Underwater target matching field positioning method and system of fusion convergence zone sound intensity gain

Abstract

The application provides an underwater target matching field positioning method and system fusing sound intensity gain of a convergence zone, sets deployment parameters of an underwater sound source in a target sea area, including sound source depth, exit angle range and frequency, and deploys a sonar listener in a first convergence zone to generate simulation parameters; based on the simulation parameters and sea area sound velocity profile data, a layered sound velocity modeling and sound ray propagation model are used to calculate distance, width and convergence zone gain of the first convergence zone formed by the target sound source, and convergence zone characteristic parameters are obtained; the convergence zone characteristic parameters and the simulation parameters are input into a Bellhop sound field modeling tool to obtain simulated sound intensity data including a propagation path and propagation loss; the simulated sound intensity data and measured sound intensity data of the sonar listener are compared to construct a cost function; a horizontal distance between the estimated target sound source and the sonar listener is obtained by maximizing the cost function, so that the positioning of the underwater target is completed.

Description

Technical Field

[0001] This invention relates to the field of underwater positioning technology, specifically to an underwater target matching field positioning method and system that integrates the acoustic intensity gain of the convergence zone. Background Technology

[0002] In applications such as deep-sea monitoring, marine engineering, and resource exploration, underwater acoustic source target localization technology plays a crucial role in deep-sea environments. Especially in the context of deep-sea convergence zones, sound waves undergo nonlinear bending and periodic focusing during propagation due to changes in the sound velocity gradient, resulting in a concentration of sound energy within a certain distance area—the convergence zone. While this phenomenon can enhance long-distance signal reception, it also significantly increases the complexity of the sound field structure, affecting the accurate calculation of sound source distance and orientation information. Therefore, in-depth research into the physical characteristics of convergence zones and their impact on sound propagation behavior is an important prerequisite for improving target localization accuracy in deep-sea environments.

[0003] To meet the dual requirements of concealment and accuracy in underwater positioning, existing technologies commonly employ Matched Field Processing (MFP) for target location estimation. This method utilizes known marine environmental parameters to construct a sound propagation model, calculates a reference sound field in a specific scenario, and performs similarity matching between this reference field and the measured signal from a listening device, thereby retrieving the location of the target sound source. The MFP method fully leverages multipath propagation information and has been widely applied in shallow sea and regular sound channel environments.

[0004] However, traditional MFP methods have significant limitations under the complex acoustic field conditions of deep-sea convergence zones. On the one hand, existing models are mostly based on simplified or uniform sound velocity profiles, which cannot accurately describe the focusing and bending behavior of sound waves under the layered and non-uniform sound velocity structure of the deep sea. On the other hand, they do not effectively consider the spatial distribution characteristics of sound intensity gain in the convergence zone, leading to a decrease in matching accuracy. In addition, the coupling relationship between the sonar listener and the location of the convergence zone is not modeled or utilized, further limiting the system's target detection capability in complex long-range environments. Therefore, there is an urgent need for a target localization method that takes into account both the modeling of convergence zone characteristics and actual sound intensity observations to achieve high-precision matching field localization of deep-sea targets. Summary of the Invention

[0005] This invention proposes an underwater target matching field localization method and system that integrates the acoustic intensity gain of the convergence zone to solve the technical problem of low accuracy of existing localization methods under complex acoustic field conditions in the deep sea convergence zone.

[0006] To address the aforementioned technical problems, this invention provides an underwater target matching field localization method that integrates the acoustic intensity gain of the convergence region, comprising the following steps:

[0007] Step S1, Simulation Scenario Configuration: Set the deployment parameters of underwater sound sources in the target sea area, including sound source depth, emission angle range and frequency, and deploy sonar listeners in the first convergence zone to generate simulation parameters;

[0008] Step S2, Deep-sea convergence zone characteristic analysis: Based on the simulation parameters and sea area sound velocity profile data, using layered sound velocity modeling and sound ray propagation model, the distance, width and convergence zone gain of the first convergence zone formed by the target sound source are calculated to obtain the convergence zone characteristic parameters;

[0009] Step S3, Bellhop sound field modeling: Input the convergence zone characteristic parameters and the simulation parameters into the Bellhop sound field modeling tool to obtain simulated sound intensity data including propagation path and propagation loss;

[0010] Step S4, target matching field localization modeling: compare the simulated sound intensity data with the measured sound intensity data of the sonar listener, and construct a cost function;

[0011] Step S5, target distance estimation: By maximizing the cost function, the estimated horizontal distance between the target sound source and the sonar listener is obtained, thereby completing the underwater target localization.

