enable us to determine the local tidal ephemeredes which makes it possible to replace the global tidal modal with ocean tidal model with the more realistic, locally determined tidal parameters (the local tidal ephemeredes).
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The most perspective gravimeters which work in structure of aviation gravimetrical system is gyroscopic. Nevertheless doublerings in comparison with singlerings dynamically adjusted gyroscopes, have advantages, most powerful of which: higher accuracy and speed, small dimensions, high sensivity. In work it is received the equations of movement new dynamically adjusted gravimeter which will enable to investigate it(him) further, to make mathematical modelling, to define static and dynamic errors.
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