Modelisation of the Rain Noise in Undersea Acoustics

Sometimes the rain noise is clearly detected behind a sonar antenna.It is caracterized by a dissymetricalspectral repartition at the energy around!a main lrequency.Actually we carry on researchs on mathematical moce!ization ot the dillerent causes at the undersea amoiant noise to separate and identity them.This is the reason why we are interested Dy anexplanation ot the rain noise.We put the hypothesis that this one is due to the collapsus ol the vacuum under the surtace generated hy the shock ot a raindrop on this surtace.Generally a random number or random phenomena generates a socalled lorentzian noise or which the power spectral densrty is symmetricaIJn tact the dissymetrical is simply due to the upper limit at the diameter or raindrops at which the ret Irequency is driven. u mmooucnon:Caryihg on a study tor modetizing the undersea acoustic noise we are interested by the study or the rain noise.This one is indeed disturbing because it is very wetl heard in an area or convergence .For detecting it and rejecting it it is necessary to know its spectral properties.