[0012] Preferably, the distance of the first convergence zone is calculated based on the relationship between the sound ray exit angle and the interlayer sound velocity gradient; the width of the first convergence zone is calculated by the difference in the horizontal distance of the sound ray under the maximum and minimum incident angles; and the gain of the first convergence zone is derived based on the sound field eigenfunctions and Hermitian functions in wave theory.

[0013] Preferably, in step S2, the method for calculating the distance of the first convergence region includes:

[0014] Step S211: Based on the sound speed gradient, divide the water body from the sea surface to the seabed into several layers;

[0015] Step S212: Calculate the horizontal distance traveled by the sound ray in each layer during the first bend. Its expression is:

[0016] ;

[0017] In the formula, Indicates the vocal timbre at the 1st position. The horizontal distance traversed by the layer; For the first Layer sound velocity gradient; Indicates the emission angle of the first layer as The corresponding feature parameters; Indicates the first The speed of sound in the layer; Indicates the number of layers;

[0018] Step S213: Let the emission angle of the other sound ray be... , Its corresponding horizontal distance is Using the first sound ray as a reference, a Taylor expansion of the horizontal distance with respect to the angle is performed to obtain the change in horizontal distance. The expression is:

[0019] ;

[0020] In the formula, Indicates the emission angle of the first layer as It is the corresponding number The horizontal distance traversed by the layer Indicates the first The change in the horizontal distance traversed by the layer; Indicates the glancing angle;

[0021] Step S214: When At that time, the sonar listener was set to the position of the first... Layer, and with the first The distance from the upper boundary of the layer is Calculate the distance to the convergence zone for:

[0022] ;

[0023] ;

[0024] In the formula, It is the voice from the first The upper boundary of the layer propagates to the horizontal distance of the sonar listener; It is the speed of sound at the depth where the sonar receiver is located.

[0025] Preferably, in step S2, the method for calculating the width of the first convergence region includes:

[0026] Step S221: Set the incident angle to 0 and calculate the maximum convergence zone distance. :

[0027] ;

[0028] In the formula, and These represent the average sound velocity gradients along and below the vocal tract axis; The velocity of sound along the axial direction of the vocal tract; The speed of sound at the first level, starting from sea level;

[0029] Step S222: Set the angle of incidence as the maximum angle of incidence. Calculate the minimum convergence distance :

[0030] ;

[0031] Step S223: Subtract the minimum convergence distance from the maximum convergence distance to obtain the width of the first convergence region.

[0032] Preferably, the convergence region gain in step S2 The expression is:

[0033] ;

[0034] In the formula, The assembly zone number; Intervals between convergence zones; Indicates wave number; Represents the convergence function; and The depths of the underwater sound source and the sonar receiver are respectively. These are the parameters of the parabola.

[0035] Preferably, the cost function described in step S4 The expression is:

[0036] ;

[0037] In the formula, The number of sound ray intensities selected within the convergence zone; This represents the lower limit of the convergence zone distance; This represents the upper limit of the convergence zone distance; Sound intensity; The sound intensity measurement value of the sonar listener; This indicates the horizontal distance between the candidate target sound source and the listener.

[0038] The present invention also provides an underwater target matching field localization system that integrates the acoustic intensity gain of the convergence region, applicable to the above-mentioned method, comprising:

[0039] The simulation configuration module is used to set the deployment parameters of underwater sound sources in the target sea area, including the depth, emission angle range and frequency of the sound sources, and to configure the deployment parameters of the sonar listener at the first convergence zone position to generate simulation parameters.

[0040] The convergence zone analysis module is used to calculate the distance, width and convergence zone gain of the first convergence zone formed by the sound source based on the simulation parameters and the sea area sound velocity profile data, using a layered sound velocity model and a sound ray propagation model, and to obtain the convergence zone characteristic parameters.

