HYDROACOUSTIC NAVIGATION SYSTEM Russian patent published in 2012 - IPC G01S15/08 

FIELD: physics.

SUBSTANCE: hydroacoustic navigation system has a bottom navigation base consisting of M transponders with different response frequencies f_m, the navigation object being fitted with an acoustic transmitter with sampling frequency f₀, an M-channel receiver for receiving response signals with frequencies f_m, M devices for measuring the propagation time of acoustic signals to a transponder operating at the frequency of that channel, and back, M×N units for converting time intervals to distance based on the number N of possible beam paths, the inputs of which are connected to outputs of the corresponding devices for measuring propagation time, a device for calculating coordinates of the navigation object, an additional second bottom navigation base consisting of M transponders with different radiation frequencies F_m (m=1-M), which are mechanically connected to the corresponding M transponders; when determining coordinates of the navigation object, the speed of sound in water is considered, wherein transponders of the first and second navigation bases are formed from transponders in form of spherical surfaces; transponders of the first navigation base are made from acoustically hard materials, and transponders of the second base are made from acoustically soft materials; at points which form the second navigation base, beacons are placed in groups at distances from the corresponding separate beacon shorter than the duration of the probe pulse of the acoustic transmitter; the acoustic transmitter emits a signal towards the transponders with linear frequency modulation; the navigation object is fitted with a sensor for measuring speed of sound in water, which is mounted on the depth level of the acoustic transmitter.

EFFECT: easier determination of coordinates of submerged objects, high measurement accuracy.

10 dwg