Broadband sound source depth estimation method matched with deep sea sound velocity profile
By using a layered medium model and broadband beamforming processing, a correspondence between the interference period and the sound source depth was established, solving the accuracy problem of deep-sea target depth estimation at long distances and in complex environments, and achieving accurate estimation of the sound source depth.
Patent Information
- Application Number
- CN202511433479.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-09
- Publication Date
- 2026-01-13
AI Technical Summary
Existing methods for estimating the depth of deep-sea underwater targets are not accurate enough under low signal-to-noise ratio conditions, and are affected by sound velocity profile mismatch and environmental noise, making it difficult to achieve accurate depth estimation at long distances.
By employing a layered medium model and performing broadband beamforming processing on the received sound field of a vertical linear array, a frequency-vertical angle of arrival spectrum is obtained. Utilizing the correspondence between the interference period and the sound source depth, this spectrum is mapped to the grazing angle-depth domain, forming an ambiguity plane for the sound source depth, thus enabling depth estimation of underwater broadband sound sources.
It achieves accurate and rapid estimation of sound source depth in long-distance and complex environments, overcomes the limitations of the isovelocity approximation method, and has good environmental adaptability.
Smart Images
Figure CN121325149A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of this application relate to the field of underwater acoustic detection technology, and in particular to a broadband sound source depth estimation method that matches deep-sea sound velocity profiles. Background Technology
[0002] Depth information, as one of the key criteria for distinguishing between surface and underwater targets, is of great significance for target detection, localization, and identification. In the deep-sea environment, due to the low ambient noise and good propagation characteristics of the direct acoustic zone, sensors (sensor arrays) deployed at great depths can receive high signal-to-noise ratio radiated noise from near-surface targets, thus enabling passive detection of a wide range of underwater acoustic targets.
[0003] In recent years, numerous passive estimation methods for the depth of deep-sea underwater targets have been proposed. These methods can be broadly categorized into three types: methods based on matched field processing, methods based on multipath arrival structures, and methods based on interferometric features. Among these, matched field processing, as a typical model-based processing technique, was applied early in deep-sea sound source localization and has undergone sea trials. However, this method is significantly affected by environmental mismatch and typically requires large-scale sensor arrays to improve positioning accuracy, which limits its engineering applications in deep-sea underwater target depth estimation. Methods based on deep-sea multipath arrival structures and methods based on acoustic field interferometric features are essentially the same; both utilize the periodic variation of the receiver's acoustic field intensity caused by the coherent superposition of direct waves and sea surface reflected waves (Lloyd's mirror interference effect) to estimate the target depth. Among these methods, the multipath arrival structure (MIS) approach extracts the multipath angle of arrival (MIA) and multipath delay difference from the received signal and combines this with the geometric positional relationship between the target and the receiver to calculate the distance and depth of an underwater target. However, under low signal-to-noise ratio (SNR) conditions, the MIS is not readily apparent, and estimating the delay difference typically requires longer integration time and wider processing bandwidth, placing higher demands on the processing power and sampling rate of the receiving system. Furthermore, after Fourier transform, the MIS at different distances can yield a range-frequency interference structure. Utilizing the periodic oscillation characteristics of this range-frequency interference structure, the depth of the target sound source can be estimated.
[0004] Most methods utilizing deep-sea acoustic field interference structures are based on the idea of matched beam intensity processing, and usually approximate the deep-sea acoustic velocity profile as an isosceles model. However, the actual deep-sea environment is very complex. Therefore, environmental mismatch and the accuracy of the acoustic field model itself become the main factors limiting its application to practical engineering. Summary of the Invention
[0005] To address the aforementioned technical problems, embodiments of this application propose a broadband sound source depth estimation method that matches deep-sea sound velocity profiles. The method aims to derive the correspondence between broadband sound source depth and interference period using a layered medium model, mapping the frequency-angle of arrival spectrum to a depth ambiguity plane. This enables accurate and rapid depth estimation of underwater broadband sound sources at greater distances and exhibits good environmental adaptability.