[0041] The sound field modeling module is used to input the convergence zone characteristic parameters and the simulation parameters into the Bellhop sound field modeling tool, simulate the sound wave propagation path based on the ray tracing method, and obtain simulated sound intensity data including the propagation path and propagation loss.

[0042] The data acquisition module is used to acquire measured sound intensity data collected by sonar listeners deployed in the first convergence zone;

[0043] The positioning processing module is used to compare the simulated sound intensity data with the measured sound intensity data, construct a cost function, and estimate the horizontal distance between the target sound source and the sonar listener by solving for the maximum value of the cost function, thereby realizing the matching field positioning of the underwater target.

[0044] This invention proposes an underwater target matching field localization method based on the Bellhop sound field model. It fully considers the complex propagation characteristics of the deep-sea converging environment, such as sound velocity non-uniformity, sound ray bending, and multipath focusing, overcoming the problem of insufficient localization accuracy of traditional matching field methods in this environment. Compared with existing technologies, this invention has at least the following advantages:

[0045] By introducing realistic layered sound velocity profiles and physical modeling of the convergence zone, and through quantitative analysis of the convergence zone distance, width, and sound intensity gain of the target sea area, the sound field construction process is made closer to the actual underwater acoustic environment, avoiding the misjudgment of the actual propagation path by the smooth ideal model in traditional methods.

[0046] By integrating the Bellhop ray tracing sound field modeling tool, it can efficiently calculate the propagation loss and sound ray trajectory under various paths in complex marine environments, accurately reconstruct the multipath signal structure received by the listener in the convergence zone, and provide accurate simulated sound intensity data support for subsequent matching processing.

[0047] By combining the measured sound intensity from the listener with the modeled sound intensity to construct a cost function, the horizontal distance to the target is estimated by maximizing the correlation. This approach does not rely on a multi-dimensional grid search method, effectively reducing computational complexity and improving the convergence efficiency and robustness of the localization process.

[0048] The system has a clear structure and tight coupling between modules, which not only improves the accuracy of sound source localization in complex deep-sea environments, but also enhances the system's adaptability to changes in sound source frequency, emission angle and deployment depth, making the underwater target localization system more practical and flexible.

[0049] In summary, this invention has made substantial improvements to existing underwater matching field positioning technology in terms of modeling accuracy, data utilization efficiency, and system adaptability. It is particularly suitable for high-precision positioning of remote underwater sound sources in complex marine environments such as deep-sea convergence zones, and has good engineering application value and promotion prospects. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of a sea area in an underwater target positioning simulation scenario according to an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram illustrating the relationship between the probability of convergence and depth in an embodiment of the present invention.

[0053] Figure 4 This is a schematic diagram of a simulation scenario according to an embodiment of the present invention;

[0054] Figure 5 This is a schematic diagram of the deep-sea sound velocity profile according to an embodiment of the present invention;

[0055] Figure 6 This is a schematic diagram of the sound propagation path and sound propagation loss according to an embodiment of the present invention;

[0056] Figure 7 This is a schematic diagram of the sound source localization results at different sound source depths based on the multipath propagation method of acoustic signals according to an embodiment of the present invention;

[0057] Figure 8 This is a schematic diagram of the sound source localization results at different sound source depths according to an embodiment of the present invention.

[0058] Figure 9 This is a schematic diagram showing the comparison results of the matching field processing in an embodiment of the present invention. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0060] like Figure 1 As shown, this embodiment of the invention provides an underwater target matching field localization method that integrates the acoustic intensity gain of the convergence region, including the following steps:

[0061] Step S1, Simulation Scenario Configuration: Set the deployment parameters of underwater sound sources in the target sea area, including sound source depth, emission angle range and frequency, and deploy sonar listeners in the first convergence zone to generate simulation parameters.

[0062] In this embodiment, the simulated underwater sound source target localization scenario is located in a deep-sea basin, such as... Figure 2 As shown.

