The Perturbation of Alternating Geomagnetic Fields by an Island Near a Coastline

1973 ◽  
Vol 10 (4) ◽  
pp. 510-518 ◽  
Author(s):  
L. R. Lines ◽  
F. W. Jones
Keyword(s):  
Magnetic Field ◽  
Field Component ◽  
Method Of Lines ◽  
Three Dimensional ◽  
Field Vector ◽  
Electric Field Vector ◽  
The Earth ◽  
Electric And Magnetic Field ◽  
Contour Plots ◽  
Geomagnetic Fields

The numerical method of Lines and Jones for investigating the problem of the perturbation of alternating geomagnetic fields by three-dimensional conductivity inhomogeneities embedded in a layered Earth is extended to include models in which vertical discontinuities may extend to the grid boundaries. The case considered is that in which the electric field vector is parallel to the strike of the discontinuities at such boundaries. A model which includes an island near a coastline is studied and contour plots as well as profiles of the electric and magnetic field component amplitudes at the surface of the Earth are given.

AN ANALYTICAL SOLUTION OF THE COSMIC RAYS TRANSPORT EQUATION IN THE PRESENCE OF THE GEOMAGNETIC FIELD

2002 ◽  
Vol 17 (12n13) ◽  
pp. 1645-1653
Author(s):  
MARINA GIBILISCO
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Analytical Solution ◽  
Transport Equation ◽  
Geomagnetic Field ◽  
The Earth ◽  
Factorization Technique ◽  
Diffusion Motion ◽  
Geomagnetic Fields ◽  
The Magnetic Field

In this work, I study the propagation of cosmic rays inside the magnetic field of the Earth, at distances d ≤ 500 Km from its surface; at these distances, the geomagnetic field deeply influences the diffusion motion of the particles. I compare the different effects of the interplanetary and of the geomagnetic fields, by also discussing their role inside the cosmic rays transport equation; finally, I present an analytical method to solve such an equation through a factorization technique.

Frequency and Time Response of Power Plant Grounding System Exposed to Lightning Strike

2016 ◽  
Vol 6 (2) ◽  
pp. 512
Author(s):  
Srete N Nikolovski ◽  
Zoran Baus ◽  
Goran Knežević
Keyword(s):  
Magnetic Field ◽  
Power Plant ◽  
Scalar Potential ◽  
Three Dimensional ◽  
Lightning Strike ◽  
Fast Fourier Transformation ◽  
Theory Approach ◽  
Grounding System ◽  
Lightning Current ◽  
Electric And Magnetic Field

This paper examines the frequency response of power plant grounding system exposed to the lightning current. Large amount of current generated by the stroke flow in the grounding system of power plant and dissipate in the soil.  The electric and magnetic field generated by such high voltages and currents may cause damage of equipment and may be dangerous for the personnel in power plant.  For the every given frequency obtained using Fast Fourier Transformation (FFT) of lightning current impulse, electromagnetic field theory approach is used to solve Maxell’s equation and compute scalar potential, electric and magnetic field. Also, the influence of the point in which lightning current is diffused in the grounding system is presented. Three dimensional plots of spatial distribution of scalar potential, electric and magnetic field are presented. The time domain response of scalar potential, electric and magnetic field on one profile is also presented.

Three-Dimensional Electric Field Vector Measurements in Nitrobenzene Using Kerr Effect

1994 ◽  
Vol 33 (Part 1, No. 4A) ◽  
pp. 2066-2071 ◽  
Author(s):  
Haruo Ihori ◽  
Sadahito Uto ◽  
Kimihiro Takechi ◽  
Kiyomitsu Arii
Keyword(s):  
Electric Field ◽  
Kerr Effect ◽  
Three Dimensional ◽  
Field Vector ◽  
Electric Field Vector

