Study on the optical system for the record of the pulsed acoustic field and the scattering of the cylindrical-like objects buried in underwater sand

11尬roductlon For the vlsuallzatlon and the studies of the physical properties of acoustic ield;the schlierentechnique was the most useful for the co尬Inuous waves[1,2].ReceNwars,the shadowgraphmode was appeared for the recording of＊theing acoustic pulse[3-p].Although the shadowgr地hmode Is used more frequently In experimental fluid dynamics[6],In the irst part of this paper;the response of＊these opticall扯enslty of＊the recorded acoustic pulse related to the acousticpressure gradlem Is st…