Wyniki wyszukiwania - BazTech

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Determination of seabed heights in the area of Polish territorial waters in the official reference system

Rogowski J. B., Galas R., Kłęk M.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2020

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Vol. 14, no. 2

339--342

EN

The determination of the height in the vertical reference frame in force in Poland is based both on national regulations (Council of Ministers Regulation, 2012) and on the resolution adopted by the EUREF subcommittee in Tromsø (Resolution No. 5, EUREF Symposium, 2000). Currently, the PL-KRON86-NH vertical reference frame is in use in Poland – a normal height system referred to a quasi-geoid of the average level of the Baltic Sea determined by the zero level of the mareograph in Kronstadt. According to the Regulation, by the end of 2019, Poland will adopt the PL-EVRF2007-NH vertical reference frame, i.e. a normal height system referred to the zero level of the mareograph in Amsterdam. The authors present a method of determining normal heights of seabed referred to the zero level of the mareograph in Amsterdam for coastal areas of the Baltic Sea. This method uses GNSS measurements, the EGM 2008 model and depth measuring methods typical for underwater mining.

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Development of an autonomous Global Navigation Satellite System ground station and its calibration for monitoring of local ionospheric perturbations

Galas R., Čokrlić M.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2016

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nr 45 (117)

54--59

EN

A state-of-the-art monitoring global navigation satellite system (GNSS) system has been originally designed and developed for various positioning and atmosphere-sensing purposes by the authors and updated to fulfil the challenging requirements for monitoring of ionospheric perturbations. The paper discusses various scientific and technically challenging issues, such as the requirement for an autonomous operating ground GNSS station and how this can be fulfilled. Basic algorithms for monitoring of local ionospheric perturbations with GNSS receivers are described. The algorithms require that inter-frequency hardware biases be known. Although the satellite transmitter biases can be obtain from the IGS services, the user takes responsibility for the estimation of frequency dependent receiver hardware biases and for the control of their variations. The instrumental signal delays are important for timing applications and GNSS monitoring of the ionosphere and are also required for recovering of the integer carrier-phase ambiguities. The paper presents an algorithm for calibration of inter-frequency biases of global positioning system (GPS) receivers and validates the first set of results.

3

An Empirical Model for the Ionospheric Global Electron Content Storm-Time Response

Li S., Galas R., Ewert D., Peng J.

Acta Geophysica

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2016

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Vol. 64, no. 1

253--269

EN

By analyzing the variations of global electron content (GEC) during geomagnetic storm events, the ratio “GEC/GECQT” is found to be closely correlated with geomagnetic Kp index and time weighted Dst index, where GECQT is the quiet time reference value. Moreover, the GEC/GECQT will decrease with the increase of the solar flux F10.7 index. Furthermore, we construct a linear model for storm-time response of GEC. Eighty-two storm events during 1999-2011 were utilized to calculate the model coefficients, and the performance of the model was tested using data of 8 storm events in 2012 by comparing the outputs of the model with the observed GEC values. Results suggest that the model can capture the characteristics of the GEC variation in response to magnetic storms. The component describing the solar activity influence shows a counteracting effect with the geomagnetic activity component; and the influence of Kp index causes an increase of GEC, while the time weighted Dst index causes a decrease of GEC.