A Study of Geomagnetic Micropulsations Based on the Analysis of Their Power Spectra PDF Download

Author: Neil Fricker
Publisher:
ISBN:
Category : Geomagnetic micropulsations
Languages : en
Pages : 450

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Author: W. F. Stuart
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Richard V. Wilson
Publisher:
ISBN:
Category : Electronics
Languages : en
Pages :

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Author: Roy L. Komack
Publisher:
ISBN:
Category : Earth currents
Languages : en
Pages : 64

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Book Description
An investigation of ultra low frequency electromagnetic signals known as magnetotelluric micropulsations was made. The electric field strength at the earth's surface was measured by means of electrodes placed in the ground. Analog paper chart records of these signals were made at Trinidad, B.W.I., Puerto Rico, and Austin, Texas. These records were later hand-digitized. The power spectra of the signals at each station were computed for a data sample three quarters of an hour long. Certain power spectral peaks in the frequency range from .01 cps to .25 cps were noted. Several previously undiscovered regularities in the spectra of this sample were found. Power spectral peaks occurred at .05, .125, .175, and .225 cps. Also computed were coherencies between signals at all stations. Coherencies above .8 were found between signals recorded at stations more than 2,000 miles apart. The regular features found in the power spectra were also noted in the coherencies. In addition, some spectral line splitting was not obvious in the power spectra appeared in the coherencies. From the evidence presented it is concluded that certain frequency bands of micropulsations are simultaneous over great distances, and probably originate in the outer atmosphere. (Author).

Author: J. A. Jacobs
Publisher: Springer Science & Business Media
ISBN: 3642868282
Category : Science
Languages : en
Pages : 187

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Book Description
The subject of geomagnetic micropulsations has developed extremely rapidly and it is difficult to know when is an appropriate time to pause and assess the sum total of our knowledge-both observational and theoretical. There has in recent years been a tremendous increase in both the quantity and quality of data and also many theoretical ad vances in our understanding of the phenomenon. Undoubtedly there will be further progress in both areas but it seems worthwhile now to review both our knowledge and our ignorance. This book was essen tially completed by the end of April 1969 and tries to give a summary of the subject up to that time. The Earth is enclosed in the magnetosphere, a hollow carved out of the solar wind by the Earth's magnetic field. Above the ionosphere there is a very tenuous thermal plasma of partially ionized hydrogen in diffusive equilibrium with magnetic and gravitational forces, and ener getic protons and electrons that constitute the trapped Van Allen ra diation belts. Throughout this anisotropic and inhomogeneous plasma, natural and man-made electromagnetic energy propagates in a wide variety of modes and frequency bands. This book is concerned with that class of natural signals called geomagnetic micropulsations-short period (usually of the order of seconds or minutes) fluctuations of the Earth's magnetic field.

Author: C. C. Ku
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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"The theory of correlation functions and power spectral analyses is reviewed. Analog spectral analyses are then made of orthogonal components of geomagnetic micropulsations to investigate (a) the diurnal variation of pcs at a given station, (h) spatial variation of pcs at three pairs of stations differing respectively by 500 in longitude, 5.6° in latitude and 15° in latitude. Analog crosscorrelation technique is employed to study the phase relations among the three orthogonal components, both for pcs (pc-3 and pc-4) and pi-2 at a given station. ..."--

Author: Charles R. Wilson
Publisher:
ISBN:
Category : Geomagnetic micropulsations
Languages : en
Pages :

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Author: Edward Wayne Pogue
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 88

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Data taken from the second generation of the Naval Postgraduate School's ocean floor and land geomagnetic data collection system is analyzed to determine the wave nature of Geomagnetic Pulsations in the .05 to 10 Hz range. The measurements were made in Monterey, California during June to September 1982. Three of these experiments were twenty-four hours in length. During two such experiments land and sea data were transmitted to a central point where the signals were recorded simultaneously. Geomagnetic fluctuations were analyzed to determine various factors characterizing the waves. These factors include the power spectral densities, coherences, Stokes parameters, orientation angle, degree of polarization, and ellipicity. The software developed in this research provides an extensive capability for analysis of geomagnetic noise. Long term data collection can utilize it to establish trends in both the spatial and temporal properties of naturally occurring ELF electromagnetic fields. (Author).

Author: University of London
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 434

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Author: John H. Frey
Publisher:
ISBN:
Category :
Languages : en
Pages : 80

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Book Description
Geomagnetic variations with periods ranging from 0.02 seconds to several days have been investigated to ascertain their nature and origins and their relationship to other magnetospheric phenomena. This investigation included the study of local time variation in geomagnetic micropulsations, the study of the average energy of the micropulsation spectrum in six contiguous octave bands, and the comparison of main geomagnetic field variations with the interplanetary magnetic field. Error analysis of spherical harmonic expansions of solar quiet daily variation, Sq, of the earth's main field has been completed. (Author).