Author: Vladimir E. Ostashev
Publisher:
ISBN:
Category : Atmosphere
Languages : en
Pages : 15
Book Description
Most previous research on sound propagation in the turbulent atmosphere has focused on nearly horizontal propagation. Sound propagation over vertical and slanted paths is fundamentally different from horizontal propagation in that the variances and length scales of the turbulence depend on the height above the ground. In this paper, propagation over vertical and slanted paths is studied using approaches and methods developed for wave propagation through inhomogeneous, random media. Statistical characteristics of sound signals such as the extinction coefficient of the mean sound field, the strength parameter, the transverse mutual coherence function, the coherence radius, and the correlation functions and variances of the phase and log-amplitude fluctuations are calculated for arbitrary spectra of temperature and wind velocity fluctuations, and then specialized to the von Kármán model for the turbulence spectra. The extinction coefficient and coherence radius are analyzed numerically for various meteorological conditions of the atmospheric boundary layer. The results obtained are compared with those for near-horizontal sound propagation. The theory has applications to localization of elevated sound sources with ground-based microphone arrays, and the detection of ground-based sources with elevated arrays.
Statistical Characterization of Sound Propagation Over Vertical and Slanted Paths in a Turbulent Atmosphere
Author: Vladimir E. Ostashev
Publisher:
ISBN:
Category : Atmosphere
Languages : en
Pages : 15
Book Description
Most previous research on sound propagation in the turbulent atmosphere has focused on nearly horizontal propagation. Sound propagation over vertical and slanted paths is fundamentally different from horizontal propagation in that the variances and length scales of the turbulence depend on the height above the ground. In this paper, propagation over vertical and slanted paths is studied using approaches and methods developed for wave propagation through inhomogeneous, random media. Statistical characteristics of sound signals such as the extinction coefficient of the mean sound field, the strength parameter, the transverse mutual coherence function, the coherence radius, and the correlation functions and variances of the phase and log-amplitude fluctuations are calculated for arbitrary spectra of temperature and wind velocity fluctuations, and then specialized to the von Kármán model for the turbulence spectra. The extinction coefficient and coherence radius are analyzed numerically for various meteorological conditions of the atmospheric boundary layer. The results obtained are compared with those for near-horizontal sound propagation. The theory has applications to localization of elevated sound sources with ground-based microphone arrays, and the detection of ground-based sources with elevated arrays.
Publisher:
ISBN:
Category : Atmosphere
Languages : en
Pages : 15
Book Description
Most previous research on sound propagation in the turbulent atmosphere has focused on nearly horizontal propagation. Sound propagation over vertical and slanted paths is fundamentally different from horizontal propagation in that the variances and length scales of the turbulence depend on the height above the ground. In this paper, propagation over vertical and slanted paths is studied using approaches and methods developed for wave propagation through inhomogeneous, random media. Statistical characteristics of sound signals such as the extinction coefficient of the mean sound field, the strength parameter, the transverse mutual coherence function, the coherence radius, and the correlation functions and variances of the phase and log-amplitude fluctuations are calculated for arbitrary spectra of temperature and wind velocity fluctuations, and then specialized to the von Kármán model for the turbulence spectra. The extinction coefficient and coherence radius are analyzed numerically for various meteorological conditions of the atmospheric boundary layer. The results obtained are compared with those for near-horizontal sound propagation. The theory has applications to localization of elevated sound sources with ground-based microphone arrays, and the detection of ground-based sources with elevated arrays.
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 440
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 440
Book Description
International Aerospace Abstracts
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 974
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 974
Book Description
Journal of the Optical Society of America
Author:
Publisher:
ISBN:
Category : Imaging systems
Languages : en
Pages : 724
Book Description
Publisher:
ISBN:
Category : Imaging systems
Languages : en
Pages : 724
Book Description
Advisory Group for Aerospace Research and Development Index of Publications
Author: North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 446
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 446
Book Description
Electrical & Electronics Abstracts
Author:
Publisher:
ISBN:
Category : Electric industries
Languages : en
Pages : 1248
Book Description
Publisher:
ISBN:
Category : Electric industries
Languages : en
Pages : 1248
Book Description
The Journal of the Acoustical Society of America
Author: Acoustical Society of America
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 1350
Book Description
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 1350
Book Description
Radiowave Propagation in Satellite Communications
Author: Louis J. Ippolito
Publisher: Springer Science & Business Media
ISBN: 9401170274
Category : Technology & Engineering
Languages : en
Pages : 249
Book Description
Radiowave Propagation in Communications was written with two basic objec tives: (l) to present an up-to-date review of the major radiowave propagation phenomena which hinder reliable space communications, and (2) to describe how these propagation phenomena affect the design and performance of satellite communications systems. Earth-orbiting satellites are employed extensively for the relay of information in a vast array of telecommunications, meteorological, government, and sci entific applications. Satellite systems rely on the transmission of radiowaves to and from the satellite and are dependent on the propagation characteristics of the transmission path, primarily the earth's atmosphere. Radiowave propagation thus plays a very important part in the design and ultimate performance of space communications systems. This book presents, for the first time, the meshing in a single publication of the fundamentals of radiowave propagation factors with a discussion of the practical consequences of these factors on satellite communications systems. Two major subfie1ds are involved in this book. Radiowave propagation, which is basically applied electromagnetic theory, provides the theory and an alytical tools for the first several chapters. Later chapters then apply propagation effects to the field of electrical engineering involved with satellite communi cations. The material progresses from the essential aspects of radiowave prop agation to the application of practical methods and techniques in the design and performance of satellite communications systems.
Publisher: Springer Science & Business Media
ISBN: 9401170274
Category : Technology & Engineering
Languages : en
Pages : 249
Book Description
Radiowave Propagation in Communications was written with two basic objec tives: (l) to present an up-to-date review of the major radiowave propagation phenomena which hinder reliable space communications, and (2) to describe how these propagation phenomena affect the design and performance of satellite communications systems. Earth-orbiting satellites are employed extensively for the relay of information in a vast array of telecommunications, meteorological, government, and sci entific applications. Satellite systems rely on the transmission of radiowaves to and from the satellite and are dependent on the propagation characteristics of the transmission path, primarily the earth's atmosphere. Radiowave propagation thus plays a very important part in the design and ultimate performance of space communications systems. This book presents, for the first time, the meshing in a single publication of the fundamentals of radiowave propagation factors with a discussion of the practical consequences of these factors on satellite communications systems. Two major subfie1ds are involved in this book. Radiowave propagation, which is basically applied electromagnetic theory, provides the theory and an alytical tools for the first several chapters. Later chapters then apply propagation effects to the field of electrical engineering involved with satellite communi cations. The material progresses from the essential aspects of radiowave prop agation to the application of practical methods and techniques in the design and performance of satellite communications systems.
Applied mechanics reviews
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 400
Book Description
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 400
Book Description
Applied Science & Technology Index
Author:
Publisher:
ISBN:
Category : Electronic journals
Languages : en
Pages : 2216
Book Description
Publisher:
ISBN:
Category : Electronic journals
Languages : en
Pages : 2216
Book Description