[0006] To achieve the above objectives, embodiments of this application propose a broadband sound source depth estimation method matching deep-sea sound velocity profiles. The method includes: for a fixed underwater broadband sound source, obtaining a frequency-vertical angle of arrival spectrum by performing broadband beamforming processing on the received sound field of a vertical linear array; using a layered medium model, analyzing the characteristics of the interference period of the frequency-vertical angle of arrival spectrum to establish a correspondence between the interference period and the sound source depth; based on the correspondence between the interference period and the sound source depth, mapping the frequency-vertical angle of arrival spectrum to the grazing angle-depth domain to form an ambiguity plane for the sound source depth; and based on the ambiguity plane, realizing the depth estimation of the underwater broadband sound source.
[0007] To achieve the above objectives, embodiments of this application also propose a broadband sound source depth estimation system matching deep-sea sound velocity profiles. The system includes: a broadband beamforming unit for obtaining a frequency-vertical angle of arrival (VOA) spectrum from a fixed underwater broadband sound source by performing broadband beamforming on the received sound field of a vertical linear array; a feature analysis unit for analyzing the characteristics of the interference period of the VOA spectrum using a layered medium model to establish a correspondence between the interference period and the sound source depth; a mapping unit for mapping the VOA spectrum to a grazing angle-depth domain based on the correspondence between the interference period and the sound source depth, forming an ambiguity plane for the sound source depth; and an execution unit for estimating the depth of the underwater broadband sound source based on the ambiguity plane.
[0008] To achieve the above objectives, embodiments of this application also propose an electronic device, including: a processor and a memory, wherein the memory stores instructions executable by the processor, and the processor is configured to execute the instructions such that the electronic device can implement a broadband sound source depth estimation method matching deep-sea sound velocity profiles as described above.
[0009] To achieve the above objectives, embodiments of this application also propose a computer-readable storage medium storing a computer program that, when executed by a processor, enables a broadband sound source depth estimation method matching deep-sea sound velocity profiles as described above.
[0010] This application proposes a broadband sound source depth estimation method based on matching deep-sea sound velocity profiles. For a fixed underwater broadband sound source, the method first obtains the frequency-vertical angle of arrival (VOA) spectrum by performing broadband beamforming on the received sound field of a vertical linear array. Then, using a layered medium model, the characteristics of the interference period of the VOA spectrum are analyzed to establish a correspondence between the interference period and the sound source depth. Next, based on this correspondence, the VOA spectrum is mapped to the grazing angle-depth domain, forming an ambiguity plane for the sound source depth. Finally, the depth of the underwater broadband sound source can be estimated based on this ambiguity plane. This method effectively overcomes the limitations of the isovelocity approximation method and effectively overcomes the depth estimation error caused by the mismatch of the actual sound velocity profile at long distances. It can still achieve accurate and rapid sound source depth estimation at considerable distances and has good environmental adaptability.
[0011] Alternatively, under the far-field plane wave assumption, for The response vector of the incoming wave signal in the direction of the vertical linear array is expressed by formula (1): (1); in, For the sound field frequency, For the number of array elements, For the spacing between array elements, The speed of sound of seawater, This represents the response vector of a vertical linear array, i.e., the received sound field of the vertical linear array, indicated by the superscript. This indicates taking the transpose.
[0012] Optionally, by performing broadband beamforming processing on the received sound field of the vertical linear array, the obtained frequency-vertical angle of arrival spectrum is expressed by formula (2): (2); in, for The sampling covariance matrix at a given frequency point, with the upper right subscript... This indicates taking the inverse of the matrix, with the upper right subscript... This indicates taking the conjugate transpose. The frequency-vertical angle of arrival spectrum is also denoted as... .
