CORRELATION METHOD FOR MEASURING THE PARAMETERS OF THE AQUATIC ENVIRONMENT FINE STRUCTURE Russian patent published in 2023 - IPC G01S15/00 

FIELD: hydroacoustics and oceanography.

SUBSTANCE: invention relates to correlation methods for measuring the speed of movement, allowing to determine the speed of the vessel both relative to the bottom and diffusor relatively passively carried by the currents and located in the layers of the fine structure of the ocean's aquatic environment, and is also accompanied by measuring the depths of the water area along the route with the required accuracy. The invention can be used to acoustically measure the space-time pattern of the current field, which is considered as anisotropic and inhomogeneous. The current velocity is a random function of the geographical coordinates of the measurement site, horizon depth and time. In particular, when crossing the field in a horizontal plane, the time correlation intervals of the current velocity are estimated in units of hours, and the spatial correlation interval is estimated up to about thousands of meters. The operability of the method is based on the fact that information is obtained by ultrasonic sounding of sets of scatterers in 1.2,… , i, .., k layers of an inhomogeneous aquatic environment, which are separated by boundary layers with sharp changes in thermodynamic characteristics (temperature, salinity, sound speed, for example, the vertical velocity gradient at the boundaries between layers can exceed 5-10 cm/s per meter of depth), moreover, sets of scatterers are randomly and statistically nonuniformly distributed in the water volumes of the layers (from 1 to k ). Scatterers (bubbles, suspended particles, plankton, various inhomogeneities, etc.) in the layers have neutral buoyancy, are passively transferred by water masses with different linear current velocities v_ilay relative to the bottom, moreover, the magnitude of their acoustic impedance (рс)_1lay, (рс)_{2 lay}, …., (рс)_ilay randomly fluctuate with respect to the value of acoustic impedance (p_avc_av) of aquatic environment, i.e. in the general case, a set of scatterers can be both acoustically soft and acoustically hard relative to the water environment. From an acoustic point of view, plankton is a collection of scatterers in the aquatic environment, the density and compressibility of which differs from those of the surrounding liquid, and the efficiency of ultrasound scattering depends on how much the density and compressibility of the scatterers differ from the corresponding properties of the environment and on the ratio the dimensions of the scatterers and the ultrasonic wavelength are found. Registration of the acoustic resistance of the surface of a set of scatterers, which characterizes its dynamic response to the impact of an elastic wave, resulting in phase shifts either for sound pressure (“acoustically soft” boundary) or for the oscillatory velocity of particles of the environment (“acoustically hard” boundary) in the reflected wave , can make it possible to use this value as an additional classification feature for studying the anisotropic and inhomogeneous spatiotemporal pattern of the current field.

EFFECT: increasing the reliability of obtaining information about the parameters of flows in the layers of the fine structure of a statistically heterogeneous aquatic environment with randomly distributed volumes of scatterers, obtaining a new volume of primary data about the underwater environment and expanding the operational capabilities of the method.

2 cl, 3 dwg