[0063] The maximum depth in this sea area can reach 5500m, with a depth margin of over 900m. According to... Figure 3 The curve showing the relationship between average depth margin and the probability of convergence zone occurrence indicates that the probability of convergence zone phenomenon in this sea area can reach over 85%. In this context, to study the actual detection effect of a seabed listening array on specific underwater targets in real-world situations, a simulated underwater target sound source deployment depth of 150m–200m, a sound source frequency of 1000Hz, and a sound source emission angle of -15°–15° were used. The sonar listener was deployed at the first convergence zone location, effectively acquiring the sound signal gain in the convergence zone. The simulation scenario is as follows: Figure 4 As shown.

[0064] Step S2, Deep-sea Convergence Zone Characteristic Analysis: Based on simulation parameters and sea area sound velocity profile data, layered sound velocity modeling and sound ray propagation model are used to calculate the distance, width, and convergence zone gain of the first convergence zone formed by the target sound source, and obtain the convergence zone characteristic parameters.

[0065] (1) Distance of the convergence zone

[0066] As the sound source propagates, the convergence zones formed are successively called the first convergence zone, the second convergence zone, etc., from near to far. The signal gain brought by the convergence zone is the greatest in the first convergence zone, and the study of the distance of the convergence zone generally refers to the distance of the first convergence zone.

[0067] The speed of sound changes relatively slowly with depth, dividing the area into multiple layers, with the speed gradient of each layer considered constant. In this case, the propagation path of sound rays in different layers is an arc when the speed gradient is not zero, and a straight line when the speed gradient is zero, i.e., in a uniform layer.

[0068] Let the sound speed distribution be... Layers, each layer is [width value missing] , No. The sound velocities of the layer above it and the layer above it are respectively and ( The first layer begins at sea level, with a sound speed of... , No. The layer ends at the seabed. Based on the simulation scenario, the sound source deployed in shallow water belongs to the first layer of sound velocity, with an emission angle of [missing information]. Due to the effect of the deep-sea acoustic channel, the sound waves are in the first... If a layer bends upwards, then the horizontal distance it travels through each layer to complete one bend is... :

[0069]

[0070] In the formula, Indicates the vocal timbre at the 1st position. The horizontal distance traversed by the layer; For the first Layer sound velocity gradient; Indicates the emission angle of the first layer as The corresponding feature parameters; Indicates the first The speed of sound in the layer; Indicates the number of layers in which the vocal timbre bends upwards.

[0071] in, For a given ray, i.e. with an exit angle The characteristic parameter of the sound ray is equal to the sound speed of the sound ray at the bending depth.

[0072] ;

[0073] in ( ) is the first Layer sound speed The angle of departure.

[0074] For the first Layer sound velocity gradient:

[0075] ;

[0076] Let the angle of emission of the other sound ray be the same as... Neighboring, for , The horizontal distance it travels through each layer when completing a bend is It can be known that The same applies to the previous formula. The expression of the pair Perform a Taylor expansion:

[0077] ;

[0078] ;

[0079] In the formula, Indicates the emission angle of the first layer as It is the corresponding number The horizontal distance traversed by the layer Indicates the first The change in the horizontal distance traversed by the layer is a small change. The resulting horizontal distance adjustment; Indicates the glancing angle.

[0080] When satisfied At that time, the signal in the convergence zone shows a peak. Since the target sound source and the sonar listener are not at the same depth, assuming the sonar listener is located at the [missing information] depth... Layer, and with the first The distance from the upper boundary of the layer is At that time, the distance of the gathering area :

[0081] ;

[0082] ;

[0083] In the formula, This refers to the horizontal propagation distance of a sonar receiver. It is the speed of sound at the depth where the sonar receiver is located.

[0084] (2) Width of the convergence zone

[0085] The convergence zone width is also determined by considering the first convergence zone in a fixed scenario, taking into account the incident angle of the target sound source. When the incident angle... When the value is 0, the sound rays are incident perpendicularly, with a relatively small curvature, allowing them to propagate and focus more effectively along the vocal tract. The reversal point of the sound rays in the convergence zone is farther away. According to the previous equation:

[0086] ;

[0087] in, , This represents the average sound velocity gradient along the vocal tract axis. The velocity of sound along the axial direction of the vocal tract; The speed of sound at the first level, starting from sea level; Maximum convergence zone distance; Minimum convergence zone distance.