[0013] Alternatively, for a fixed underwater broadband sound source, the frequency-vertical angle of arrival spectrum will produce a frequency interference fringe with alternating bright and dark edges, the interference period of which depends on the depth of the underwater broadband sound source. lie in The underwater broadband sound source at a depth of The sound field at the receiving hydrophone This can be expressed by formula (3): (3); in, This represents the peak value of the complex spectrum of an underwater broadband sound source. For surface reflectance, Indicates the direct wave path The tilt distance, Indicates the surface reflection path The tilt distance, Indicates the depth of an underwater broadband sound source. This indicates the distance between the underwater broadband sound source and the vertical linear array; Based on formula (3), considering only the phase difference, It can be approximated by formula (4): (4); in, , express Path and Time difference of arrival between paths Indicates the angle of arrival at vertical distance; According to formula (4), the location is... The underwater broadband sound source at a depth of Sound intensity at the receiving hydrophone , This can be expressed by formula (5): (5); in, .
[0014] Optionally, to match the characteristics of deep-sea sound velocity profiles, the stratified medium properties of seawater are considered. wave and The arrival time delay of the wave is approximately expressed by formula (6): (6); in, Indicates depth as At the angle, Indicates depth as Speed of sound in the seawater at that location; According to Snell's Law, formula (6) can be rewritten as formula (7): (7); in, The center depth of the vertical linear array.
[0015] Alternatively, in the far-field approximation, wave and The waves are considered as two plane waves arriving at the same angle with a fixed time delay; based on formulas (5) and (7), the beamforming output of the vertical linear array at the angle of arrival of the underwater broadband sound source is obtained. , This can be expressed by formula (8): (8); The relationship between the interference period and the sound source depth is expressed by formula (9): (9); in, The interference period.
[0016] Optionally, based on the correspondence between the interference period and the sound source depth, the frequency-vertical angle of arrival spectrum is mapped to the grazing angle-depth domain to form an ambiguity plane for the sound source depth, including: based on ,Will Mapped to the grazing angle-depth domain, this forms an ambiguity plane for the sound source depth. , This can be expressed by formula (10): (10); in, and These are the upper and lower limits of the processing frequency band, respectively. The maximum value corresponds to the depth estimation result of the underwater broadband sound source. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies of this application will be briefly introduced below. Obviously, the following drawings are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings described herein are only used to explain this application and are not intended to limit this application.
[0018] Figure 1 This is a flowchart of a broadband sound source depth estimation method for matching deep-sea sound velocity profiles provided in one embodiment of this application; Figure 2 This is a detailed schematic diagram of a broadband sound source depth estimation method that matches deep-sea sound velocity profiles provided in one embodiment of this application; Figure 3 This is a schematic diagram of a deep-sea sound velocity profile provided in one embodiment of this application; Figure 4This is a schematic diagram of Lloyd's mirror acoustic field interference and a schematic diagram of MVDR broadband beam output power provided in one embodiment of this application; Figure 5 This is a comparison diagram of the depth estimation results of a sound source based on the isovelocity approximation method and the present method, provided in one embodiment of this application. Figure 6 This is a comparison diagram of the depth estimation results of sound sources at different depths provided in one embodiment of this application, based on the method of isotropic approximation and the method of this application. Figure 7 This is a comparison diagram of the depth estimation results of sound sources at different horizontal distances provided in one embodiment of this application, based on the isovelocity approximation method and the present method. Figure 8 This is a comparison diagram of the depth separation results of multiple sound sources provided in one embodiment of this application, based on the isovelocity approximation method and the present method. Figure 9 This is a schematic diagram of the structure of a broadband sound source depth estimation system that matches deep-sea sound velocity profiles, provided in another embodiment of this application; Figure 10 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. Those skilled in the art will understand that many technical details have been presented in the embodiments of this application to facilitate better understanding. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this application. The following embodiments can be combined with and referenced by each other without contradiction.
