Characterization of measurement errors in a LBL positioning system

In the ocean, due to the non-ideal channel environment, it is difficult to locate the position of the vessel in the sea quickly and exactly. In order to improve the location accuracy of accident vessel in the ocean, one method is to analyze the main cause of the different kinds of the measurement errors to find their solutions to decrease the errors. The subject that Kalman filtering technology is applied in wireless location system is researched in this paper, which can reduce the measurement error and greatly improve the location accuracy.

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Precision Lattice Parameter Measurements with Guinier Camera and Counter Diffractometer: Comparison and Reconciliation of Results

Advances in X-ray Analysis ◽

10.1154/s0376030800012234 ◽

1982 ◽

Vol 26 ◽

pp. 11-24 ◽

Cited By ~ 1

Author(s):

Allan Brown

Keyword(s):

Measurement Errors ◽

Systematic Errors ◽

Lattice Parameter ◽

Precision Measurements ◽

Compound A ◽

X Ray ◽

Random Measurement ◽

Precise Characterization ◽

The Difference

Different procedures used in precision measurements of lattice parameters are, strictly, only valid if they can be shown to give results that are mutually reproducible. For this purpose reproducibility is defined in terms of the parameters a. and standard deviations a. obtained for X-ray specimens of one or more reference materials. The requirement is that all systematic errors should be minimized to a level below that of the random measurement errors. Where these have a Gaussian distribution the significance of the difference, Δa°, between two , measurements can then be Let;Led by evaluating . Thus, if K < 2 the difference, Δa°, cannot be distinguished from the effects of random measurement errors. This condition should be met for specimens of the same sample if reproducibility is good. For K ≥ 3 the value of Δa° is then taken to reflect real differences in the crystalline Jattice of two X-ray specimens of a given compound. A basis is thus created for the study of solid solubility and for the precise characterization of crystalline compounds.

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Analysis of Global Positioning System (GPS) radio occultation measurement errors based on Satellite de Aplicaciones Cientificas-C (SAC-C) GPS radio occultation data recorded in open-loop and phase-locked-loop mode

Journal of Geophysical Research Atmospheres ◽

10.1029/2006jd007764 ◽

2007 ◽

Vol 112 (D9) ◽

Cited By ~ 18

Author(s):

Martin S. Lohmann

Keyword(s):

Global Positioning System ◽

Measurement Errors ◽

Radio Occultation ◽

Open Loop ◽

Positioning System ◽

Gps Radio Occultation ◽

Global Positioning ◽

Occultation Data ◽

Radio Occultation Measurement ◽

Radio Occultation Data

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KNOWLEDGE-BASED METHODS FOR OPTIMUM APPROXIMATION OF GEOMETRIC DILUTION OF PRECISION

International Journal of Computational Intelligence and Applications ◽

10.1142/s1469026810002835 ◽

2010 ◽

Vol 09 (02) ◽

pp. 153-170 ◽

Cited By ~ 2

Author(s):

M. R. MOSAVI

Keyword(s):

Measurement Errors ◽

Adaptive Filters ◽

Essential Feature ◽

Positioning System ◽

Dilution Of Precision ◽

Knowledge Based ◽

Gps Satellites ◽

Satellite Geometry ◽

Influence Measurement ◽

Geometric Dilution Of Precision

Global Positioning System (GPS) satellites signal processing to obtain all in view satellite measurements and to use them to find a solution and to do integrity monitoring forms a major component of the load on the receiver's processing element. If processing capability is limited there is restriction on the number of measurements which can be obtained and processed. Alternatively, the number of measurements can be restricted and the resulting saving in load on the processor can be used to offer more spare processing time which can be used for other user specific requirements. Thus if m visible satellites can provide measurements only n measurements can be used (n < m). The arrangement and the number of GPS satellites influence measurement accuracy. Dilution of Precision (DOP) is an index evaluating the arrangement of satellites. Geometric DOP (GDOP) is, in effect, the amplification factor of pseudo-range measurement errors into user errors due to the effect of satellite geometry. The GDOP approximation is an essential feature in determining the performance of a positioning system. In this paper, knowledge-based methods such as neural networks and evolutionary adaptive filters are presented for optimum approximation of GDOP. Without matrix inversion required, the knowledge-based approaches are capable of evaluating all subsets of satellites and hence reduce the computational burden. This would enable the use of a high-integrity navigation solution without the delay required for many matrix inversions. Models validity is verified with test data. The results are highly effective techniques for GDOP approximation.

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Marks: A New Interval Tool for Uncertainty, Vagueness and Indiscernibility

Mathematics ◽

10.3390/math9172116 ◽

2021 ◽

Vol 9 (17) ◽

pp. 2116

Author(s):

Miguel A. Sainz ◽

Remei Calm ◽

Lambert Jorba ◽

Ivan Contreras ◽

Josep Vehi

Keyword(s):

Dynamical Systems ◽

Measurement Errors ◽

Practical Application ◽

Modal Interval ◽

The Difference ◽

Systems Simulation ◽

And Control ◽

Physical Quantities ◽

Successive Calculation

The system of marks created by Dr. Ernest Gardenyes and Dr. Lambert Jorba was first published as a doctoral thesis in 2003 and then as a chapter in the book Modal Interval Analysis in 2014. Marks are presented as a tool to deal with uncertainties in physical quantities from measurements or calculations. When working with iterative processes, the slow convergence or the high number of simulation steps means that measurement errors and successive calculation errors can lead to a lack of significance in the results. In the system of marks, the validity of any computation results is explicit in their calculation. Thus, the mark acts as a safeguard, warning of such situations. Despite the obvious contribution that marks can make in the simulation, identification, and control of dynamical systems, some improvements are necessary for their practical application. This paper aims to present these improvements. In particular, a new, more efficient characterization of the difference operator and a new implementation of the marks library is presented. Examples in dynamical systems simulation, fault detection and control are also included to exemplify the practical use of the marks.

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