A generalized multibody model for inversion of magnetic anomalies

Geophysics ◽  
1980 ◽  
Vol 45 (2) ◽  
pp. 255-270 ◽  
Author(s):  
B. K. Bhattacharyya
Keyword(s):  
Magnetic Field ◽  
Three Dimensional ◽  
Magnetization Vector ◽  
Critical Dimension ◽  
Magnetic Anomalies ◽  
Field Vector ◽  
Magnetic Survey ◽  
Multibody Model ◽  
Anomalous Field ◽  
Rectangular Block

The height of the observation surface above a magnetized region primarily determines the critical dimension of the smallest inhomogeneity in magnetization that can be resolved from magnetic survey data. When a rectangular block is smaller in size than this critical dimension, it appears homogeneously magnetized in the observed magnetic field. This consideration leads to the selection of a unit rectangular block of suitable dimensions with homogeneous magnetization. The magnetized region creating the anomalous field values in the area of observation can, therefore, be broken up into several blocks having different magnetizations, each block being equal in size and uniformly magnetized. The iterative method described here assumes initially that the anomalous field values are caused by a three‐dimensional (3-D) distribution of magnetized rectangular blocks. The optimum orientation of these blocks with respect to geographic north is then determined. This orientation is particularly insensitive to adjustments in the dimensions of the blocks. The top and bottom surfaces of each of the blocks in one or more layers are adjusted in a least‐squares sense to minimize the difference between observed and calculated field values. A method is also described for constraining the magnetization vector of each block to lie within a specified angle of the normal or reversed direction of the geomagnetic field vector. The procedure for analysis of data can also be extended to the case of anomalies over a draped surface. At the conclusion of the iterations, a 3-D distribution of magnetization is generated to delineate the magnetized region responsible for the observed anomalous magnetic field. Examples including model and aeromagnetic data are provided to demonstrate the usefulness of a generalized multibody model for inversion of magnetic anomalies.

The effect of ionospheric refraction on the polar diagram of a short radio antenna

1968 ◽  
Vol 303 (1473) ◽  
pp. 157-173 ◽  
Keyword(s):  
Magnetic Field ◽  
Incident Wave ◽  
Loop Antenna ◽  
Space Vehicles ◽  
Polar Diagram ◽  
The Earth ◽  
Small Dipole ◽  
Electric And Magnetic Field ◽  
Radio Signals ◽  
Small Antenna

Recently radioastronomers have used receivers in space vehicles in the upper part of the ionosphere to measure radio signals at frequencies which cannot penetrate the F region. When the results are interpreted, the effect of ionospheric refraction is important. This paper shows how to calculate the electric and magnetic field components at a point within the ionosphere when a plane unpolarized wave is incident from outside the Earth at a series of different angles. The anisotropy of the ionosphere, produced by the Earth’s magnetic field, has a profound effect on these fields. The received signal voltage across a small dipole or loop antenna can be found from these fields if the orientation of the aerial is known. Thus a given small antenna and the ionosphere together form a receiving system whose sensitivity varies with the direction of the incident wave. Diagrams showing this variation may be called polar diagrams by analogy with the diagrams often used for directive aerials. Some examples of the shapes of these diagrams are given.

The earth's constants from combined electric and magnetic measurements partly in the vicinity of the emitter

1948 ◽  
Vol 3 (8-11) ◽  
pp. 552-558
Author(s):  
Karel Frederik Niessen
Keyword(s):  
Magnetic Field ◽  
Magnetic Measurements ◽  
Simple System ◽  
Mathematical Form ◽  
The Earth ◽  
Electric And Magnetic Field ◽  
The Magnetic Field

AbstractIn this article a way is indicated for the determination of the soils constants, based upon measurements of both the electric and the magnetic field (remote from but also in the vicinity of the emitter). The method is based especially upon the different behaviour of the electric and magnetic field as a function of the distance in the vicinity of the emitter. Owing to this difference and its mathematical form it will be possible to derive the required constants of the earth by means of one simple system of curves, which may be used again in every other case, as the curves do not depend upon the distances of the points of observation from the emitter. This greatly simplifies the solution of the problem.

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