Chinese Academy of Sciences

Changhong Wang

Weiqing Zhu

Min Zhu

Xiaodong Liu

Feng Pan

Xiangjun Zhang

Yuling Wang

The present invention discloses a method and a system for measuring flow layer velocities using correlation velocity measuring sonar. The present invention provides a new theoretical expression for fluid medium sonar array temporal and spatial correlation function, the velocities of each flow layer are derived by fitting experimental data and a theoretical function, or fitting absolute value operated and localized experimental data and a theoretical function. The fluid medium sonar array temporal and spatial correlation function of the present invention is succinctly expressed by Kummer function, and well coincided with the experiments. This function is applicable not only to far field region, i.e. planar wave region, but also Fraunhofer region, i.e. spherical wave region. The present invention has the merits of high measurement accuracy, small calculation load, good robustness and fast convergence.

Method and system for measuring flow layer velocities using correlation velocity measuring sonar

A method and a system for measuring the velocity of a vessel relative to the bottom using a velocity measuring correlation sonar are disclosed. The present invention provides a new theoretical expression for the bottom medium sonar array temporal and spatial correlation function. The velocity of the vessel relative to the bottom is derived by fitting experimental data to a theoretical function. The bottom medium sonar array temporal and spatial correlation function of the present invention is succinctly expressed in zero-rank Bessel function, and well coincided with experiments. The function is applicable not only to far field region, i.e. planar wave region, but also to Fraunhofer region, i.e. spherical wave region. Transmit transducers and receive transducers are multistatic in the velocity measuring correlation sonar of the present invention, so the transmit beam width and the receive beam width can be selected reasonably. The present invention is applicable to measuring the velocity of the vessel relative to the bottom with high measurement accuracy, small calculation load, good robustness and fast convergence.

Method and system for measuring the velocity of a vessel relative to the bottom using velocity measuring correlation sonar

A high resolution bathymetric sidescan sonar system for measuring micro-geomorphy of the sea bottom having an underwater vehicle, an underwater electronic subsystem mounted on the underwater vehicle and containing a transmitter and a receiver, and two sonar arrays mounted symmetrically on two sides of a lower part of the underwater vehicle and being connected to the underwater electronic subsystem through a cable. Each sonar array has a transmitting linear array and three or more parallel receiving linear arrays. The parallel receiving linear arrays are arranged at equal spaces, and the space d between two adjacent parallel receiving linear arrays is &#x3bb;&#x3e;d&#x2267;&#x3bb;/2, in which &#x3bb; is a wavelength of an acoustic wave, and an operation frequency of the parallel receiving linear arrays ranges from 30 kHz to 1200 kHz.

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Beijing, China

Changhong Wang