[0020] To address the performance degradation of traditional deep-sea sound source depth estimation methods due to factors such as sound velocity profiles, environmental noise, and strong interference, one embodiment of this application proposes a broadband sound source depth estimation method that matches deep-sea sound velocity profiles. This method is applied to electronic devices, which can be terminals or servers. This embodiment and subsequent embodiments will use a server as an example for illustration. The implementation details of the broadband sound source depth estimation method that matches deep-sea sound velocity profiles proposed in this embodiment are described below. These details are provided for ease of understanding and are not essential for implementing this solution.
[0021] The specific process of the broadband sound source depth estimation method matching deep-sea sound velocity profiles proposed in this embodiment can be described as follows: Figure 1 As shown, its visual details can be as follows Figure 2 As shown, the method includes: Step 11: For a fixed underwater broadband sound source, the frequency-vertical angle of arrival spectrum is obtained by performing broadband beamforming processing on the received sound field of the vertical linear array.
[0022] In a specific implementation, for a fixed underwater broadband sound source, this embodiment obtains the frequency-vertical angle of arrival spectrum (also known as the frequency-grazing angle spectrum) by performing broadband beamforming processing on the received sound field of the vertical linear array.
[0023] Under the assumption of far-field plane waves, for The response vector (also known as the scan vector) of the vertical linear array of incoming wave signals is expressed by formula (1): (1); in, For the sound field frequency, For the number of array elements, For the spacing between array elements, The speed of sound of seawater, This represents the response vector of a vertical linear array, i.e., the received sound field of the vertical linear array, indicated by the superscript. This indicates taking the transpose.
[0024] Response vector for vertical linear array By performing broadband beamforming on the received sound field of the vertical linear array, the frequency-vertical angle of arrival spectrum can be obtained, which is expressed by formula (2): (2); in, for The sampling covariance matrix at a given frequency point, with the upper right subscript... This indicates taking the inverse of the matrix, with the upper right subscript... This indicates taking the conjugate transpose. The frequency-vertical angle of arrival spectrum is also denoted as... .
[0025] Step 12: Using the layered medium model, analyze the characteristics of the interference period of the frequency-vertical angle of arrival spectrum and establish the correspondence between the interference period and the sound source depth.
[0026] In practical implementation, after obtaining the frequency-vertical angle of arrival spectrum, it is necessary to use the layered medium model to analyze the characteristics of the interference period of the frequency-vertical angle of arrival spectrum, thereby establishing the correspondence between the interference period and the sound source depth.
[0027] For a fixed underwater broadband sound source, the frequency-vertical angle of arrival spectrum will produce a frequency interference fringe with alternating bright and dark areas. The period of this alternation (interference period) depends on the depth of the underwater sound source.
[0028] lie in The underwater broadband sound source at a depth of The sound field at the receiving hydrophone This can be expressed by formula (3): (3); in, This represents the peak value of the complex spectrum of an underwater broadband sound source. For surface reflectance, Indicates the direct wave path The tilt distance, Indicates the surface reflection path The tilt distance.
[0029] Based on formula (3), considering only the phase difference, It can be approximated by formula (4): (4); in, , express Path and Time difference of arrival between paths Indicates the vertical angle of arrival.
[0030] According to formula (4), the location is... The underwater broadband sound source at a depth of Sound intensity at the receiving hydrophone , This can be expressed by formula (5): (5); in, .
[0031] As can be seen from formulas (4) and (5), the frequency domain interference structure of the sound field of the direct sound and the first reflection sound from the sea surface is related to the sound source depth, frequency, and target pitch angle, and its envelope exhibits periodic changes.
[0032] To match the characteristics of deep-sea sound velocity profiles, the stratified medium properties of seawater are considered. wave and The arrival time delay of the wave is approximately expressed by formula (6): (6); in, Indicates depth as At the angle, Indicates depth as The speed of sound of the seawater at that location.
[0033] According to Snell's Law, formula (6) can be rewritten as formula (7): (7); in, The center depth of the vertical linear array.
