Fast prediction method and device of vector sound field based on ray theory

Abstract

The application relates to a vector sound field fast prediction method and device based on ray theory and relates to the technical field of underwater acoustics. In order to solve the problems that the differential method prediction causes the increase of calculation amount, the reduction of calculation efficiency and the superposition method causes the reduction of the precision of particle velocity prediction in the prior art, the technical scheme is as follows: the vector sound field fast prediction method based on ray theory comprises the following steps: collecting preset marine parameters, sound source parameters and receiver parameters, obtaining the sound ray track from the sound source to the receiver and the time delay parameters corresponding to the track points on the track according to the parameters; obtaining the sound beam equation of the sound ray emitted at a preset grazing angle from a to-be-simulated point according to the sound ray track and the time delay parameters; obtaining the particle velocity of the to-be-simulated point in the tangent direction of the sound ray track according to the sound beam equation; and obtaining the sound pressure, the particle velocity in the horizontal direction and the particle velocity in the vertical direction of the to-be-simulated point according to the sound beam equation, the particle velocity and the sound ray track. The application is suitable for the work of the vector sound field fast prediction.

Description

TECHNICAL FIELD

[0001] The application relates to the field of underwater acoustic physics, and in particular to a fast prediction method for a vector sound field. BACKGROUND

[0002] With the development of vector hydrophone technology, various direction-finding and positioning methods based on vector hydrophones emerge in endlessly, and the research on the prediction method of the vector sound field is the basis for developing the positioning and detection methods based on the vector hydrophone and is of great significance.

[0003] The scholars at home and abroad mainly adopt two methods for predicting the vector sound field: one is to perform differential operation on sound pressure in different directions according to the connection between the sound pressure and the particle velocity, that is, the Euler formula, and then obtain the particle velocity in different directions; and the other is to assume that the sound pressure of a receiving point is the superposition between a direct wave and a once-reflected wave on the sea surface, and then calculate the particle velocity in different directions of the receiving point according to the Euler formula and the arrival angle of the sound ray. However, the two methods have the following defects: the particle velocity predicted by the differential method is related to the grid size, the finer the grid, the higher the prediction accuracy of the particle velocity, but this often causes an increase in the calculation amount and a reduction in the calculation efficiency; and the superposition method simplifies the calculation of the sound pressure of the receiving point and ignores the incoming waves in other directions, which reduces the prediction accuracy of the particle velocity. SUMMARY

[0004] In order to solve the problems in the prior art that the particle velocity predicted by the differential method is related to the grid size, the finer the grid, the higher the prediction accuracy of the particle velocity, but this often causes an increase in the calculation amount and a reduction in the calculation efficiency, and the superposition method simplifies the calculation of the sound pressure of the receiving point and ignores the incoming waves in other directions, which reduces the prediction accuracy of the particle velocity, the technical scheme provided by the application is as follows:

[0005] The fast prediction method for the vector sound field based on the ray theory comprises the following steps:

[0006] Step 1: collecting preset ocean parameters, sound source parameters and parameters of a receiver, obtaining the sound ray trajectory from the sound source to the receiver and the time delay parameters corresponding to the trajectory points on the trajectory according to the parameters;

[0007] Step 2: obtaining the sound beam equation of the sound ray emitted from a to-be-simulated point at a preset grazing angle according to the sound ray trajectory and the time delay parameters;

[0008] Step 3: obtaining the particle velocity of the to-be-simulated point along the tangent direction of the sound ray trajectory according to the sound beam equation;

[0009] Step 4: obtaining the sound pressure of the to-be-simulated point and the particle velocities in the horizontal and vertical directions according to the sound beam equation, the particle velocity and the sound ray trajectory.

[0010] Further, a preferred embodiment is provided, wherein in the step 1, the time delay parameter is obtained by dynamic tracking.

[0011] Further, a preferred embodiment is provided, wherein the sound ray trajectory is obtained by Runge-Kutta method.

[0012] Further, a preferred embodiment is provided, wherein in the step 2, the sound beam equation is obtained by constructing a Gaussian sound beam on both sides of the sound ray trajectory with the sound ray trajectory as the center, and the sound beam equation is obtained by the Gaussian sound velocity.

