Characterisation of wind field with high resolution in time and space by the use of electromagnetic and acoustic waves

Gjessing, Dag T.; Hansen, R.C.; Saebboe, J.

doi:10.1049/ip-rsn:20010095

Cited by 3 publications

(3 citation statements)

References 12 publications

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“…Acoustic pressure variations have a direct impact on the dielectric inhomogeneities in the surrounding medium. This phenomenon is used to observe wind speed and direction using a method proposed in [12,13].…”

Section: Numerical Approachmentioning

confidence: 99%

Electro-Acoustic Scattering From a Pulsating Sphere

Negi,

Balakrishnan

2023

IEEE J. Multiscale Multiphys. Comput. Tech.

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In this paper, we show the RCS enhancement due to the acoustic disturbances around a pulsating sphere. The acoustic variation is modelled with the dielectric inhomogeneities around the sphere caused by the pressure fluctuations due to the acoustic source. RCS is computed for the modelled dielectric pulsating sphere, a cube and a cone on a cylinder across a frequency band using Finite Difference Time Domain (FDTD) method. The RCS of the pulsating sphere and other objects considered are dominated by the background scattering from the pulsating object. In this work, we show that the dielectric variation due to the acoustic source can be detected even if there is no scattering from the object . The scattering from the dielectric variation leads to the detection of Bragg scattering along with a significant increase in RCS.

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Section: Numerical Approachmentioning

confidence: 99%

Electro-Acoustic Scattering From a Pulsating Sphere

Negi,

Balakrishnan

2023

IEEE J. Multiscale Multiphys. Comput. Tech.

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“…Denoting the electric susceptibility of air by , we take the latter to be proportional to the number density of particles. Hence (1) so that (2) Using the equation of state for gases, assuming adiabatic changes, and replacing the differentials by finite changes, we find (see [1 p. 404 which relates the modulation of electric permittivity to the relative amplitude of the pressure variation. The intensity of a sound wave at height is given by (4) where is the mass density of air.…”

Section: A Modulation Caused By the Acoustic Beammentioning

confidence: 99%

“…The purpose of this work is to study how a wind field influences the scattering, and to discuss the possibility of measuring strength and direction of the wind by observing the scattering. A method for characterization of wind field by scattering of electromagnetic waves from acoustic waves has been published by Gjessing et al [2]. The present paper presents a more detailed analysis of the problem, and introduces an alternative method for continuous monitoring of wind direction and velocity.…”

Section: Introductionmentioning

confidence: 96%

Electro-acoustic scattering in an atmosphere with wind

Tonning

2003

IEEE Trans. Antennas Propagat.

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An electromagnetic wave propagating in the atmosphere is scattered by a beam of acoustic waves. The paper studies how a wind interferes with the scattering process. The purpose is to use the results for measuring the wind velocity and the temperature of the atmosphere at varying heights. A scattering calculation is carried out by means of standard methods used in problems of wave scattering. The scattering characteristics show a pronounced resonance, due to interference between spherical, i.e, nonplanar, waves. The resonance, and particularly the width of the resonance curve, represents a possibility of measuring the temperature of the atmosphere in the scattering region. The paper points out the advantage of having the acoustic beam generated by an array of phase controlled elementary acoustic sources. This opens the possibility of counteracting the effect of the wind on the acoustic beam so that the beam is keeping its direction undisturbed by the wind. By this method the problem of measuring the horizontal wind components is converted to a measurement of phase.

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Characterisation of objects and general ocean phenomena by use of target adaptive multi-frequency multistatic matched illumination acoustics

Gjessing

Saebboe

2002

IEE Proc., Radar Sonar Navig.

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Characterisation of wind field with high resolution in time and space by the use of electromagnetic and acoustic waves

Cited by 3 publications

References 12 publications

Electro-Acoustic Scattering From a Pulsating Sphere

Electro-Acoustic Scattering From a Pulsating Sphere

Electro-acoustic scattering in an atmosphere with wind

Characterisation of objects and general ocean phenomena by use of target adaptive multi-frequency multistatic matched illumination acoustics

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