HYDROACOUSTIC METHOD OF DETERMINING SPATIAL CHARACTERISTICS OF OBJECT AT BOTTOM Russian patent published in 2016 - IPC G01S15/58 

FIELD: measuring equipment.

SUBSTANCE: invention can be used to measure position parameters of an object detected at the bottom with the help of short-range sonar. Method comprises emission of sounding signal at time t, when after emission the level of volume reverberation U₀ is measured, threshold of detecting echo signal U_thr is determined, distance to object D is defined based on the value of time delay and known speed of sound C propagation, based on bottom echo crossing of detection threshold one determines the time of signal propagation to the bottom t_bottom and distance from sonar to the bottom H_bottom=0.5C t_bottom, measure t_beg time of echo signal arrival when the first threshold crossing occurred, determine distance D₁=0.5C t_beg, measure the end of echo signal emission t_last, when the last threshold crossing occurred, determine distance D_last=0.5C t_last, determine time of first shadow t_shadowFirst at U_thr≥A_ehs.shad greater than echo signal amplitude A_ehs.shad, determine the finish time of shadow t _shadowK, at which the amplitude of echo signal A_ehs.F>U_thr, and determine distance to the finish time of shadow D_shadow = 0.5C t_shadowF., determine horizontal distance to the object start at the bottom $$D_{hor.1}^2=D_1^2-H_{bottom}^2,$$ determine horizontal distance to shadow end $$D_{hor.shadow}^2=D_{shadow}^2-H_{bottom}^2,$$ determine height of the object last reflecting point H_ob=δH_bottom/D_shadow, determine the length L of the object side at the bottom facing the sonar, according to formula: $$L=\sqrt{d^2+{\delta }^2-2d\delta \sqrt{(1-{(\frac{H_{bottom}}{D_{shadow}})}^2}},$$ where d = D_hor.shadow-D_hor.1, .δ= D_shadow-D_last, and the angle of object inclination Q^° relative to the bottom is defined as Q^°=arcsin δ H_bottom/D_shadowL.

EFFECT: determination of object length at the bottom and its angle of inclination relative to the bottom by one sending.

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