[0013] Further, a preferred embodiment is provided, wherein in the step 3, the particle vibration velocity is obtained according to Euler formula.

[0014] Further, a preferred embodiment is provided, wherein in the step 4, the arrival angle of the sound ray emitted by the to-be-simulated point at different grazing angles is obtained by obtaining the tangent of the sound ray trajectory, the direction of the particle vibration velocity is obtained, and the sound pressure, the horizontal and vertical particle vibration velocities of the to-be-simulated point are obtained according to the direction of the particle vibration velocity.

[0015] Based on the same inventive concept, the application further provides a ray theory-based vector sound field fast prediction device, which comprises:

[0016] Module 1: used for collecting preset marine parameters, sound source parameters and receiver parameters, obtaining a sound ray trajectory from the sound source to the receiver and a time delay parameter corresponding to a trajectory point on the trajectory according to the parameters;

[0017] Module 2: used for obtaining a sound beam equation of a sound ray emitted by a to-be-simulated point at a preset grazing angle according to the sound ray trajectory and the time delay parameter;

[0018] Module 3: used for obtaining a particle vibration velocity of the to-be-simulated point along the tangent direction of the sound ray trajectory according to the sound beam equation;

[0019] Module 4: used for obtaining a sound pressure, a horizontal particle vibration velocity and a vertical particle vibration velocity of the to-be-simulated point according to the sound beam equation, the particle vibration velocity and the sound ray trajectory.

[0020] Further, a preferred embodiment is provided, wherein in the module 1, the time delay parameter is obtained by dynamic tracking, and the sound ray trajectory is obtained by Runge-Kutta method.

[0021] Computer storage medium for storing a computer program, wherein the computer program is used to be read by a computer to execute the fast prediction method of vector sound field based on ray theory.

[0022] Computer comprising a processor and a storage medium, wherein the storage medium stores a computer program, and wherein the computer program is used to be read by the processor to make the computer execute the fast prediction method of vector sound field based on ray theory.

[0023] Compared with the prior art, the present application has the advantages of:

[0024] The fast prediction method of vector sound field based on ray theory provided by the present application is used to solve the problems of large amount of calculation, low calculation efficiency and strong correlation between calculation accuracy and grid division size in the prior art vector sound field calculation method.

[0025] The fast prediction method of vector sound field based on ray theory provided by the present application has high calculation efficiency and sufficient calculation accuracy, and can realize fast prediction of vector sound field.

[0026] The present application is suitable for fast prediction of vector sound field. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A schematic diagram of deep-sea Munk sound speed profile mentioned in the eleventh embodiment;

[0028] Figure 2 A schematic diagram of ship loss distribution of vector sound field predicted by ray theory mentioned in the eleventh embodiment;

[0029] Figure 3 A schematic diagram of propagation loss curve of 1000m receiving depth mentioned in the eleventh embodiment. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] The present application will be further described in combination with specific embodiments and drawings:

[0032] Embodiment one, the present embodiment provides a fast prediction method of vector sound field based on ray theory, the method comprises:

[0033] Step 1: collecting preset marine parameters, sound source parameters and receiver parameters, obtaining a sound ray trajectory from the sound source to the receiver according to the parameters, and a time delay parameter corresponding to a trajectory point on the trajectory;

[0034] Step 2: obtaining a sound beam equation of a sound ray emitted from a to-be-simulated point at a preset grazing angle according to the sound ray trajectory and the time delay parameter;

[0035] Step 3: obtaining a particle vibration velocity of the to-be-simulated point in a tangential direction of the sound ray trajectory according to the sound beam equation;

[0036] Step 4: obtaining sound pressure, particle vibration velocities in horizontal and vertical directions of the to-be-simulated point according to the sound beam equation, the particle vibration velocity and the sound ray trajectory.

[0037] The marine hydrological environment parameter model comprises a distance-independent / dependent environment sound velocity profile, seawater density, seabed topography parameters and sediment layer parameters, i.e., a marine parameter model applicable to the ray theory;

[0038] The seabed parameter model comprises distance-independent / dependent environment seabed topography and sediment layer parameters, i.e., a seabed parameter model applicable to the ray theory.

[0039] Embodiment two, the embodiment is a further limitation of the vector sound field fast prediction method based on the ray theory provided in embodiment one, and in the step 1, the manner of obtaining the time delay parameter is specifically: through a dynamic tracking manner.

