Title :
Electro-acoustic scattering in an atmosphere with wind
Author :
Tonning, Andreas
Author_Institution :
Dept. of Phys. Electron., Norwegian Univ. of Sci. & Technol., Trondheim, Norway
fDate :
6/1/2003 12:00:00 AM
Abstract :
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.
Keywords :
acoustic arrays; acoustic wave scattering; atmospheric electromagnetic wave propagation; atmospheric techniques; atmospheric temperature; electromagnetic wave scattering; phase control; phase measurement; temperature measurement; velocity measurement; wind; EM wave scattering; acoustic array; acoustic beam; acoustic waves; atmosphere; electro-acoustic scattering; electromagnetic wave propagation; electromagnetic wave scattering; horizontal wind components measurement; interference; nonplanar waves; phase controlled elementary acoustic sources; phase measurement; resonance; scattering characteristics; spherical waves; temperature measurement; wind velocity measurement; Acoustic beams; Acoustic measurements; Acoustic scattering; Atmosphere; Atmospheric measurements; Electromagnetic scattering; Phase measurement; Phased arrays; Resonance; Temperature;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2003.812268