[0088] When the incident angle of the target sound source reaches its maximum At this time, the propagation path of the sound rays is closer to horizontal, resulting in a weakened focusing effect and a closer reversal point in the convergence zone. Therefore:

[0089] ;

[0090] In the formula, This is the maximum angle of incidence.

[0091] According to the above formula, the width of the convergence region is defined as:

[0092] .

[0093] (3) Convergence region gain

[0094] One of the most important concerns when estimating target range under the convergence effect is the magnitude of the convergence gain in the underwater acoustic channel. Convergence gain refers to the increment in the acoustic intensity level calculated based on spherical spread and absorption loss when the peak acoustic intensity exceeds the peak intensity in the convergence region. According to classical ray theory, the acoustic intensity of a point source in a layered medium... Represented as:

[0095] ;

[0096] in, The sound intensity per unit distance; The sweep angle of the sonar receiver's sound rays; The first layer of sound velocity emission angle; This indicates the horizontal distance from the sound source to the sonar receiver. However, on the caustic line... Ray theory cannot calculate the sound field intensity of caustics and their neighborhoods. Under this condition, the convergence gain can be solved using wave theory.

[0097] Deep-sea acoustic velocity profile correlation function The parabolic form is:

[0098] ;

[0099] in, For parabola parameters, For depth, Let be the sound velocity along the vocal tract axis. For this type of sound velocity distribution, the eigenfunctions satisfy:

[0100] ;

[0101] ;

[0102] ;

[0103] In the formula, These represent eigenfunctions, used to describe the characteristics of the sound field distribution; These are the eigenvalues ​​of the sound field, which are related to the propagation path; It is the potential energy function, representing the influence of the sound speed gradient distribution; ω is the angular frequency of the sound wave; depth The speed of sound at a given location describes the distribution of the sound speed profile. Indicates the reference wavenumber; This represents the modal wavenumber.

[0104] at this time, The characteristic solution is the Hermitian function Format:

[0105] ;

[0106] In the formula, These are Hermitian polynomials used to describe the mode distribution of the sound field; This represents the scale parameter of the Hermitian function.

[0107] The convergence gain expression, considering the effective terms that restrict in-phase superposition, is finally obtained as follows:

[0108] ;

[0109] in, For convergence function, The assembly zone number, For the convergence zone interval, It is the reference wavenumber. and These represent the depths of the target sound source and the sonar listener, respectively.

[0110] Step S3, Bellhop sound field modeling: Input the convergence zone characteristic parameters and simulation parameters into the Bellhop sound field modeling tool to obtain simulated sound intensity data including propagation path and propagation loss.

[0111] Specifically, in this embodiment of the invention, a Bellhop sound field model is established within the selected sea area of ​​the underwater target distance estimation simulation scenario. This model is based on the ray tracing method, which decomposes the sound wave into many straight line segments. By calculating the path length, propagation loss, scattering and reflection, and other physical characteristics of each ray segment, the propagation path and propagation loss of the sound wave in the entire water area are finally calculated.

[0112] First, the environment file data is input into Bellhop, and some of the data read is shown in Table 1.

[0113] Table 1

[0114]

[0115] Secondly, a sound velocity profile is plotted using the average sound velocity, such as... Figure 5 As shown, the deep-sea acoustic duct axis is located at 1000m, the sound speed at the acoustic duct axis is about 1470m / s, and the critical depth is about 2500m.

[0116] Furthermore, the simulated scene sound field, sound rays, and propagation loss obtained using the Bellhop toolbox are as follows: Figure 6As shown, when the target sound source is at a depth of 150m and the sound ray incident angle is -15° to 15°, convergence zones appear at distances of 40–60km and 80–10km from the target sound source, while a sound shadow zone appears at 60–80km. The sonar listener, deployed at a distance of 45–55km from the target sound source and at a depth of 150m, is located in the first convergence zone, and the received sound signals are primarily the intrinsic rays of the target sound source.

