Power spectra of geomagnetic fluctuations between 0.02 and 20 Hz
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Authors
Beard, Michael Wayne
Subjects
Geomagnetic Power Spectra
Solar Powered Telemetry
Schumann Resonance Peak Splitting
Concurrent Land-Underwater Data
Solar Powered Telemetry
Schumann Resonance Peak Splitting
Concurrent Land-Underwater Data
Advisors
Moose, Paul
Date of Issue
1981-12
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Fluctuations of the East-West component of the Earth's
geomagnetic field were measured at a remote land site. The
resulting data were transmitted by a solar powered telemetry
system to the Naval Postgraduate School at Monterey, California,
and the power spectra for the frequency range of .02 - 20 Hz
calculated. The measurements, which covered a 4-month
interval (July 20 - October 10, 1981), consistently show a
minimum of activity in the interval 3 - 7 Hz. At frequencies
below the minimum, in the range of .02 - 3 Hz , the typical
monotonic decrease in background activity with frequency was
observed. At 1 Hz an average power spectral density of 1X10" 2
nT2 /Hz was observed during the day and 3.1X10" 3 nT 2 /Hz at night a
In contrast, at frequencies above the minimum, in the range 7-14 Hz, the activity is dominated by the first Schumann
resonance. An evaluation of the East-West component spectra
and concurrent underwater horizontal component measurements
showed a 90% correlation with the underwater spectra. The
underwater field strengths were normally 3-5 dB less than the
strengths measured on land. Splitting of the first Schumann
resonance peak into a doublet structure was observed in 10%
of the land data.
Type
Thesis
Description
Series/Report No
Department
Physics
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.