The Laser Remote Sensing of Underwater Acoustic Signal

Some underwater targets can give off regular sound wave. When the pressure change due to underwater acoustic signal fluctuation transmitting to the water surface, it may cause slight disturbance at the interface between water and the air, which means that the reflected laser beam carries the information of the underwater acoustic signal since the corresponding laser beam has been modulated. Some necessary information can be obtained through photoelectric detection, demodulation and wave transformation of the reflected or scattered beam of laser. Integrated the transmission characteristics of acoustic signal under seawater with the one of laser beam in free space, one new laser remote sensing technology is suggested which is an effective way to recognize underwater targets and realize on-board active scanning, acquisition, pointing and tracking over a wide range. Experiments validate the feasibility of laser detection of underwater acoustic signal.