CN-120669249-B - Ocean internal wave feature extraction method based on acoustic echo intensity

CN120669249BCN 120669249 BCN120669249 BCN 120669249BCN-120669249-B

Abstract

The invention discloses an ocean internal wave characteristic extraction method based on acoustic echo intensity, which comprises the steps of distributing acoustic emission receivers at 3 different stations in a target sea area, acquiring acoustic echo intensity profile data at the different stations, calibrating the occurrence depth, amplitude and period information of an internal wave according to the maximum value and the occurrence frequency of the acoustic echo intensity profile gradient, and calculating the propagation direction and the propagation speed of the internal wave according to the distance between every two stations and the time delay. By adopting the technical scheme of the invention, the key information such as the wavelength, the period, the amplitude, the propagation speed, the propagation direction and the like of the internal wave can be accurately and rapidly extracted, and the method is suitable for monitoring and early warning of the ocean internal wave.

Inventors

LI JUNYI
QIU HONGRUI
XIE LINGLING
LI MIN

Assignees

广东海洋大学

Dates

Publication Date: 20260508
Application Date: 20250728

Claims (3)

1. The marine internal wave characteristic extraction method based on the acoustic echo intensity is characterized by comprising the following steps of: 3 sound wave transmitting and receiving devices are distributed at fixed points in a target sea area; the 3 sound wave transmitting and receiving devices are used for receiving echo signals reflected by scatterers in the sea water by transmitting sound waves upwards or downwards, so that the profile distribution of the sound wave echo intensities of the sea water at different stations is obtained; According to the acoustic wave echo intensity profile distribution at the stations, calculating the acoustic wave echo intensity gradient distribution at each station by using a gradient checking algorithm, and finding the time range and the depth of the occurrence of the maximum value of the echo intensity; Marking the position of the maximum value of the echo intensity, calculating the occurrence frequency of the signal by utilizing a wavelet transformation method, marking the signal with the frequency of the maximum value of the echo intensity belonging to an internal wave frequency band as ocean internal waves, and obtaining the depth, fluctuation amplitude and period information of the ocean internal waves from the depth of the distribution of the maximum value of the echo intensity gradient of each station acoustic wave, the fluctuation range of the signal at different depths and the frequency of the signal; obtaining the time delay of the ocean internal wave according to the time range of the maximum value of the echo intensity between every two stations; Obtaining the propagation direction and propagation speed of the internal wave according to the station distance of each two stations and the time delay of the marine internal wave; When 3 sound wave transmitting and receiving devices are distributed in the ocean, the stations are distributed in an isosceles triangle, and the distance between the stations is 10 to 100 km; when 3 sound wave transmitting and receiving devices are distributed in the ocean, the probe direction of the sound wave transmitting and receiving devices deviates from the vertical direction by 0 to 30 degrees; and 3 sound wave transmitting and receiving devices, wherein the time interval between the sound wave transmitting and receiving devices for transmitting adjacent sound waves is 30 seconds to 1 minute.
2. The method for extracting ocean internal wave characteristics based on acoustic echo intensities according to claim 1, wherein 3 sound wave transmitting and receiving devices are mounted on a sea surface buoy, and sound waves are emitted downwards.
3. The method for extracting ocean internal wave characteristics based on acoustic echo intensities according to claim 1, wherein 3 acoustic wave transmitting and receiving devices are arranged on the sea floor and transmit upwards.

Description

Ocean internal wave feature extraction method based on acoustic echo intensity Technical Field The invention belongs to the technical field of information technology, and particularly relates to an ocean internal wave characteristic extraction method based on acoustic echo intensity. Background Internal waves are fluctuations within the body of ocean water of the density stabilizing layer junction. Unlike surface waves, the maximum amplitude of the internal wave occurs below the sea surface. The phase velocity is about 1 m/s, the amplitude is several meters to several tens of meters, the wavelength is nearly hundred meters to several tens of kilometers, and the period is several minutes to several tens of hours. It is an important cause of mixing of seawater and formation of fine structures. The equal density surface fluctuation caused by the internal wave changes the size and direction of sound velocity, has great influence on sonar, influences the navigation of underwater ships and has destructive effect on offshore facilities, so that the internal wave observation and the analysis and extraction of the characteristics thereof have strong practical significance. The ocean internal wave changes randomly in space-time, the frequency range is wide, and the ocean internal wave needs to be rapidly and densely sampled in a longer time. The newly developed general marine survey apparatus can meet such observation requirements. The most commonly used observation device is an anchor self-contained ocean current meter capable of measuring the temperature, the salinity, the depth and the like of sea water simultaneously, or can detect ocean internal waves in a sound wave mode and the like, a plurality of anchor devices and a plurality of frames of instruments are arranged into a three-dimensional instrument array, the propagation phase velocity of the ocean internal waves can be calculated, and the propagation direction and the forward direction of the internal waves can be estimated. The sea area through which the ocean internal wave passes can cause strong vertical velocity shear to the sea water in the area, and the strong vertical shear causes abnormal vertical distribution of small particle scatterers in the water body, so that a powerful condition is provided for detecting the ocean internal wave distribution by utilizing the sound wave intensity. The anchor submerged buoy is used for measuring internal waves in a contact mode, but the mode may have influence on ship navigation, and the like, so that a non-contact measurement mode of the internal waves, such as observation of ocean internal waves by adopting an acoustic detection mode, is very important for sea areas with high navigation concentration. Disclosure of Invention The invention aims to provide a marine internal wave characteristic extraction method based on acoustic echo intensity. In order to achieve the above purpose, the present invention adopts the following technical scheme: An ocean internal wave feature extraction method based on acoustic echo intensity comprises the following steps: 3 sound wave transmitting and receiving devices are distributed at fixed points in a target sea area; the 3 sound wave transmitting and receiving devices are used for receiving echo signals reflected by scatterers in the sea water by transmitting sound waves upwards or downwards, so that the profile distribution of the sound wave echo intensities of the sea water at different stations is obtained; According to the acoustic wave echo intensity profile distribution at the stations, calculating the acoustic wave echo intensity gradient distribution at each station by using a gradient checking algorithm, and finding the time range and the depth of the occurrence of the maximum value of the echo intensity; Marking the position of the maximum value of the echo intensity, calculating the occurrence frequency of the signal by utilizing a wavelet transformation method, marking the signal with the frequency of the maximum value of the echo intensity belonging to an internal wave frequency band as ocean internal waves, and obtaining the depth, fluctuation amplitude and period information of the ocean internal waves from the depth of the distribution of the maximum value of the echo intensity gradient of each station acoustic wave, the fluctuation range of the signal at different depths and the frequency of the signal; obtaining the time delay of the ocean internal wave according to the time range of the maximum value of the echo intensity between every two stations; and obtaining the propagation direction and propagation speed of the internal wave according to the station distance of each two stations and the time delay of the marine internal wave. Preferably, when 3 sound wave transmitting and receiving devices are distributed in the ocean, the station positions are distributed in an isosceles triangle shape, and the distance between the station positions is 10 to 100 km.