Ocean sound field calculation method, system, device and storage medium

Abstract

The present invention belongs to the technical field of underwater acoustic field detection, and specifically relates to a method, system, device and storage medium for calculating ocean acoustic field, the method comprising: establishing an isoacoustic surface of seawater based on the earth curvature effect, establishing an eikonal equation based on the isoacoustic surface of seawater and environmental information, obtaining the ray sound pressure of the ray beam based on the eikonal equation, Jacobian field, Jacobian equation and correction step length, calculating the sound pressure contribution of the ray sound pressure at the real depth and distance grid, obtaining the grid sound pressure value of all grid points according to the sound pressure contribution, inputting the grid sound pressure value into a preset formula, and obtaining the propagation loss of different receiving points. The present application has the effect of improving the prediction accuracy of ocean acoustic field.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater acoustic field detection, and in particular relates to an ocean acoustic field calculation method, system, equipment and storage medium. Background Art

[0002] Marine acoustics is the foundation for human activities such as ocean exploration, ocean survey, marine economy, and science and technology. It plays an important supporting role in my country's construction of a strong maritime nation and consolidation of marine security. Sound waves are the only information carrier that can be transmitted over long distances in seawater. The sound propagation model is the scientific cornerstone of underwater detection and communication. As an approximate sphere, the curvature of the earth will cause the underwater acoustic waveguide to bend, resulting in errors in the ocean sound field.

[0003] In the related technologies, the sound transmission model mainly adopts the ray method, Gaussian beam method, beam integral method, simple normal wave method and parabola method.

[0004] With respect to the above-mentioned related technologies, the earth is approximately a sphere, and the curvature of the earth will cause the hydroacoustic waveguide to bend. Therefore, for the horizontal layered sound propagation scenario commonly seen in hydroacoustics, the actual sound velocity isosurfaces of ocean sound propagation are concentric spheres, rather than parallel planes. The existing technology uses a conformal mapping method to solve the earth curvature problem in the sound field solution. However, from Gauss's wonderful theorem, it can be seen that there is no equidistant mapping between a sphere and a plane. The conformal mapping method will definitely produce systematic errors, resulting in inaccurate ocean sound field predictions. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method, system, device and storage medium for calculating the ocean sound field. Propagation loss is one of the important parameters for calculating the ocean sound field. By calculating the propagation loss, the absorption, scattering and attenuation characteristics of the ocean medium can be more accurately considered, so that the ocean sound field prediction results are more in line with the actual situation.

[0006] A method for calculating an ocean acoustic field, comprising:

[0007] Based on the effect of earth curvature, establish the constant sound velocity surface of seawater;

[0008] Establishing an Eikonal equation based on the seawater isosonic surface and environmental information;

[0009] Based on the eikonal equation, Jacobian field, Jacobian equation and correction step size, the ray sound pressure of the ray beam is obtained;

[0010] Calculate the sound pressure contribution of the ray sound pressure at the real depth and distance grid;

[0011] According to the sound pressure contribution, the grid sound pressure values ​​of all grid points are obtained;

[0012] The grid sound pressure value is input into a preset formula to obtain the propagation loss at different receiving points.

[0013] Specifically, ocean acoustic field calculation refers to the process of studying and predicting the propagation and propagation characteristics of sound waves in the ocean through mathematical models and calculation methods. It involves analyzing various parameters such as the propagation path, sound speed, attenuation, and scattering of sound waves in the ocean. In order to achieve the prediction of the ocean acoustic field, it is necessary to use mathematical models and calculation methods to predict the propagation characteristics of sound waves and the distribution of sound fields in the ocean in the future based on known ocean environmental conditions and sound source information. The propagation loss is one of the important factors in the accuracy of the sound field prediction. By calculating the propagation loss, the absorption, scattering, and attenuation characteristics of the ocean medium can be considered more accurately, making the prediction results more in line with the actual situation.

[0014] Optionally, establishing the eikonal equation based on the seawater isosonic surface and environmental information includes:

[0015] Obtaining the propagation distance and propagation depth based on the claimed environmental information;

[0016] Based on the propagation distance and the propagation depth, a sound velocity profile is obtained;

[0017] According to the sound velocity profile, a Riemann metric of propagation time under the effect of earth curvature is established;

[0018] Based on the Riemann metric and the geodesic equation, the eikonal equation is obtained.