[0034] Under the far-field approximation wave and The waves are considered as two plane waves arriving at the same angle with a fixed time delay. Based on formulas (5) and (7), the beamforming output of the vertical linear array at the angle of arrival of the underwater broadband sound source is obtained. , This can be expressed by formula (8): (8).
[0035] The relationship between the interference period and the sound source depth is expressed by formula (9): (9); in, The interference period.
[0036] Step 13: Based on the correspondence between the interference period and the sound source depth, the frequency-vertical angle of arrival spectrum is mapped to the grazing angle-depth domain to form an ambiguity plane for the sound source depth.
[0037] Step 14: Based on the ambiguity plane, depth estimation of the underwater broadband sound source is achieved.
[0038] In practical implementation, after establishing the correspondence between the interference period and the sound source depth, the frequency-vertical angle of arrival spectrum can be mapped to the grazing angle-depth domain based on the correspondence between the interference period and the sound source depth, thereby forming an ambiguity plane of the sound source depth, and the depth estimation of the underwater broadband sound source can be realized based on the ambiguity plane.
[0039] In obtaining Next, this embodiment will Mapped to the grazing angle-depth domain, this forms an ambiguity plane for the sound source depth. , This can be expressed by formula (10): (10); in, and These are the upper and lower limits of the processing frequency band, respectively. The maximum value corresponds to the depth estimation result of the underwater broadband sound source.
[0040] This embodiment proposes a broadband sound source depth estimation method that matches deep-sea sound velocity profiles. For a fixed underwater broadband sound source, the method first obtains the frequency-vertical angle of arrival (VOA) spectrum by performing broadband beamforming on the received sound field of a vertical linear array. Then, using a layered medium model, the characteristics of the interference period of the VOA spectrum are analyzed to establish a correspondence between the interference period and the sound source depth. Next, based on this correspondence, the VOA spectrum is mapped to the grazing angle-depth domain, forming an ambiguity plane for the sound source depth. Finally, the depth of the underwater broadband sound source can be estimated based on this ambiguity plane. This method effectively overcomes the limitations of the isovelocity approximation method and effectively overcomes the depth estimation error caused by the mismatch of the actual sound velocity profile at long distances. It can still achieve accurate and rapid sound source depth estimation at long distances and has good environmental adaptability.
[0041] The steps described above are for clarity only. In implementation, they can be combined into one step, or some steps can be broken down into multiple steps, as long as they involve the same logical relationship, they are all within the scope of protection of this application. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, without changing the core design of the algorithm and process, are also within the scope of protection of this application.
[0042] In one embodiment, to verify the effectiveness of the broadband sound source depth estimation method (hereinafter referred to as "the method") proposed in this application that matches the deep-sea sound velocity profile, we conducted relevant simulation experiments.
[0043] The simulation environment is a typical deep-sea area of the South China Sea, with local depths reaching 4000m. The seabed topography is flat and horizontally isotropic, and its sound velocity profile can be obtained as follows: Figure 3 As shown, the acoustic channel axis depth is approximately 1250m, which is typical of a non-fully deep-sea acoustic channel. The receiver is a deep-sea bottom-mounted 32-element vertical linear array (element spacing is 4m, array center depth is 3870m). The underwater sound source radiated noise level is 112.3dB@300Hz, and the frequency range of the radiated signal is 100Hz to 200Hz. Furthermore, the sound field was calculated using the Bellhop ray tracing model.
[0044] The specific implementation process of the deep-sea sound source depth estimation method is as follows.
[0045] 1) Broadband MVDR beamforming.
[0046] In the above simulation environment, such as Figure 4 As shown, the depth of the underwater broadband sound source is assumed to be... The distance between the receiving vertical line array According to formula (2), the received sound field of the vertical linear array is processed by broadband beamforming to obtain the frequency-vertical angle of arrival spectrum. .
