scholarly journals Acoustic tomography in the atmospheric surface layer

1999 ◽  
Vol 17 (1) ◽  
pp. 139-148 ◽  
Author(s):  
A. Ziemann ◽  
K. Arnold ◽  
A. Raabe
Keyword(s):  
Surface Layer ◽  
Travel Time ◽  
Atmospheric Surface Layer ◽  
Sound Propagation ◽  
Measuring System ◽  
Acoustic Tomography ◽  
Reconstruction Technique ◽  
Two Dimensional ◽  
Sound Waves ◽  
Atmospheric Conditions

Abstract. Acoustic tomography is presented as a technique for remote monitoring of meteorological quantities. This method and a special algorithm of analysis can directly produce area-averaged values of meteorological parameters. As a result consistent data will be obtained for validation of numerical atmospheric micro-scale models. Such a measuring system can complement conventional point measurements over different surfaces. The procedure of acoustic tomography uses the horizontal propagation of sound waves in the atmospheric surface layer. Therefore, to provide a general overview of sound propagation under various atmospheric conditions a two-dimensional ray-tracing model according to a modified version of Snell's law is used. The state of the crossed atmosphere can be estimated from measurements of acoustic travel time between sources and receivers at different points. Derivation of area-averaged values of the sound speed and furthermore of air temperature results from the inversion of travel time values for all acoustic paths. Thereby, the applied straight ray two-dimensional tomographic model using SIRT (simultaneous iterative reconstruction technique) is characterised as a method with small computational requirements, satisfactory convergence and stability properties as well as simple handling, especially, during online evaluation.Key words. Meteorology and atmospheric dynamics (turbulence; instruments and techniques).

Sound propagation in the atmospheric surface layer: Comparison of experiment with FFP predictions

1993 ◽  
Vol 40 (4) ◽  
pp. 325-346 ◽  
Author(s):  
A. L'Espérance ◽  
J. Nicolas ◽  
D.K. Wilson ◽  
D.W. Thomson ◽  
Y. Gabillet ◽  
...  
Keyword(s):  
Surface Layer ◽  
Atmospheric Surface Layer ◽  
Sound Propagation

High-Resolution Fibre-Optic Temperature Sensing: A New Tool to Study the Two-Dimensional Structure of Atmospheric Surface-Layer Flow

2011 ◽  
Vol 142 (2) ◽  
pp. 177-192 ◽  
Author(s):  
Christoph K. Thomas ◽  
Adam M. Kennedy ◽  
John S. Selker ◽  
Ayla Moretti ◽  
Martin H. Schroth ◽  
...  
Keyword(s):  
Surface Layer ◽  
High Resolution ◽  
Atmospheric Surface Layer ◽  
Temperature Sensing ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Fibre Optic ◽  
Layer Flow

Emission spread from mass and energy exchange in the atmospheric surface layer: Two-dimensional simulation

2018 ◽  
Vol 40 (23) ◽  
pp. 2832-2841 ◽  
Author(s):  
Nurgali Zaurbekov ◽  
Allayarbek Aidosov ◽  
Nurbike Zaurbekova ◽  
Galym Aidosov ◽  
Gulzat Zaurbekova ◽  
...  
Keyword(s):  
Surface Layer ◽  
Energy Exchange ◽  
Atmospheric Surface Layer ◽  
Two Dimensional ◽  
Dimensional Simulation

Acoustic travel-time tomography of the atmospheric surface layer at the Boulder Atmospheric Observatory

2016 ◽  
Vol 139 (4) ◽  
pp. 2097-2098
Author(s):  
Vladimir E. Ostashev ◽  
Sergey N. Vecherin ◽  
D. K. Wilson ◽  
Alfred J. Bedard
Keyword(s):  
Surface Layer ◽  
Travel Time ◽  
Atmospheric Surface Layer ◽  
Travel Time Tomography ◽  
Acoustic Travel Time

scholarly journals Acoustic Tomography for Scalar and Vector Fields: Theory and Application to Temperature and Wind Estimation

2009 ◽  
Vol 26 (8) ◽  
pp. 1475-1492 ◽  
Author(s):  
Ivana Jovanović ◽  
Luciano Sbaiz ◽  
Martin Vetterli
Keyword(s):  
Inverse Problem ◽  
Vector Fields ◽  
Sound Propagation ◽  
Time Of Flight ◽  
Reconstruction Algorithm ◽  
Acoustic Tomography ◽  
Bounded Domains ◽  
Sound Waves ◽  
Wind Fields ◽  
Wind Estimation

Abstract Acoustic tomography is a type of inverse problem. The idea of estimating physical quantities that influence sound propagation by measuring the parameters of propagation has proven to be successful in many practical domains, including temperature and wind estimation in the atmosphere. However, in most of the previous work in this area, the algorithms used have not been proven mathematically to provide the correct solution to the inverse problem. This paper considers the problem of reconstructing 2D temperature and wind fields by using acoustic tomography setups. Primarily, it shows that the classical time-of-flight measurements are not sufficient to reconstruct wind fields. As a solution, an additional set of measurements related solely to the parameters of sound propagation—more precisely, to the angles of departure/arrival of sound waves—is suggested. To take the full benefit of this additional information, the bent-ray model of sound propagation is introduced. In this work, it is also shown that, when a temperature and a source-free 2D wind field are observed on bounded domains, the complete reconstruction is possible using only measurements of the time of flight. Conversely, the angles of departures/arrivals are sufficient to reconstruct a temperature and a curl-free 2D wind fields on bounded domains. Further, an iterative reconstruction algorithm is proposed and possible variations to the main scheme are discussed. Finally, the performed numerical simulations confirm the theoretical results, demonstrate fast convergence, and show the advantages of the adopted bent-ray model for sound propagation over the straight-ray model.

Acoustic Travel-Time Tomography of the Atmospheric Surface Layer

2009 ◽  
Author(s):  
Vladimir E. Ostashev ◽  
Alfred J. Bedard ◽  
Sergey N. Vecherin ◽  
D. Keith Wilson
Keyword(s):  
Surface Layer ◽  
Travel Time ◽  
Input Data ◽  
Atmospheric Surface Layer ◽  
Velocity Fields ◽  
Complex Topography ◽  
Atmospheric Models ◽  
Propagation Models ◽  
Travel Time Tomography ◽  
Acoustic Travel Time

Acoustic travel-time tomography of the atmospheric surface layer (ASL) is based on measurements of travel time of sound impulse propagation between different pairs of sources (speakers) and receivers (microphones), which constitute the tomography array. Then, the temperature and wind velocity fields inside the tomography array are reconstructed with inverse algorithms. Improved knowledge about these fields is important in many applications: validation and input data for atmospheric models, studies of turbulence over complex topography and heterogeneous surfaces, input data for wave propagation models, etc.

Sign in / Sign up

Export Citation Format

Share Document