Decaying Law Of Short Range Bottom Reverberation

Oceanic reverbefation is one of the fiercest interference to the sonap and itcontains a lot of information of the ocean. So researches about oceanicreverberation is meaningful. Average intensity is one of the physical parameterswhich are used to describe the oceanic reverberation and the researches about ithad been carried out a long time before. but not thoroughly yet. In this thesis,some useful rules fOr average reverberation intensity decaying are given basing onthe work Which have been done by other researchers.First, the formula for average intensity of ocean reverberation is deduced onthe basis of Ray theon' fOr monostatic case, then it is proved by computersimulation and experiment data. lt is obvious that the decaying rule of averagereverberation intensity is affected by scattering coefficient of sea floor, soundspeed profile, inclination of bottom etc. The sea floor scattering function is themost importan factor to the intensity decaying rule. The sound speed profile isanother important factor, the bigger sound speed gradient, the faster reverberationintensity decay And the other factor to the reverberation intensity decaying is seafloor inclination, the greater the slope angle, the slower reverberation intensitydecav.Secondly, the effect of thermocline to the intensity decaying rule fOrmonostatic case is analysed. The thermocline causes omittable effect on theintensity decaying speed. But the site of hydrophone affects the reverberationintensity When hydrophone lies uPper than the thermocline, the reverberationintensity is greater than when there is no thermocline, and vice versa.At last, the average intensity of reverberation for bistatic case had beendeduced. The bistatic average intensity firstly rises wt time to a top point, then itgoes down, and the decaying rule is close to the monostatic reverberation intensityap)J{jgJ:8kq@f9tt&zdecaying rule, but reverbefation intensity will be closely related to the relative siteof the transducers.