TECHNIQUE FOR DETECTION OF UNDERWATER TARGET IN GUARDED WATER AREA Russian patent published in 2000 - IPC

FIELD: underwater acoustics, detection and tracking of underwater target in defended water area. SUBSTANCE: surface of water area is irradiated in correspondence with invention with use of modulated laser radiation on wave length 9- 11 μm. Radiation of this wave length is completely absorbed by surface layers of water. Zone of heating turns to be source of acoustic waves. Waves reflected from target are received by sonic detectors. Received signals are processed and then command to irradiate location of presumed position of target with additional modulated laser radiation with wave length 0.6-1.1 μm is given. Radiation of this wave length is capable of reaching target and of heating its surface which becomes additional source of acoustic waves. These acoustic waves are also received by sonic detectors. Processing of information from sonic detectors makes it possible to determine coordinates of target, its speed and direction of movement and to track target by way of corresponding movement or by scanning of laser radiation. EFFECT: increased precision in determination of coordinates of target and in its tracking. 6 cl, 1 dwg