[0019] Optionally, obtaining the ray sound pressure of the ray beam based on the eikonal equation, the Jacobian field, the Jacobian equation and the corrected step size includes:

[0020] Based on the Eikonal equation and the Jacobian field, a cross-sectional curvature of the sound line is obtained;

[0021] According to the cross-sectional curvature of the sound line, the Jacobi equation is obtained;

[0022] According to the Jacobi equation and the modified step size, the ray sound pressure of the ray beam is obtained.

[0023] Optionally, obtaining the ray sound pressure of the ray beam according to the Jacobi equation and the modified step size includes:

[0024] Get the initial value conditions and initial step size;

[0025] Get reflection conditions;

[0026] Adjust the initial step length based on the reflection condition to obtain the modified step length;

[0027] Solving the eikonal equation and the Jacobi equation according to the initial conditions to obtain the solution;

[0028] The ray sound pressure of the ray beam is obtained based on the solution of the equation and the correction step size.

[0029] Optionally, the calculating the sound pressure contribution of the ray sound pressure at the real depth and distance grid includes:

[0030] Locate the endpoint distance between adjacent ray endpoints;

[0031] Calculating non-ray endpoint values ​​based on the endpoint distance and linear interpolation method;

[0032] Obtaining a receiving distance based on the non-ray endpoint value;

[0033] Determining whether the receiving distance is greater than the beam radius;

[0034] If the receiving distance is greater than the beam radius, the acoustic pressure contribution of a single ray beam at the real depth and distance grid is calculated.

[0035] Optionally, obtaining the grid sound pressure values ​​of all grid points according to the sound pressure contribution includes:

[0036] According to the sound pressure contribution of a single ray beam at the real depth and distance grid, obtaining the sound pressure contribution value of each ray beam to the same grid point;

[0037] Accumulating the sound pressure contribution values ​​of all ray beams to the same grid point to obtain the grid point sound pressure value;

[0038] All grid points are traversed to obtain the grid sound pressure values ​​of all grid points.

[0039] Optionally, inputting the grid sound pressure value into a preset formula to obtain the propagation loss of different receiving points includes:

[0040] The preset formula is:

[0041] ;

[0042] Among them, (r, z) is the receiving point, P is the grid sound pressure value, P0 is the sound intensity at a distance of 1m from the sound source, and TL (r, z) is the propagation loss of the receiving point.

[0043] An ocean acoustic field calculation system, comprising:

[0044] The first building module is used to establish the seawater constant sound velocity surface based on the earth curvature effect;

[0045] A second building block is used to establish an eikonal equation based on the seawater isosonic surface and environmental information;

[0046] A first calculation module, used for obtaining the ray sound pressure of the ray beam based on the eikonal equation, the Jacobian field, the Jacobian equation and the correction step size;

[0047] A second calculation module is used to calculate the sound pressure contribution of the ray sound pressure at the real depth and distance grid;

[0048] A traversal module is used to obtain the grid sound pressure values ​​of all grid points according to the sound pressure contribution;

[0049] The third calculation module is used to input the grid sound pressure value into a preset formula to obtain the propagation loss of different receiving points.

[0050] A terminal device comprises a memory and a processor. The memory stores a computer program that can be run on the processor. When the processor loads and executes the computer program, a method for calculating an ocean sound field is adopted.

[0051] A computer-readable storage medium stores a computer program, and when the computer program is loaded and executed by a processor, the above-mentioned ocean sound field calculation method is adopted.

[0052] The beneficial effects of the present invention are:

[0053] By equating the earth's curvature effect to the seawater isosonic surface, the sound pressure field of the curved sound channel under the earth's curvature effect can be effectively calculated. The considered curved sound channel is more in line with the actual ocean environment, and the sound pressure field of the spherical layered medium can be directly calculated, avoiding the systematic error caused by the curvature correction method. Through equivalent sound velocity surface modeling, the propagation loss of sound waves in the curved sound channel can be more accurately considered. The propagation loss is one of the important parameters in the calculation of the ocean sound field. After accurately calculating the propagation loss, the absorption, scattering and attenuation characteristics of the ocean medium can be more accurately considered, making the forecast results more in line with the actual situation and improving the forecast accuracy of the ocean sound field. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of a flow chart of a method for calculating an ocean acoustic field according to the present invention;

[0055] Figure 2 This is a comparison diagram of the propagation loss between the present invention and the conformal mapping method that does not consider the earth curvature. DETAILED DESCRIPTION

[0056] A method for calculating the ocean acoustic field, such as Figure 1 As shown, the present invention includes:

[0057] S100. Based on the effect of the earth's curvature, establish the constant sound velocity surface of seawater.

