Gain Calculation Method of Caustics Convergence Region in Deep Sea Complete Sound Channel Based on Parabolic Equation Theory

A parabolic equation and caustics technology, applied in the processing of the detected response signal, the use of sonic/ultrasonic/infrasonic waves to analyze fluids, and the use of sonic/ultrasonic/infrasonic waves for material analysis, etc.

Active Publication Date: 2022-05-10
HARBIN ENG UNIV
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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the gain of the convergence zone near the sea surface is significantly reduced at a long distance, and proposes a method for calculating the gain of the convergence zone of caustics under the complete sound channel in the deep sea based on the parabolic equation theory

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  • Gain Calculation Method of Caustics Convergence Region in Deep Sea Complete Sound Channel Based on Parabolic Equation Theory
  • Gain Calculation Method of Caustics Convergence Region in Deep Sea Complete Sound Channel Based on Parabolic Equation Theory
  • Gain Calculation Method of Caustics Convergence Region in Deep Sea Complete Sound Channel Based on Parabolic Equation Theory

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Embodiment

[0065] The Munk profile, a typical sound velocity profile in the deep sea, is analyzed, and the sound velocity expression of the Munk profile is:

[0066] c(z)=c 0 {1+ε[e -η -(1-η)]} (1)

[0067] Among them, η=2(z-z 0 ) / B,z 0 is the depth of the channel axis, B is the waveguide width, c 0 is the minimum value of sound velocity, and ε is the magnitude of deviation from the minimum value. For a typical Munk model, the parameters are: B=1000m, z 0 = 1000m, c 0 =1500m / s, ε=0.57×10 -2 . The sound velocity profile is as figure 1 shown.

[0068] The depth of the sound source is 300m, and the environment with a sea depth of 6000m is selected for simulation. The signal is filtered with a one-third octave band of the center frequency of 200Hz. Using RAM parabolic equation sound field calculation software, the frequency range is 178-224Hz, with a step of 1Hz Long, the sound field is calculated at each frequency point, and then the frequency average sound intensity is calculate...

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Abstract

The present invention proposes a method for calculating the gain of the caustics convergence area under the complete sound channel in the deep sea based on the parabolic equation theory. In the case of the complete sound channel in the deep sea, the present invention analyzes the typical deep-sea Munk sound velocity profile by using the parabolic equation theory, and obtains the sound pressure According to the expression of sound pressure, the sound intensity is calculated, and the energy-averaged sound intensity value is calculated within the bandwidth of one-third of the octave of the center frequency, and the energy-averaged propagation loss value is calculated accordingly, and then calculated The spherical wave expansion loss value at the caustic line in the lower converging area is obtained, and the energy averaged propagation loss value is compared with the spherical wave spreading loss value, so as to obtain the gain value at the converging area of ​​the lower caustic line, and the result proves that The gain calculation method proposed by the invention has good effect.

Description

technical field [0001] The invention belongs to the technical field of underwater acoustic physics, and in particular relates to a method for calculating the gain of a caustic convergence region under a deep-sea complete sound channel based on the parabolic equation theory. Background technique [0002] The deep-sea convergence zone is of great significance to deep-sea long-range sound propagation, and many scholars have studied it. When the sound source is located near the sea surface, caustics and converging regions with high sound intensity will be formed near the sea surface. The so-called caustics refer to the envelope formed near the intersection point of sound rays, and the converging region refers to the high-intensity caustic region formed near the sea surface. The sound intensity anomaly is the decibel value at which the spherical propagation loss is higher than the convergence zone propagation loss. [0003] In 1961, Hale observed a strong convergence effect fro...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N29/44G01N29/48G01N29/02
CPCG01N29/449G01N29/48G01N29/02
Inventor 朴胜春栗子洋张明辉雷亚辉宋扬王笑寒郭俊媛龚李佳张海刚
Owner HARBIN ENG UNIV
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