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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Precise Velocity and Acceleration Determination Using a Standalone GPS Receiver in Real Time

Zhang, Jianjun, j3029709.zhang@gmail.com January 2006 (has links)
Precise velocity and acceleration information is required for many real time applications. A standalone GPS receiver can be used to derive such information; however, there are many unsolved problems in this regard. This thesis establishes the theoretical basis for precise velocity and acceleration determination using a standalone GPS receiver in real time. An intensive investigation has been conducted into the Doppler effect in GPS. A highly accurate Doppler shift one-way observation equation is developed based on a comprehensive error analysis of each contributing factor including relativistic effects. Various error mitigation/elimination methods have been developed to improve the measurement accuracy of both the Doppler and Doppler-rate. Algorithms and formulae are presented to obtain real-time satellite velocity and acceleration in the ECEF system from the broadcast ephemeris. Low order IIR differentiators are designed to derive Doppler and Doppler-rate measurements from the raw GPS data for real-time applications. Abnormalities and their corresponding treatments in real-time operations are also discussed. In addition to the velocity and acceleration determination, this thesis offers a good tool for GPS measurement modelling and for design of interpolators, differentiators, as well as Kalman filters. The relativistic terms presented by this thesis suggest that it is possible to measure the geopotential directly using Doppler shift measurements. This may lead to a foundation for the development of a next generation satellite system for geodesy in the future.
2

Posouzení vybraných metrologických charakteristik měřidel bodové rychlosti vodního proudu využívající elektromagnetického principu měření / Metrological characteristics of current velocity meters using the electromagnetic principle of measurement

Vítů, Martin Unknown Date (has links)
This master’s thesis deals with the assesment of directional sensivity and accuracy of current stream velocity using electromagnetic induction meters in circumstances simulating the real measurement profiles condictions. The theoretical part of the thesis describes the issue of streamflow measurement in open channels and determination of the relevant measurement uncertainties. It also includes description of the hydraulic circuit and the subject current velocity meters. The experimental part of the thesis focuses on the effect of turbulence on the value and accuracy of measured velocity and directional sensivity of electromagnetic induction meters of current velocity. The results are compared with parameters given by manufacturers, research by other authors and with the metrological characteristics of hydrometric propellers, which are commonly used for streamflow measurement in open channels.

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