[0040] Embodiment three, the embodiment is a further limitation of the vector sound field fast prediction method based on the ray theory provided in embodiment two, and the manner of obtaining the sound ray trajectory is: through a Runge-Kutta method.

[0041] Specifically, according to the given marine hydrological environment parameter model, the seabed parameter model and the parameters of the sound source and the receiver, dynamic ray tracing is performed, and a sound ray trajectory [r(s), z(s)] from the sound source to the receiver and a time delay τ(s) and parameters p(s) and q(s) related to a sound ray amplitude corresponding to each trajectory point on the sound ray are calculated.

[0042] The sound ray trajectory [r(s), z(s)] can be obtained by repeatedly solving the following equation set through a Runge-Kutta method,

[0043]

[0044] where c(s) is the sound speed at s, ζ(s), ξ(s) are auxiliary variables defined, dr represents the step size in the horizontal direction, ds represents the step size along the sound ray trajectory, dξ / dz, dζ / ds represent the derivatives of the auxiliary variables [ξ, ζ] along the sound ray trajectory direction constructed for solving the sound ray trajectory, represents the derivative of the sound speed c in the distance direction, represents the derivative of the sound speed c in the depth direction.

[0045] The time delay τ(s) can be obtained by the following integral formula:

[0046]

[0047] where τ(0) represents the initial time delay, s represents the sound ray trajectory, c(s') represents the sound speed at any point on the sound ray trajectory, and ds' represents the step size along the sound ray trajectory.

[0048] The parameters p(s), q(s) related to the sound ray amplitude are the solutions of the dynamic ray equation:

[0049]

[0050] where c nn (s) is the sound speed curvature in the direction of the vertical ray path.

[0051] Embodiment four, this embodiment is a further limitation of the vector sound field fast prediction method based on ray theory provided in embodiment one, in step 2, the manner of obtaining the sound beam equation is specifically: constructing a Gaussian sound beam on both sides of the sound ray trajectory with the sound ray trajectory as the center, and obtaining the sound beam equation through the Gaussian sound speed.

[0052] Specifically, according to the sound ray trajectory [r(s), z(s)], the time delay τ(s) and the parameters p(s), q(s) related to the sound ray amplitude obtained in step 1, and in order to map the sound field calculated in the ray coordinate system to the rectangular grid defined by the user, a Gaussian sound beam is constructed on both sides of the sound ray with the sound ray trajectory as the center, and the sound beam equation of the sound ray emitted at the grazing angle α can be obtained:

[0053]

[0054] where Amp represents a constant related to the sound source parameters, c(s) represents the sound speed at the [r(s), z(s)] position, n represents the vertical distance from the center ray, W(s) represents the beam width of the Gaussian beam, and the beam width j represents the imaginary unit, and phaseInt represents the phase correction.

[0055] Implementation Method 5: This implementation method further defines the vector sound field rapid prediction method based on ray theory provided in Implementation Method 1. In step 3, the particle velocity is obtained specifically by using Euler's formula.

[0056] Specifically, according to Euler's formula The magnitude of the particle velocity along the tangent to the ray trajectory can be determined:

[0057]

[0058] Where beam represents the beam, a represents the angle of arrival of the sound ray, and du / dt represents the time derivative of the particle velocity u. denoted by , j represents the imaginary unit, ω represents the angular frequency, and ρ0 represents the density of the medium. It represents the derivative of sound pressure along the trajectory of the sound ray.

[0059] Based on the sound beam equation for a single sound ray in step two, the sound beam equation corresponding to the particle velocity can be obtained as follows:

[0060]

[0061] Implementation Method Six: This implementation method further defines the vector sound field rapid prediction method based on ray theory provided in Implementation Method One. In step 4, the arrival angle of the sound rays emitted from the simulated point at different grazing angles is obtained by finding the tangent of the sound ray trajectory, and the direction of the particle velocity is obtained. Based on the direction of the particle velocity, the sound pressure and the particle velocity in the horizontal and vertical directions of the simulated point are obtained.

