METHOD OF POSITIONING UNDERWATER OBJECTS Russian patent published in 2012 - IPC G01S3/80 

FIELD: physics.

SUBSTANCE: method involves placing acoustic beacons near the coast at a depth 5-10 times greater than the wavelength of the emitted hydroacoustic signal, said acoustic beacons operating in the low-frequency band and emitting composite, primarily phase-shift keyed or frequency-modulated signals with central frequency lower than 10 kHz. Coordinates of the beacons and electronic copies of the signals emitted by said beacons are entered into an on-board system for calculating coordinates of underwater objects. Calculation of coordinates of underwater objects involves an on-board device picking up a useful signal from the acoustic beacons through cross-correlation processing of the received signal with an electronic copy of the emitted signal in real time, wherein for distances shorter than 20 km and shallow sea conditions, the useful arriving first is selected, and for distances greater than 20 km and deep sea conditions, the useful signal arriving last is selected.

EFFECT: longer range and high accuracy of the positioning method, improved functionality and reliability of the method.

2 cl, 1 dwg