[0058] Specifically, the curvature of the sphere is complex and variable, and the distribution of sound speed in seawater is also affected by many factors. Equating the curvature of the earth to a spherical surface of constant sound speed in seawater helps to simplify the sound wave propagation model, making analysis and calculation easier.

[0059] S110, establishing an Eidinokinetic equation based on the seawater isosonic surface and environmental information.

[0060] Specifically, the environmental information includes the coordinates of the sound source and the shape of the seabed, etc. The coordinates of the sound source are usually expressed in terms of propagation distance and propagation depth.

[0061] S120. Based on the eikonal equation, the Jacobian field, the Jacobian equation and the modified step size, the ray sound pressure of the ray beam is obtained.

[0062] Specifically, the Eikonal equation describes the law of change of the propagation path of sound waves underwater or in the ocean, that is, the propagation characteristics of sound waves in different media. The Jacobian field and Jacobian equation are applied to coordinate transformation or medium parameter transformation to calculate the propagation path of sound waves, beam transformation and other information. The correction step size is when calculating, the sound line position needs to be iterated, but the sound line in the actual ocean should be reflected on the sea surface and the seabed, so the step size needs to be corrected to ensure that the sound line does not cross the boundary.

[0063] S130. Calculate the sound pressure contribution of the ray sound pressure at the real depth and distance grid.

[0064] Specifically, a true depth-distance grid refers to a data representation method used in the field of acoustic exploration or imaging. The true depth-distance grid is usually displayed in two or three dimensions, which contains data information at different depths and distances. Depth usually refers to the depth of underground objects or structures, while distance refers to the horizontal distance from the detector or source point to the underground structure. By displaying data on such a grid, the underground structure and properties at different locations can be intuitively displayed.

[0065] Each ray beam will produce sound pressure contribution at each grid point in the multi-grid within a certain range.

[0066] S140. Obtain grid sound pressure values ​​of all grid points according to sound pressure contributions.

[0067] Specifically, the same grid point will be affected by multiple ray sets, so all sound pressure contributions received by the same grid point are superimposed to obtain the grid sound pressure value of the grid point. All grid points are calculated in this way to obtain the grid sound pressure values ​​of all grid points.

[0068] S150, inputting the grid sound pressure value into a preset formula to obtain the propagation loss of different receiving points.

[0069] Specifically, propagation loss refers to the propagation loss of sound waves from the sound source to the receiving point in the ocean.

[0070] In one implementation of this embodiment, step S110, i.e. establishing an eikonal equation based on the seawater isosonic surface and environmental information, includes:

[0071] S200: Acquire a propagation distance and a propagation depth based on the environmental information.

[0072] S210. Obtain a sound velocity profile based on the propagation distance and the propagation depth.

[0073] Specifically, It is a spherical coordinate system with the center of the earth as its origin. is the radius of curvature of the earth. Under radially symmetric conditions, the spherical layered medium can be simplified to a two-dimensional case, where the propagation distance ,depth . is the sound velocity profile in a spherical layered medium. The environmental information includes the propagation distance and propagation depth of the sound source, where is the straight-line distance from the center of the ball to the target point, is the angle between the radial direction (usually taken as the positive z-axis direction) and the target point and the positive z-axis. is the azimuth.

[0074] S220. Based on the sound speed profile, establish the Riemann metric of the propagation time under the effect of the earth's curvature.

[0075] Specifically, the line element of the Euclidean metric in the spherical coordinate system is , the corresponding Riemann metric is Due to the propagation time satisfy , so the line element The metric is .

[0076] S230. Based on the Riemann metric and the geodesic equation, the eikonal equation is obtained.

[0077] Specifically, according to the principle of least action, the metric at the propagation time t Under this condition, the sound rays propagate along the geodesic line. The geodesic equation under the natural parameter t is:

[0078] .

[0079] and Respectively represent the geodesic line and Direction line element, is the Christoffel connection coefficient, calculated as:

[0080] .

[0081] Riemann metric Substituting the equation into the spherical layered medium, we can get the following equation:

[0082]

[0083] Depth distance coordinate The following functional equation can be expressed as:

[0084]

[0085] Phase along the ray satisfy:

[0086] , c is the speed of sound.

