Frequency domain electromagnetic induction: an efficient method for investigating Fort Ancient village dynamics

2020 ◽  
Author(s):  
Claiborne D. Sea ◽  
Eileen G. Ernenwein
Keyword(s):  
Frequency Domain ◽  
Efficient Method ◽  
Electromagnetic Induction ◽  
Fort Ancient

Motion in frequency domain for harmonic balance simulation of electrical machines

2018 ◽  
Vol 37 (4) ◽  
pp. 1449-1460
Author(s):  
Markus Wick ◽  
Sebastian Grabmaier ◽  
Matthias Juettner ◽  
Wolfgang Rucker
Keyword(s):  
Steady State ◽  
Frequency Domain ◽  
Efficient Method ◽  
Harmonic Balance ◽  
Eddy Currents ◽  
Computational Effort ◽  
Electrical Machines ◽  
Accurate Approximation ◽  
Content Type ◽  
Magnetic Devices

Purpose The high computational effort of steady-state simulations limits the optimization of electrical machines. Stationary solvers calculate a fast but less accurate approximation without eddy-currents and hysteresis losses. The harmonic balance approach is known for efficient and accurate simulations of magnetic devices in the frequency domain. But it lacks an efficient method for the motion of the geometry. Design/methodology/approach The high computational effort of steady-state simulations limits the optimization of electrical machines. Stationary solvers calculate a fast but less accurate approximation without eddy-currents and hysteresis losses. The harmonic balance approach is known for efficient and accurate simulations of magnetic devices in the frequency domain. But it lacks an efficient method for the motion of the geometry. Findings The three-phase symmetry reduces the simulated geometry to the sixth part of one pole. The motion transforms to a frequency offset in the angular Fourier series decomposition. The calculation overhead of the Fourier integrals is negligible. The air impedance approximation increases the accuracy and yields a convergence speed of three iterations per decade. Research limitations/implications Only linear materials and two-dimensional geometries are shown for clearness. Researchers are encouraged to adopt recent harmonic balance findings and to evaluate the performance and accuracy of both formulations for larger applications. Practical implications This method offers fast-frequency domain simulations in the optimization process of rotating machines and so an efficient way to treat time-dependent effects such as eddy-currents or voltage-driven coils. Originality/value This paper proposes a new, efficient and accurate method to simulate a rotating machine in the frequency domain.

Advances in Frequency Domain Electromagnetic Induction Techniques for Improved Discrimination and Identification of Buried Unexploded Ordnance

2000 ◽  
Author(s):  
Dean Keiswetter ◽  
Stephen Norton ◽  
I. J. Won ◽  
Ernesto R. Cespedes ◽  
John C. Morgan
Keyword(s):  
Frequency Domain ◽  
Electromagnetic Induction ◽  
Unexploded Ordnance

Frequency domain electromagnetic induction survey in the intertidal zone: Limitations of low-induction-number and depth of exploration

2014 ◽  
Vol 100 ◽  
pp. 14-22 ◽  
Author(s):  
Samuël Delefortrie ◽  
Timothy Saey ◽  
Ellen Van De Vijver ◽  
Philippe De Smedt ◽  
Tine Missiaen ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Intertidal Zone ◽  
Electromagnetic Induction

Sensitivity of multi-coil frequency domain electromagnetic induction sensors to map soil magnetic susceptibility

2010 ◽  
Vol 61 (4) ◽  
pp. 469-478 ◽  
Author(s):  
D. Simpson ◽  
M. Van Meirvenne ◽  
E. Lück ◽  
J. Rühlmann ◽  
T. Saey ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Frequency Domain ◽  
Electromagnetic Induction ◽  
Soil Magnetic Susceptibility

A comparison of discrimination capabilities of time- and frequency-domain electromagnetic induction systems

2005 ◽  
Author(s):  
Sailaja V. Chilaka ◽  
Daniel L. Faircloth ◽  
Lloyd S. Riggs ◽  
Michael E. Baginski
Keyword(s):  
Frequency Domain ◽  
Electromagnetic Induction

Feature extraction and processing of spatial frequency-domain electromagnetic induction sensor data for improved landmine discrimination

2012 ◽  
Author(s):  
Stacy L. Tantum ◽  
Kenneth A. Colwell ◽  
Kenneth D. Morton ◽  
Waymond R. Scott ◽  
Leslie M. Collins ◽  
...  
Keyword(s):  
Feature Extraction ◽  
Spatial Frequency ◽  
Frequency Domain ◽  
Electromagnetic Induction ◽  
Sensor Data ◽  
Induction Sensor ◽  
Spatial Frequency Domain

scholarly journals Field Comparison of Electrical Resistance, Electromagnetic Induction, and Frequency Domain Reflectometry for Soil Salinity Appraisal

Soil Systems ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 61
Author(s):  
Fernando Visconti ◽  
José Miguel de Paz
Keyword(s):  
Electrical Conductivity ◽  
Frequency Domain ◽  
Soil Salinity ◽  
Electrical Resistance ◽  
Electromagnetic Induction ◽  
Linear Regression Models ◽  
Bulk Electrical Conductivity ◽  
Mass Fractions ◽  
Frequency Domain Reflectometry ◽  
Different Depths

By using different physical foundations and technologies, many probes have been developed for on-site soil salinity appraisal in the last forty years. In order to better understand their respective technical and practical advantages and constraints, comparisons among probes are needed. In this study, three different probes, based on electrical resistance (ER), electromagnetic induction (EMI), and frequency domain reflectometry (FDR), were compared during a field survey carried out in a large salt-threatened agricultural area. Information about the soil bulk electrical conductivity (σb) at different depths was obtained with each of the probes and, additionally, other soil properties were also measured depending on the specifications of each instrument and, moreover, determined in samples. On average, the EMI and FDR techniques could be regarded as equivalent for σb measurement, whereas ER gave higher σb values. Whatever the case, EMI, and also ER, had to be supplemented with information about soil clay, organic matter, and water mass fractions to attain, despite this effort, poor soil salinity estimations by means of multiple linear regression models (R2 < 0.5). On the contrary, FDR needed only probe data to achieve R2 of 0.7, though root mean standard error (RMSE) was still 1.5 dS m−1. The extra measurements and calculations that modern electrical conductivity contact probes integrate, specifically, those based on FDR, remarkably increase their ability for soil salinity appraisal, although there is still room for improvement.

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