Patent RU-2650842-C1 (RU)
Inventor: Kasatkin Boris Anatolevich
IPC: G01S15/04
Filed: 2017-05-16
Granted: 2018-04-17
Abstract: FIELD: hydro acoustics. 
     SUBSTANCE: invention relates to the field of hydro acoustics and can be used in the development of search facilities for objects that are at the bottom beneath a layer of soil and invisible to such sonar tools as a side-scan sonar. From the carrier of the sonar equipment, a underwater sound projector emits a pulsed acoustic signal emits to the aqueous medium, acoustic signal reflected from the object in the thickness of the bottom soil of the object is received by the receiving system, the propagation time of the acoustic signal from the radiator to the receiving system is measured, distance from the receiving system to the object is calculated, the carrier of the sonar equipment with the hydroacoustic emitter above the bottom is moved relative to the intended location of the object at a distance from the bottom of Z 1 , connected with the depth Z 2  the proposed location of the object in the earth's thickness, relation Z 1 ρ 1 =Z 2 ρ 2  (ρ 1 , ρ 2  – density of the aquatic medium and soil, respectively) and the space-time location of the object is displayed, while using a bottom acoustic combined receiver as a receiving system, to increase the range of action and the depth of sound wave penetration into the soil, a low-frequency phase-shift signal is used as a pulsed acoustic signal (λ≥Z 2 , λ – wavelength), and the carrier of the sonar equipment with the radiator is moved along a circular trajectory in the center of which the receiving system is located. Use of a low-frequency phase-shifted signal in the radiation mode and correlation algorithms for processing the received signal allows maintaining a high resolution in range, and to increase the noise immunity of the receiving system, the range and high resolution of the angular coordinate a static fan of the directional characteristics is formed in the reception mode, containing 8 horizontal one-way directed spatial channels, shifted relative to each other by 45°, is measured in the n-th spatial channel, oriented to the carrier of the sonar equipment with the radiator, the propagation time of the acoustic signal from the radiator to the receiving system, measured in the spatial channel, oriented to the object located in the thickness of the bottom soil, propagation time of the acoustic signal from the radiator to the object in the thickness of bottom soil and from the object to the receiving system, using for improving the accuracy of the propagation time measurement the correlation algorithms for processing the received phase-shift signal, horizontal distance from the object in the thickness of bottom soil to the receiving system is determined, the coordinates of which are considered to be known, horizontal components of the intensity vector in the local coordinate system associated with the combined receiver are calculated, are calculated in the local coordinate system associated with the combined receiver, bearing on the object in the soil, bearing measured in the local coordinate system associated with the combined receiver is converted into a geographic coordinate system and the location of the object located in the thickness of the bottom soil is determined, with coordinates (r, ϕ geo ), measured relative to the receiving system, which coordinates are assumed to be known. 
     EFFECT: technical result is an increase in the penetration depth of the sound wave into the soil and the range of action while maintaining a high resolution in range and angular position of the object. 
     1 cl, 1 dwg