[0087] In one implementation of this embodiment, step S120, based on the eikonal equation, the Jacobian field, the Jacobian equation and the modified step size, obtains the ray sound pressure of the ray beam, including:

[0088] S300, based on the Eikonal equation and the Jacobian field, the geometric expansion of the sound line is obtained.

[0089] Specifically, the Jacobian field of the geodesic Describes the inherent geometric expansion of the sound line. Jacobi field Satisfies the Jacobi equation:

[0090] .

[0091] in Represents the cross-sectional curvature, reflecting the geometric topological structure of the manifold.

[0092] S310. According to the geometric expansion of the sound rays, the Jacobi equation is obtained.

[0093] Specifically, the Jacobi equation is:

[0094]

[0095] set up For embedded geometry expansion, is the arc length parameter, is the normal distance from the central sound line. The above equation is equivalent to the paraxial ray equation (Jacobi equation).

[0096] .

[0097] in,

[0098] .

[0099] S320. Obtain the ray sound pressure of the ray beam according to the Jacobi equation and the modified step size.

[0100] Specifically, in order to prevent the sound ray from crossing the boundary, the step size needs to be corrected to prevent the sound ray from crossing the boundary during the calculation process, resulting in inaccurate calculation results.

[0101] In one implementation of this embodiment, step S320, i.e., obtaining the ray sound pressure of the ray beam according to the Jacobi equation and the modified step size, includes:

[0102] S400, obtaining initial value conditions and initial step length.

[0103] S410: Obtain reflection conditions.

[0104] S420: Adjust the initial step length based on the reflection condition to obtain a corrected step length.

[0105] S430, solving the Eikonal equation and the Jacobi equation according to the initial conditions to obtain the solutions of the equations.

[0106] S440: Based on the solution of the equation and the correction step size, the ray sound pressure of the ray beam is obtained.

[0107] Specifically, the initial value conditions are:

[0108] , where q(0) and p(0) are complex numbers, r is the propagation distance, z is the propagation depth, r(0) and z(0) are the source coordinates, s is the arc length parameter, q is the external geometric expansion, τ is the phase, and p is the conjugate momentum of q, where .

[0109] The eikonal equation and the paraxial ray equation are solved by the second-order Runge-Kutta method with a modified step size. Assuming the initial step size is h, To iterate the front sound line position, is the sound line position after iteration, In the actual ocean, the sound line should be reflected on the sea surface and the seabed, so the step length h needs to be corrected to ensure that the sound line does not cross the boundary.

[0110] Since the sea surface and seabed information are in rectangular coordinates, it is more convenient to use rectangular coordinates here. is the depth distance coordinate The corresponding rectangular coordinates are, is the sound line position before iteration, is the sound line position after iteration, is the left endpoint of the segment boundary, is the tangent vector of the incident sound ray, is the unit external normal vector of the boundary, and the above are all rectangular coordinates. The unit tangent vector and normal vector of the sea surface spherical boundary are:

[0111] .

[0112] .

[0113] make , .

[0114] , .

[0115] in, The vector from the boundary point to the endpoint of the ray after iteration, is the normal vector outside the boundary, if , indicating that the angle is less than 90 degrees. The iterated ray passes through the boundary. The step size needs to be corrected so that it hits the boundary exactly. The step size in the rectangular coordinate system is corrected to , the sound line position after iteration is , the true depth is , so the true depth-distance coordinate The next step length correction is:

[0116] .

[0117] The reflection condition is: if and , indicating that the sound is reflected, is modified to the following reflection conditions:

[0118] The incident sound direction vector is decomposed into ,in The direction vector of the reflected sound line is , depth distance coordinate The following is expressed as

[0119] .

[0120] The propagation time of reflected sound rays remains unchanged .

[0121] When a ray passes through or is reflected at a weakly continuous (first-order derivative discontinuity) interface, the beam parameters A jump will occur.

[0122]

[0123] .

[0124] in is the boundary curvature, and for piecewise linear boundaries , the curvature of the sphere boundary is .

[0125] The amplitude change of the reflected sound line is .

[0126] The phase change of the reflected sound is ,in is the complex reflection coefficient.

