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Regional ionospheric model response of geomagnetic storm during March 2015 using data fusion mechanism: GPS, COSMIC RO and SWARM

Emmela Suneetha, Ratnam Devanaboyina Venkata

Acta Geophysica

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2023

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Vol. 71, no. 1

553--566

EN

The total electron content (TEC) maps are chosen as the elementary structures to provide ionospheric corrections for improving the positional accuracy for Global Navigational Satellite Systems (GNSS) users. Availability of total electron content data from a multi-constellation of satellite systems and various ground-based instruments possess an ability to monitor, nowcast and forecast the behavior of the ionosphere region. Conversely, combining ionospheric TEC data from different temporal and spatial scales is a difficult task to augment either ground or space-based ionospheric model's accuracy. And hence, a method like data fusion is essential to illustrate the ionospheric variability and to improve the accuracy of ionospheric models under equatorial ionization anomaly (EIA) conditions. This paper presented the weighted least square data fusion method with multi-instrument TEC data to analyze the EIA TEC structures in the low-latitude Indian region. Both ground-based (GPS TEC from 26 stations in the Indian region) and space-based (FORMOSAT-3/COSMIC RO and SWARM mini satellite constellation) observations are used for the analysis. The spherical harmonic function (SHF) model of order 2, which gives nine SHF coefficients, is implemented. The analysis illustrates that the SHF coefficients followed by TEC data fusion would be useful to investigate the entry, occupancy and exit TEC structures of EIA during geomagnetic storm conditions.

2

A novel and efficient power system state estimation algorithm based on Weighted Least Square (WLS) approach service

Aghdam Farid Hamzeh, Abdolkarimzadeh Mohammad

Journal of Power Technologies

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2019

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Vol. 99, nr 1

15--24

EN

This paper presents a very fast power system state estimating algorithm to solve the power system state estimation problem. Conventional techniques of state estimation, which are based on the Weighted Least Square (WLS) method, face many issues, including lack of observability, high sensitivity to model parameters and long calculation time in large power systems. The main objective of conventional WLS methods is to minimize a linear objective function, while the aim of the presented method is to improve the results of conventional algorithms and obtain the least minimum possible value of the linear objective function alongside solving the problems mentioned above, by means of an iterative method. The proposed approach is tested on IEEE 14, 30 and 57 bus test systems using MATLAB software. The results reflect the considerable performance of the proposed method.

3

Some reliability issues of the corrugated i-beam girder

Sokołowski D, Kamiński M.

Engineering Transactions

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2015

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Vol. 63, iss. 3

297--315

EN

The main aim of this paper is reliability analysis of the corrugated-web I-girder carried out to verify its susceptibility to the random corrosion of the web and to make a comparison of the results of the first and of the second order reliability analysis. The methodology implemented in the study is based on the stochastic finite element method related to the generalized stochastic perturbation technique, where a discretization of the entire structure is carried out with four-node quadrilateral shell finite elements. This is numerically implemented using the FEM engineering system ROBOT and computer algebra system MAPLE, where all probabilistic procedures are programmed. The perturbation-based results are compared with these coming from the Monte-Carlo simulation and with an analytical solution obtained via symbolic integration carried out in MAPLE also. The indices of reliability are determined for the maximum deflections of the beam as the function of an input coefficient of variation of the web’s thickness whose meaning is the extent of a corrosion process.

4

Modelling of Linear Analogue Transducers in Frequency Domain

Tomczyk K.

Przegląd Elektrotechniczny

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2014

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R. 90, nr 6

202--206

EN

The paper presents the method for modelling of linear analogue transducers based on the simultaneous measurement of the amplitude and the phase characteristics in LabVIEW program. The solutions presented are based on the transfer function reparameterisation, which is the basis for the implementation of the weighted least squares procedure [1-3]. The effectiveness of the presented method is verified using an example of the acceleration sensor PCB 338b35 modelling.

PL

Artykuł przedstawia metodę modelowania liniowych analogowych przetworników w oparciu o równoczesny pomiar charakterystyk amplitudowej i fazowej w programie LabVIEW. Przedstawione rozwiązania oparte są na reparametryzacji funkcji przejścia, stanowiącej podstawę do implementacji ważonej metody najmniejszych kwadratów. Efektywność przedstawionej metody została zweryfikowana na przykładzie modelowania czujnika przyspieszenia PCB 338b35.

5

Wpływ usytuowania punktów pomiarowych na przebieg prostej

Moszczyński L.

Przegląd Elektrotechniczny

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2011

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R. 87, nr 3

271-273

PL

W obliczeniach liniowej regresji dla danych które nie są homoscedastyczne najdogodniej zastosować metodę regresji ważonej. Celem artykułu jest pokazanie jaki wpływ na najlepiej dopasowaną prostą regresji ważonej miałoby dodanie nowego punktu pomiarowego. Dzięki temu możliwe jest lepsze planowanie eksperymentu.

EN

When we want to calculate a linear regression line for data that is not homoscedastic, the simplest way to do this is to use weighted least squares regression. The aim of this article is to show what influence the addition of a new measurement point has on the course of "best line" in weighted regression. In this way, the experiment can be planned better.