[0117] Based on the sound field model and the calculation method for the convergence zone characteristics, the characteristic parameters of the deep-sea convergence zone are shown in Table 2. It can be seen that the first convergence zone is 45–46 km from the target sound source, with a width of 14–17 km, and a gain exceeding 15 dB. The calculation results are basically consistent with the sound field model, and under these conditions, it can effectively support the sonar receiver in detecting and locating the target sound source signal.

[0118] Table 2

[0119]

[0120] Step S4, target matching field localization modeling: compare the simulated sound intensity data with the measured sound intensity data of the sonar listener, and construct the cost function.

[0121] By calculating the acoustic intensity signal parameters of the converging region and comparing them with the acoustic intensity signal parameters actually received by the sonar listener, the target sound source can be located.

[0122] Each signal received by a sonar receiver consists of multiple sound rays. Locating a target sound source using sound intensity only requires extracting the sound intensity parameter from each signal ray. In the aforementioned analysis of the characteristic parameters of the deep-sea convergence zone, the sound intensity determined using the ray method is... It is related to the distance to the target.

[0123] When the sound intensity measurement value of the sonar listener A cost function is constructed using the correlation coefficient between the cost function and the sound intensity of the sound field model. :

[0124] ;

[0125] in, The number of sound ray intensities selected within the convergence zone. This is the lower limit of the convergence zone distance. This represents the upper limit of the distance to the convergence zone. Let cost function be The sound intensity.

[0126] Step S5, target distance estimation: By maximizing the cost function, the estimated horizontal distance between the target sound source and the sonar receiver is obtained, thereby completing the underwater target localization.

[0127] Specifically, according to the cost function, when the estimated target sound source distance is equal to the actual target sound source distance, the sound intensity in the convergence zone of the sound field model perfectly matches the actual convergence zone sound intensity. At this point, the correlation coefficient will reach its maximum value, theoretically 1. That is, the problem of calculating the target sound source distance is transformed into solving for the maximum value of the cost function. Question:

[0128] ;

[0129] Then, the location can be determined based on the distance corresponding to the extreme value.

[0130] The method described in this invention establishes a Bellhop sound field model to obtain the target sound intensity received by a sonar listener within the convergence zone, and matches it with the actual sound intensity, thereby achieving the localization of sound sources in deep-sea convergence zones and providing a solution to the problem of locating deep-sea targets. Simulation verification results are provided. Figure 7 and Figure 8 As shown, the specific effects are as follows: When the sound source is located at different depths, namely 150m, 180m, and 200m, the target at a depth of 200m achieves the largest convergence gain and the smallest positioning error, with an error of approximately 1.78%. The results compared to traditional matched-field processing are as follows... Figure 9 As shown.

[0131] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; only preferred embodiments of the present invention are illustrated. The descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. As long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0132] It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept, and these all fall within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A method for underwater target matching field localization that integrates convergence zone acoustic intensity gain, characterized in that: Includes the following steps: Step S1, Simulation Scenario Configuration: Set the deployment parameters of underwater sound sources in the target sea area, including sound source depth, emission angle range and frequency, and deploy sonar listeners in the first convergence zone to generate simulation parameters; Step S2, Deep-sea convergence zone characteristic analysis: Based on the simulation parameters and sea area sound velocity profile data, using layered sound velocity modeling and sound ray propagation model, the distance, width and convergence zone gain of the first convergence zone formed by the target sound source are calculated to obtain the convergence zone characteristic parameters; Step S3, Bellhop sound field modeling: Input the convergence zone characteristic parameters and the simulation parameters into the Bellhop sound field modeling tool to obtain simulated sound intensity data including propagation path and propagation loss; Step S4, target matching field localization modeling: compare the simulated sound intensity data with the measured sound intensity data of the sonar listener, and construct a cost function; Step S5, target distance estimation: By maximizing the cost function, the estimated horizontal distance between the target sound source and the sonar listener is obtained, thereby completing the underwater target localization.

2. The underwater target matching field localization method according to claim 1, characterized in that: The distance of the first convergence zone is calculated based on the relationship between the sound ray exit angle and the interlayer sound velocity gradient; the width of the first convergence zone is calculated by the difference in the horizontal distance of the sound ray at the maximum and minimum incident angles; the gain of the first convergence zone is derived based on the sound field eigenfunctions and Hermitian functions in wave theory.