[0127] When solving the problem of sound wave propagation, the Eikonal equation and the paraxial ray equation can be solved by the Runge-Kutta method. In the calculation, we can adjust the step size in the numerical method to control the degree of discreteness in time and space to adapt to the speed and frequency characteristics of sound wave propagation. By adjusting the step size, the phase and amplitude of the sound wave can be fine-tuned to meet the reflection conditions. In actual calculations, it is necessary to iterate and adjust the step size repeatedly until the sound wave propagates in space and reflects a result that meets the conditions. By continuously optimizing the step size and parameters in the iterative process, the sound pressure value can meet the reflection conditions along a single ray beam, that is, the phase and amplitude of the sound wave meet the expected situation.

[0128] The solution to the equation is usually an approximation of the sound pressure value of the sound wave at a discrete space and time point, showing the process of sound wave propagation in space, the change of the sound field, and the interaction between the sound wave and the medium. The sound pressure of the ray beam can be obtained by combining the obtained solution of the equation with the interpolation method.

[0129] In one implementation of this embodiment, step S130, i.e., calculating the sound pressure contribution of the ray sound pressure at the real depth and distance grid, includes:

[0130] S500: Locate the endpoint distance between adjacent ray endpoints.

[0131] Specifically, the distance between the endpoints of the positioning ray is to determine the position of the receiving point on the sound wave propagation path. Once all the receiving points within the distance range are determined, these receiving points can be regarded as discrete coordinate points, and all the receiving points within the distance range can be converted to the ray center coordinates. .

[0132] S510, calculating non-ray endpoint values ​​based on endpoint distance and linear interpolation method.

[0133] Specifically, linear interpolation is a method that uses the straight line relationship between known data points to infer the values ​​at other locations. Based on the sound pressure values ​​at the two endpoints, the sound pressure values ​​at other points that are not at the endpoints can be solved. Calculate the values ​​to be calculated at non-ray endpoints through linear interpolation , , in is the proportional length along the ray segment, q is the external geometric extension, is the beam width parameter given by oneself, and τ is the phase.

[0134] S520: Obtain a receiving distance based on the non-ray endpoint value.

[0135] Specifically, the receiving distance is the normal distance between the receiving point and the ray endpoint, that is, n of the ray center coordinate.

[0136] S530: Determine whether the receiving distance is greater than the beam radius.

[0137] S540: If the receiving distance is greater than the beam radius, then calculate the sound pressure contribution of a single ray beam at the true depth and distance grid.

[0138] For a Gaussian beam, (The geometric beam is ), the receiving point contributes to the sound pressure field, where , looping through all ray endpoints, we can get the contribution of a sound ray to the sound field. After considering the caustic correction, the amplitude and sound pressure of the Gaussian beam generated by a single sound ray are:

[0139] .

[0140] .

[0141] The amplitude and sound pressure of the geometric sound beam generated by a single sound line are:

[0142]

[0143]

[0144] in, (r, z) is the amplitude, W is the half-width of the beam, It represents the serial number of the grazing angle, and P is the sound pressure.

[0145] By looping all sound lines, the sound pressure values ​​of all receiving points can be obtained.

[0146] .

[0147] In one implementation of this embodiment, step S140 obtains the grid sound pressure values ​​of all grid points according to the sound pressure contribution, including:

[0148] S600 . Obtain a sound pressure contribution value of each ray beam to the same grid point according to the sound pressure contribution of a single ray beam at a real depth and a distance grid.

[0149] S610 , accumulating the sound pressure contribution values ​​of all ray beams to the same grid point to obtain the grid point sound pressure value.

[0150] S620 , traverse all grid points to obtain grid sound pressure values ​​of all grid points.

[0151] Specifically, each grid point in the distance grid may be affected by multiple ray beams, thereby generating sound pressure contributions. Therefore, the sound pressure contribution value of each ray beam to the same grid point is calculated and superimposed to obtain the sound pressure value of the grid point. The sound pressure value of each grid point is then calculated in this way to obtain the grid sound pressure values ​​of all grid points.

[0152] In one implementation of this embodiment, step S150, i.e., the preset formula is:

[0153] The preset formula is:

[0154] ;

[0155] Among them, (r, z) is the receiving point, P is the grid sound pressure value, P0 is the sound intensity at a distance of 1m from the sound source, and TL (r, z) is the propagation loss of the receiving point.

