HYDROACOUSTIC DETERMINATION OF OBJECT SPATIAL CHARACTERISTICS Russian patent published in 2015 - IPC G01S15/58 

FIELD: physics.

SUBSTANCE: invention relates to hydroacoustics. Claimed method comprises radiation of probing signal at time t of echo signal t_echo reception. Distance D to the object is defined from time delay and known sound propagation velocity C. After radiation, measured is the level of volumetric reverberation U₀ to define the detection threshold U_thresh. Measured is the echo signal start time t_start whereat echo signal amplitude A_vol exceeds the threshold A_vol>U_thresh to define the distance D₀ = 0.5 C t_start. Measured is the time of the last amplitude t_last whereat the minimum amplitude of eco signal from the object A_vol>U_thresh to define the time of shadow start time t_shadow whereat the condition U₀≥A_shadow and t_shadow>t_last is satisfied. Defined is the shadow end time t_{shad. end} whereat U_thresh>A_vol≥U₀ to define the distance to the shadow end time D_shad = 0.5 C t_{shad. end}. Now, the depth from hydrophone to the bottom H_bot, while object height is defined by the formula $$h=\frac{(D_{shad}-D_0)H_{bot}}{D_0}.$$

EFFECT: determination of object detection height above bottom by one pulsing.

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