Re: Literatur und Forschung
Verfasst: 20.12.2010
Infrasound
A summary of 35 years of infrasound research
Ludwik Liszka
Swedish Institute of Space Physics
Aus dem Vorwort:
"... The author’s interest in infrasound emerged from a decade of studies of wave phenomena in the ionosphere. These phenomena appeared frequently on radio-recordings of signals from artificial satellites, which started to populate space at the end of the 1950´s. These oscillations in the electron density, influencing the propagation of radio signals, were evidently a result of the propagation of low-frequency pressure waves through the atmosphere. When infrasound and its unusual propagation properties was rediscovered during the 1960’s in connection with atmospheric nuclear tests, it became obvious that the recording of infrasonic waves at the ground level could contribute to a better understanding of wave phenomena in the atmosphere.
This book is a summary of more than 35 years spent by the author and his co-workers within the field of infrasound. The work was strongly biased towards development of detection techniques with highest possible sensitivity and accuracy of pinpointing direction of origin..
The infrasound studied here, with frequencies between 0.5 and 10 Hz, at the levels occurring in the environment, is completely undetectable by human hearing. We are thus surrounded by a world of non-audible sounds, carrying vast amounts of information, which we cannot apprehend. It has therefore been a very exciting journey through a process of identifying new signal types and their properties, and finally finding their origins. This journey is, apparently,far from over. We continually find new infrasonic signatures, which cannot be immediately
explained. ..."
http://documents.irf.se/get_document.ph ... &docid=884
A summary of 35 years of infrasound research
Ludwik Liszka
Swedish Institute of Space Physics
Aus dem Vorwort:
"... The author’s interest in infrasound emerged from a decade of studies of wave phenomena in the ionosphere. These phenomena appeared frequently on radio-recordings of signals from artificial satellites, which started to populate space at the end of the 1950´s. These oscillations in the electron density, influencing the propagation of radio signals, were evidently a result of the propagation of low-frequency pressure waves through the atmosphere. When infrasound and its unusual propagation properties was rediscovered during the 1960’s in connection with atmospheric nuclear tests, it became obvious that the recording of infrasonic waves at the ground level could contribute to a better understanding of wave phenomena in the atmosphere.
This book is a summary of more than 35 years spent by the author and his co-workers within the field of infrasound. The work was strongly biased towards development of detection techniques with highest possible sensitivity and accuracy of pinpointing direction of origin..
The infrasound studied here, with frequencies between 0.5 and 10 Hz, at the levels occurring in the environment, is completely undetectable by human hearing. We are thus surrounded by a world of non-audible sounds, carrying vast amounts of information, which we cannot apprehend. It has therefore been a very exciting journey through a process of identifying new signal types and their properties, and finally finding their origins. This journey is, apparently,far from over. We continually find new infrasonic signatures, which cannot be immediately
explained. ..."
http://documents.irf.se/get_document.ph ... &docid=884