3. The underwater target matching field localization method according to claim 2, characterized in that: In step S2, the method for calculating the distance of the first convergence region includes: Step S211: Based on the sound speed gradient, divide the water body from the sea surface to the seabed into several layers; Step S212: Calculate the horizontal distance traveled by the sound ray in each layer during the first bend. Its expression is: ； In the formula, Indicates the vocal timbre at the 1st The horizontal distance traversed by the layer; For the first Layer sound velocity gradient; The first layer's emission angle is... The corresponding feature parameters; Indicates the first The speed of sound in the layer; Indicates the number of upward bends in the vocal timbre; Step S213: Let the emission angle of the other sound ray be... , Its corresponding horizontal distance Using the first sound ray as a reference, a Taylor expansion of the horizontal distance with respect to the angle is performed to obtain the change in horizontal distance. The expression is: ； In the formula, The first layer's emission angle is... It is the corresponding number The horizontal distance traversed by the layer Indicates the first The change in the horizontal distance traversed by the layer; Indicates the glancing angle; Step S214: When At that time, the sonar listener was set to the position of the first... Layer, and with the first The distance from the upper boundary of the layer is Calculate the distance to the convergence zone for: ； ； In the formula, It is the voice from the first The upper boundary of the layer propagates to the horizontal distance of the sonar listener; It is the speed of sound at the depth where the sonar listening device is located.

4. The underwater target matching field localization method according to claim 3, characterized in that: In step S2, the method for calculating the width of the first convergence region includes: Step S221: Set the incident angle to 0 and calculate the maximum convergence zone distance. : ； In the formula, and These represent the average sound velocity gradients along and below the vocal tract axis; The velocity of sound along the axial direction of the vocal tract; The speed of sound at the first level, starting from sea level; Step S222: Set the angle of incidence as the maximum angle of incidence. Calculate the minimum convergence distance : ； Step S223: Subtract the minimum convergence distance from the maximum convergence distance to obtain the width of the first convergence region.

5. The underwater target matching field localization method according to claim 4, characterized in that: The convergence region gain mentioned in step S2 The expression is: ； In the formula, The assembly zone number; Intervals between convergence zones; Indicates wave number; Represents the convergence function; and The depths of the underwater sound source and the sonar receiver are respectively. These are the parameters of the parabola.

6. The underwater target matching field localization method according to claim 1, characterized in that: The cost function described in step S4 The expression is: ； In the formula, The number of sound ray intensities selected within the convergence zone; This represents the lower limit of the convergence zone distance; This represents the upper limit of the convergence zone distance; Sound intensity; The sound intensity measurement value of the sonar listener; This indicates the horizontal distance between the candidate target sound source and the listener.

7. An underwater target matching field localization system that integrates convergence zone acoustic intensity gain, applicable to the method described in any one of claims 1 to 6, characterized in that: include: The simulation configuration module is used to set the deployment parameters of underwater sound sources in the target sea area, including the depth, emission angle range and frequency of the sound sources, and to configure the deployment parameters of the sonar listener at the first convergence zone position to generate simulation parameters. The convergence zone analysis module is used to calculate the distance, width and convergence zone gain of the first convergence zone formed by the sound source based on the simulation parameters and the sea area sound velocity profile data, using a layered sound velocity model and a sound ray propagation model, and to obtain the convergence zone characteristic parameters. The sound field modeling module is used to input the convergence zone characteristic parameters and the simulation parameters into the Bellhop sound field modeling tool, simulate the sound wave propagation path based on the ray tracing method, and obtain simulated sound intensity data including the propagation path and propagation loss. The data acquisition module is used to acquire measured sound intensity data collected by sonar listeners deployed in the first convergence zone; The positioning processing module is used to compare the simulated sound intensity data with the measured sound intensity data, construct a cost function, and estimate the horizontal distance between the target sound source and the sonar listener by solving for the maximum value of the cost function, thereby realizing the matching field positioning of the underwater target.

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