[0156] like Figure 2 As shown, Figure 2 The sound propagation loss curve at a receiving depth of 200m: After considering the curvature of the earth, the sound propagation loss curve is generally offset toward the direction of the sound source, and the offset distance increases linearly. The offset at the 1000km sea surface convergence zone is 10km, indicating that the influence of the earth's curvature cannot be ignored. The error of the sound propagation loss calculated by the conformal mapping method gradually increases with the increase of the propagation distance. The propagation loss calculated by the method of the present invention at the 15th convergence zone (propagation distance of about 875km) is 96.2dB, and the propagation loss of the conformal mapping method is 100.5dB. The propagation loss of the convergence zone calculated by the method of the present invention is 4.3dB lower than that calculated by the conformal mapping method.

[0157] An ocean acoustic field calculation system, comprising:

[0158] The first building block is used to establish an isonic surface of seawater based on the effect of the earth's curvature.

[0159] The second building block is used to establish the Eidolon equation based on the seawater isosonic surface and environmental information.

[0160] The first calculation module is used to obtain the ray sound pressure of the ray beam based on the eikonal equation, the Jacobian field, the Jacobian equation and the correction step size.

[0161] The second calculation module is used to calculate the sound pressure contribution of the ray sound pressure at the real depth and distance grid.

[0162] The traversal module is used to obtain the grid sound pressure values ​​of all grid points according to the sound pressure contribution.

[0163] The third calculation module is used to input the grid sound pressure value into a preset formula to obtain the propagation loss of different receiving points.

[0164] The embodiment of the present application also discloses a terminal device, including a memory and a processor. The memory stores a computer program that can be run on the processor. When the processor loads and executes the computer program, a method for calculating the ocean sound field is adopted.

[0165] The terminal device may be a computer device such as a desktop computer, a laptop computer or a cloud server, and the terminal device includes but is not limited to a processor and a memory. For example, the terminal device may also include input and output devices, a network access device and a bus.

[0166] Among them, the processor can adopt a central processing unit (CPU). Of course, according to actual usage, other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. can also be adopted. The general-purpose processor can adopt a microprocessor or any conventional processor, etc., and this application does not impose any restrictions on this.

[0167] Among them, the memory can be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device, or it can be an external storage device of the terminal device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital card (SD) or a flash memory card (FC) equipped on the terminal device, and the memory can also be a combination of an internal storage unit and an external storage device of the terminal device. The memory is used to store computer programs and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or is to be output, and this application does not impose any restrictions on this.

[0168] Among them, through this terminal device, a method for calculating the ocean sound field in the above embodiment is stored in the memory of the terminal device, and is loaded and executed on the processor of the terminal device for easy use.

[0169] The embodiment of the present application further discloses a computer-readable storage medium, and the computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, a method for calculating an ocean acoustic field in the above embodiment is adopted.

[0170] Among them, the computer program can be stored in a computer-readable medium, the computer program includes computer program code, the computer program code can be in the form of source code, object code, executable file or certain middleware, etc. The computer-readable medium includes any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the computer-readable medium includes but is not limited to the above-mentioned components.

[0171] Among them, through this computer-readable storage medium, a method for calculating an ocean acoustic field in the above embodiment is stored in a computer-readable storage medium, and is loaded and executed on a processor to facilitate the storage and application of the above method.

[0172] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as above, which are not provided in detail for the sake of simplicity.

[0173] One or more embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A method for calculating ocean acoustic fields, characterized in that: include: Based on the effect of earth curvature, establish the constant sound velocity surface of seawater; Establishing an Eikonal equation based on the seawater isosonic surface and environmental information; Based on the eikonal equation, Jacobian field, Jacobian equation and correction step size, the ray sound pressure of the ray beam is obtained; Calculate the sound pressure contribution of the ray sound pressure at the real depth and distance grid; According to the sound pressure contribution, the grid sound pressure values ​​of all grid points are obtained; Inputting the grid sound pressure value into a preset formula to obtain the propagation loss at different receiving points; The obtaining of the ray sound pressure of the ray beam based on the eikonal equation, the Jacobian field, the Jacobian equation and the modified step size comprises: Based on the Eikonal equation and the Jacobian field, a cross-sectional curvature of the sound line is obtained; According to the cross-sectional curvature of the sound line, the Jacobi equation is obtained; According to the Jacobi equation and the modified step size, the ray sound pressure of the ray beam is obtained; The obtaining the ray sound pressure of the ray beam according to the Jacobi equation and the modified step size comprises: Get the initial value conditions and initial step size; Get reflection conditions; Adjust the initial step length based on the reflection condition to obtain the modified step length; Solving the eikonal equation and the Jacobi equation according to the initial conditions to obtain equation solutions; Based on the solution of the equation and the correction step size, obtaining the ray sound pressure of the ray beam; The calculation of the sound pressure contribution of the ray sound pressure at the real depth and distance grid includes: Locate the endpoint distance between adjacent ray endpoints; Calculating the non-ray endpoint value based on the endpoint distance and linear interpolation method; Obtaining a receiving distance based on the non-ray endpoint value; Determining whether the receiving distance is greater than the beam radius; If the receiving distance is greater than the beam radius, the acoustic pressure contribution of a single ray beam at the real depth and distance grid is calculated.