[0062] Based on the sound beam equation obtained in step two and the sound beam equation for particle velocity obtained in step three, the complex sound pressure and particle velocity at position (r,z) can be obtained. Based on the ray trajectory obtained from ray tracing in step one, different grazing angles α can be calculated by finding the tangent to the sound ray trajectory. i The angle of arrival θ of the emitted sound ray at this location i , which represents the direction of the particle velocity. Therefore, the sound pressure at any point (r, z) in the sound field, and the particle velocities in the horizontal and vertical directions can be obtained by the following formula:

[0063]

[0064] in Represents the i-th exit angle α i The corresponding beam mapping is the complex sound pressure at grid point (r,z). Represents the i-th exit angle α iThe corresponding beam mapping particle velocity at the grid point (r,z), i represents the i-th ray tracing, N represents the number of ray tracing, p(r,z) represents the sound pressure, u r (r,z) represents the horizontal particle velocity, u z (r,z) represents the vertical particle velocity.

[0065] Therefore, the sound pressure propagation loss, the horizontal and vertical particle velocity propagation loss of any point (r,z) in the sound field can be obtained by the following formula:

[0066]

[0067] wherein is the reference sound pressure, is the particle velocity reference value, k0 represents the reference wave number, r represents the horizontal distance, TL p represents the sound pressure propagation loss, represents the horizontal particle velocity propagation loss, represents the vertical velocity propagation loss.

[0068] Embodiment seven, the embodiment provides a fast prediction device of vector sound field based on ray theory, and the device comprises:

[0069] Module 1: used for collecting preset marine parameters, sound source parameters and parameters of a receiver, obtaining a sound ray track from the sound source to the receiver and time delay parameters corresponding to track points on the track according to the parameters;

[0070] Module 2: used for obtaining a sound beam equation of a sound ray emitted at a preset grazing angle from a point to be simulated according to the sound ray track and the time delay parameters;

[0071] Module 3: used for obtaining particle velocity of the point to be simulated in the tangential direction of the sound ray track according to the sound beam equation;

[0072] Module 4: used for obtaining sound pressure, horizontal and vertical particle velocity of the point to be simulated according to the sound beam equation, particle velocity and the sound ray track.

[0073] Embodiment eight, the embodiment is a further limitation of the fast prediction device of vector sound field based on ray theory provided by the embodiment seven, and in the module 1, the time delay parameters are obtained by a dynamic tracking mode; the sound ray track is obtained by a Runge-Kutta method.

[0074] Embodiment nine, the embodiment provides a computer storage medium for storing a computer program, the computer program is read by a computer to execute the ray theory based fast prediction method of vector sound field provided in any one of the embodiments one to six.

[0075] Embodiment ten, the embodiment provides a computer including a processor and a storage medium, the storage medium stores a computer program, characterized in that the computer program is read by the processor, so that the computer executes the ray theory based fast prediction method of vector sound field provided in any one of the embodiments one to six.

[0076] Embodiment eleven, the embodiment is a specific embodiment of the ray theory based fast prediction method of vector sound field provided in the embodiment one, and is used to verify the advantages and benefits of the method, in particular:

[0077] For the typical sound velocity profile Munk profile in deep sea, the sound velocity expression of Munk profile is:

[0078] c(z)=c0{1+ε[e -η -(1-η)]};

[0079] Wherein, η=2(z-z0) / B, z represents the depth of seawater, z0 is the depth of sound channel axis, B is the width of waveguide, c0 is the minimum sound velocity, ε is the magnitude of deviation from the minimum value, and η represents the scaled depth.

[0080] For the typical Munk model, the parameters are: B=1000m, z0=1000m, c0=1500m / s, ε=0.57×10 -2 The sound velocity profile is shown in Figure 1 .

[0081] The sound source depth is 1000m, the environment with a depth of 5000m is selected for simulation, the frequency is 100Hz, the prediction distance is 200km, the ray tracing is performed according to the given marine environment parameters, then the sound pressure, the horizontal direction particle velocity and the vertical direction particle velocity are calculated according to the formula (4), (6), (7), the calculated vector sound field propagation loss distribution diagram is shown in Figure 2 , and the calculated propagation loss curve at the receiving depth of 1000m is shown in Figure 3 .

