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Accurate Establishment of Error Models for the Satellite Gravity Gradiometry Recovery and Requirements Analysis for the Future GOCE Follow-On Mission

Zheng W., Wang Z., Ding Y., Li Z.

Acta Geophysica

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2016

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Vol. 64, no. 3

732--754

EN

Firstly, the new single and combined error models applied to estimate the cumulative geoid height error are efficiently produced by the dominating error sources consisting of the gravity gradient of the satellite-equipped gradiometer and the orbital position of the space-borne GPS/GLONASS receiver using the power spectral principle. At degree 250, the cumulative geoid height error is 1.769 × 10–1 m based on the new combined error model, which preferably accords with a recovery accuracy of 1.760 × 10–1 m from the GOCE-only Earth gravity field model GO_CONS_GCF_2_TIM_R2 released in Germany. Therefore, the new combined error model of the cumulative geoid height is correct and reliable in this study. Secondly, the requirements analysis for the future GOCE Follow-On satellite system is carried out in respect of the preferred design of the matching measurement accuracy of key payloads comprising the gravity gradient and orbital position and the optimal selection of the orbital altitude of the satellite. We recommend the gravity gradient with an accuracy of 10–13-10–15 /s2 , the orbital position with a precision of 1-0.1 cm and the orbital altitude of 200-250 km in the future GOCE Follow-On mission.

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Możliwości zwiększania niezawodności metrologicznej przyrządów pomiarowych z zastosowaniem wzorców miar sterowanych kodowo oraz nowoczesnych technologii informacyjnych

Yatsuk W., Wesełucha Z.

Przegląd Elektrotechniczny

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2010

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R. 86, nr 9

80-83

PL

W ramach istniejących teorii niezawodności metrologicznej istotna jest informacja o intensywności degradacji metrologicznej wszystkich parametrów elementów dyskretnych. Międzynarodowy dokument normalizacyjny ISO 10012:2003 wymaga wprowadzania metod kontroli procesów i przyrządów pomiarowych. W celu zwiększania niezawodności metrologicznej inteligentnych cyfrowych przyrządów pomiarowych uzasadnione i celowe jest zastosowanie w ich konstrukcji metody różnicowej pomiaru wraz z korekcją błędów metodą inwersji komutacyjnej. W pracy opisano model matematyczny procesów korekcji wartości przypadkowego składnika błędu całego przyrządu pomiarowego. Określono warunki realizacji sprawdzania metrologicznego pomiarowych przyrządów cyfrowych w miejscu eksploatacji bez ich demontażu. Sformułowano wymagania dotyczące konstrukcyjno-technologicznej realizacji wzorców miar sterowanych kodowo.

EN

Usually, the metrological intensity of all discrete used components is necessary for whole measuring device metrological reliability determination is analysed in this paper. Extrapolation of the metrological characteristic probable variation is another way for measurement units’ metrological reliability estimation. If it possible the measuring devices higher precision class is the sense of third way of the metrological reliability protection. A lot of experimental results elaboration is necessary for correct metrological reliability characteristics estimation by the both first ways. International standard ISO 10012:2003 recommended both measuring process and measuring device control methods introduction. The measuring devices errors polynomial model analysis is presented in this paper too. For the main additive and accidental parts of measuring units error correction by inverse commutating (flip-flop) method is proposed in this paper. The structural circuits with automatically correction both of the bias voltages and accidental inputs signals are proposed for decreasing of the additive constituent error. The differential measurement method with code control measure using is described in this paper too. The main requirements such as on-chip realization and some destabilization quantity influence corrections is discussed too. The metrological checking at measuring devices working conditions is proposed in this paper too.

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Eksperymentalna weryfikacja modelu błędów sieci neuronowej realizującej odtwarzanie w przetworniku próbkującym

Makowski P.

Prace Naukowe Politechniki Śląskiej. Elektryka

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2008

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z. 1

55-73

PL

Model błędów sieci neuronowej realizującej odtwarzanie w przetworniku próbkującym może być w dużej części budowany przy użyciu badań symulacyjnych. Symulacja pozwala na znaczne ograniczenie czasu oraz kosztów, jakie muszą być w związku z tym poniesione. Celem weryfikacji praktycznej, której rezultaty prezentowane są w artykule, jest potwierdzenie przydatności uzyskiwanych rezultatów badań symulacyjnych do potrzeb opisu właściwości metrologicznych rzeczywistych sieci neuronowych.

EN

An error model of a neural network performing reconstruction in a sampling transducer may be built, in a large part, by using results obtained in a simulation way. The simulation allows to limit the time and costs which must be calculated in this situation. The aim of practical verification, which results are presented in this article, is confirmation of usefulness of the obtained simulation results for the characterisation of the metrological properties of real neural network.

4

System oriented mathematical model of single measurement result

Jakubiec J.

Metrology and Measurement Systems

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2006

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Vol. 13, nr 4

405-419

EN

Measurements in a system are performed automatically by using data acquisition cards typically consisting of an amplifier, a samplelhold circuit and an analog-to-digital converter. The results obtained from these cards are processed by a program. The processing algorithms are often of sophisticated numerical structure and, in this situation, the determination of inaccuracy of the system output data needs building a system error model. The base of the error model construction should be a model of a single measurement result delivered at the output of the card. The paper presents a model which has been obtained on the basis of an analysis of the quantization process consisting in a direct comparison of the measured quantity with a standard of quantum character. In a measuring system the quantization is realized by an AD converter, which measures a sample of a time-varying input quantity. The assumption that the sampling is performed at any moment enables obtaining the model described in probabilistic categories, which may be the basis of the uncertainty calculation of the system output data.

5

Construction of telescope inaccuracy model according to data of satellites laser ranging

Medvedsky M. M., Pap V. O.

Artificial Satellites : Journal of Planetary Geodesy

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2006

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Vol. 41, No. 3

105--114

EN

The method of constructing error model of pointing the telescope to the target is present in the article. It bases on using the angular encoders data (azimuth and elevation). This angles are fixed in time in the satellite laser ranging. The data is presented in the codes of angles (in inside frame) and the moments of time, in which they are fixed. The consistence of procedures and result of received model are presented in article. Also advantages and disadvantages of the new model are considered in comparison with the method of stars observers. The method tested on the 40 passes of the satellites. The model constructing in station “Kyiv-Golosiiv” in 2003 year is used for the comparison.[1]. The accuracy of this model is on the level 15 arcsec.