2. The ocean acoustic field calculation method according to claim 1, characterized in that: The establishing of the eikonal equation based on the seawater isosonic surface and environmental information comprises: Acquire the propagation distance and the propagation depth based on the environmental information; Based on the propagation distance and the propagation depth, a sound velocity profile is obtained; According to the sound velocity profile, a Riemann metric of propagation time under the effect of earth curvature is established; Based on the Riemann metric and the geodesic equation, the eikonal equation is obtained.

3. The ocean acoustic field calculation method according to claim 1, characterized in that: The grid sound pressure values ​​of all grid points are obtained according to the sound pressure contribution, including: According to the sound pressure contribution of a single ray beam at the real depth and distance grid, obtaining the sound pressure contribution value of each ray beam to the same grid point; Accumulating the sound pressure contribution values ​​of all ray beams to the same grid point to obtain the grid point sound pressure value; All grid points are traversed to obtain the grid sound pressure values ​​of all grid points.

4. The ocean acoustic field calculation method according to claim 1, characterized in that: The preset formula is: ； Among them, (r, z) is the receiving point, is the grid sound pressure value, is the sound intensity at a distance of 1m from the sound source, TL(r,z) is the propagation loss at the receiving point, r is the propagation distance, and z is the depth.

5. An ocean acoustic field calculation system, characterized in that: include: The first building module is used to establish the seawater constant sound velocity surface based on the earth curvature effect; A second building block is used to establish an eikonal equation based on the seawater isosonic surface and environmental information; A first calculation module, used for obtaining the ray sound pressure of the ray beam based on the eikonal equation, the Jacobian field, the Jacobian equation and the correction step size; A second calculation module is used to calculate the sound pressure contribution of the ray sound pressure at the real depth and distance grid; A traversal module is used to obtain the grid sound pressure values ​​of all grid points according to the sound pressure contribution; A third calculation module is used to input the grid sound pressure value into a preset formula to obtain the propagation loss of different receiving points; The obtaining of the ray sound pressure of the ray beam based on the eikonal equation, the Jacobian field, the Jacobian equation and the modified step size comprises: Based on the Eikonal equation and the Jacobian field, a cross-sectional curvature of the sound line is obtained; According to the cross-sectional curvature of the sound line, the Jacobi equation is obtained; According to the Jacobi equation and the modified step size, the ray sound pressure of the ray beam is obtained; The obtaining the ray sound pressure of the ray beam according to the Jacobi equation and the modified step size comprises: Get the initial value conditions and initial step size; Get reflection conditions; Adjust the initial step length based on the reflection condition to obtain the modified step length; Solving the eikonal equation and the Jacobi equation according to the initial conditions to obtain equation solutions; Based on the solution of the equation and the correction step size, obtaining the ray sound pressure of the ray beam; The calculation of the sound pressure contribution of the ray sound pressure at the real depth and distance grid includes: Locate the endpoint distance between adjacent ray endpoints; Calculating the non-ray endpoint value based on the endpoint distance and linear interpolation method; Obtaining a receiving distance based on the non-ray endpoint value; Determining whether the receiving distance is greater than the beam radius; If the receiving distance is greater than the beam radius, the acoustic pressure contribution of a single ray beam at the real depth and distance grid is calculated.

6. A terminal device, comprising a memory and a processor, characterized in that: The memory stores a computer program that can be run on the processor, and when the processor loads and executes the computer program, the computing method according to any one of claims 1 to 4 is adopted.

7. A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, characterized in that: When the computer program is loaded and executed by a processor, the computing method according to any one of claims 1 to 4 is adopted.

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