[0082] The technical solutions of the present application are described in further detail through several specific embodiments above, in order to highlight the advantages and benefits of the technical solutions provided by the present application. However, the above several specific embodiments are not used as a limitation to the present application, and any reasonable modifications and improvements, reasonable combinations and equivalent replacements of the embodiments, etc. based on the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A fast prediction method of vector acoustic field based on ray theory, characterized in that, The method comprises: Step 1: collecting preset marine parameters, sound source parameters and receiver parameters, obtaining a sound ray track from the sound source to the receiver according to the parameters and a time delay parameter corresponding to a track point on the track; Step 2: obtaining a sound beam equation of a sound ray emitted from a to-be-simulated point at a preset grazing angle according to the sound ray track and the time delay parameter; Step 3: obtaining a particle vibration velocity of the to-be-simulated point along a tangent direction of the sound ray track according to the sound beam equation; Step 4: obtaining sound pressure, horizontal and vertical particle vibration velocities of the to-be-simulated point according to the sound beam equation, the particle vibration velocity and the sound ray track; The marine hydrological environmental parameter model comprises a distance-independent / dependent environmental sound velocity profile, seawater density, seabed topography parameters and sediment layer parameters, i.e. a marine parameter model applicable to the ray theory; The seabed parameter model comprises distance-independent / dependent environmental seabed topography and sediment layer parameters, i.e. a seabed parameter model applicable to the ray theory.

2. The fast ray-theory-based vector acoustic field prediction method of claim 1, wherein, In the step 1, the time delay parameter is obtained by means of dynamic tracking.

3. The fast ray-theory-based vector acoustic field prediction method of claim 2, wherein, The sound ray track is obtained by means of the Runge-Kutta method.

4. The fast ray-theory-based vector acoustic field prediction method of claim 1, wherein, In the step 2, the sound beam equation is obtained by constructing a Gaussian sound beam on both sides of the sound ray track with the sound ray track as the center and by obtaining the sound beam equation through the Gaussian sound beam.

5. The fast ray-theory-based vector acoustic field prediction method of claim 1, wherein, In the step 3, the particle vibration velocity is obtained according to the Euler formula.

6. The fast ray-theory-based vector acoustic field prediction method of claim 1, wherein, In the step 4, the arrival angle of a sound ray emitted from the to-be-simulated point at different grazing angles at the to-be-simulated point is obtained by solving a tangent of the sound ray track, the direction of the particle vibration velocity is obtained, and the sound pressure, horizontal and vertical particle vibration velocities of the to-be-simulated point are obtained according to the direction of the particle vibration velocity.

7. A device for fast prediction of vector acoustic field based on ray theory, characterized in that, The device comprises: Module 1: configured to collect preset marine parameters, sound source parameters and receiver parameters, and obtain a sound ray track from the sound source to the receiver and a time delay parameter corresponding to a track point on the track according to the parameters; Module 2: configured to obtain a sound beam equation of a sound ray emitted from a to-be-simulated point at a preset grazing angle according to the sound ray track and the time delay parameter; Module 3: configured to obtain a particle vibration velocity of the to-be-simulated point along a tangent direction of the sound ray track according to the sound beam equation; Module 4: configured to obtain sound pressure, horizontal and vertical particle vibration velocities of the to-be-simulated point according to the sound beam equation, the particle vibration velocity and the sound ray track; The marine hydrological environmental parameter model comprises a distance-independent / dependent environmental sound velocity profile, seawater density, seabed topography parameters and sediment layer parameters, i.e. a marine parameter model applicable to the ray theory; The seabed parameter model comprises distance-independent / dependent environmental seabed topography and sediment layer parameters, i.e. a seabed parameter model applicable to the ray theory.

8. The device for fast prediction of vector sound field based on ray theory according to claim 7, characterized in that, In the module 1, the time delay parameter is obtained by means of dynamic tracking, and the sound ray track is obtained by means of the Runge-Kutta method.

9. Computer storage medium for storing a computer program, characterized in that The computer program is configured to be read by a computer to execute the ray theory-based fast prediction method of a vector sound field according to any one of claims 1-6.

10. A computer comprising a processor and a storage medium, said storage medium having stored therein a computer program, characterized in that, The computer program is used for being read by the processor, and the computer executes the fast prediction method of the vector sound field based on the ray theory according to any one of claims 1-6.

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