Acoustic Scattering Study Of Elastic Cylinder

The problem of target scattering played an important role in target detection and identification in the water. Generally speaking, the underwater mines, submarines and ships are made up by elastic object. When the elastic object was incident by the sound wave, it would radiate elastic wave. Which contained information of elastic object' shape and material.There is different form function in different elastic object, so the form function is very significance to target detection and identification. At present, the calculation of the form function must be known the parameter of the elastic object. However, in fact, the signals we received are time domain signals. This paper hope to get the form function from the time domain signals.In theory, we analyze and deduct the form function of the elastic solid cylinder, discuss the relation between the entry angle and frequency. In the Resonance Scattering Theory (RTS), we know the form function can be divided in background part and resonance part. In time domain signal, the background part correspond to the rigid reflected waves, the resonance part correspond to the elastic waves. The two parts of the scattered signal can be divided in time interval.We do the target detection experiments, and receive the target scattered time domain signal. This paper discriminate the rigid reflected waves and elastic waves, which match the theory. By this method, we obtain the form function.We use the Wigner-Ville distribution to analyze the time-frequency relation of the target scattered signal. In the time-frequency image, we observe frequency scattering phenomenon and time-delay phenomenon, which can estimate group velocity. It contributes to the target identification.