[0047] 2) Depth mapping of frequency-vertical angle of arrival spectrum to match deep-sea sound velocity profile characteristics.
[0048] like Figure 4 As shown, the emitted sound waves from the underwater broadband sound source pass through direct wave paths ( Path) and the path of first reflection from the sea surface ( The two acoustic signals arrive at the receiving array via a path. After coherent superposition, alternating bright and dark frequency interference fringes are formed in the broadband beam output diagram of the array. The alternation period of the bright and dark fringes implies the depth information of the underwater broadband sound source.
[0049] The relationship between the interference period and the sound source depth can be established according to formula (9).
[0050] 3) Formation of the ambiguity plane and realization of depth estimation.
[0051] Will Mapping to the grazing angle-depth domain yields an ambiguity plane for the sound source depth of the underwater broadband sound source. , The maximum value corresponds to the depth estimation result of the underwater broadband sound source.
[0052] Figure 5 The figures show the source depth ambiguity planes obtained by the method based on the isovelocity approximation and by the method presented herein, respectively. The source depth is 200m, the distance is 17km, and the signal-to-noise ratio (SNR) is -16.1dB. Figure 5 As can be seen, due to the presence of environmental noise, the peak position in the ambiguity plane of the method based on the constant sound velocity approximation appears at 179m, while the peak position in the ambiguity plane of this method appears at 205m. This method can obtain more accurate sound source depth estimation results.
[0053] In addition, we conducted a comparative analysis of the performance of the isovelocity approximation method and our proposed method under different sound source depths and horizontal distances. Figure 6 The results for constant-depth analysis using the method based on the constant sound velocity approximation and the proposed method are presented at different sound source depths (100m and 200m), with SNR values of -15.5dB and 16.5dB, respectively. Figure 6As can be seen, the sound source position in the depth ambiguity plane obtained using the method based on the constant sound velocity approximation deviates from the true sound source depth. The ambiguity plane obtained by this method shows significant bright spots near the true sound source position, enabling accurate estimation of the sound source depth. Figure 7 The results for different sound source distances (17km and 23km) are presented, using the method based on the isovelocity approximation and the method described in this paper, with SNR values of -16.1dB and -17.5dB, respectively. Figure 7 As can be seen, the method based on the constant sound velocity approximation has an increased error in estimating the depth of a sound source at different horizontal distances as the distance increases, while our method can still provide relatively accurate depth estimation results.
[0054] To verify the depth estimation and resolution capabilities of this method in multi-sound-source scenarios, three underwater sound sources at different locations were considered. , and The horizontal distances are 12 km, 17 km and 22 km respectively, and the depths are 50 m, 100 m and 200 m respectively. Figure 8 The depth estimation results for multiple sound sources are presented respectively using the method based on the isovelocity approximation and the proposed method. Figure 8 It can be seen from this that, due to and Due to the considerable distance, the depth estimation results obtained using the isovelocity approximation method yield larger errors. In contrast, this method not only achieves effective separation of the depths of each sound source but also maintains high depth estimation accuracy (for...). , and depth estimation error rate The percentages were 4.0%, 6.0%, and 2.5% respectively, which demonstrates the effectiveness of this method in complex multi-source environments.
[0055] This method can be applied to broadband sound source depth estimation in complex deep-sea environments. Addressing the issues of methods based on the isovelocity approximation being susceptible to environmental noise and exhibiting large estimation errors at long distances, this method effectively improves the accuracy of sound source depth estimation and demonstrates good environmental adaptability.
[0056] Accordingly, another embodiment of this application proposes a broadband sound source depth estimation system that matches the deep-sea sound velocity profile. The details of the broadband sound source depth estimation system that matches the deep-sea sound velocity profile proposed in this embodiment are described in detail below. The following implementation details are provided for ease of understanding only and are not necessary for implementing this solution. Figure 9This is a schematic diagram of the structure of a broadband sound source depth estimation system that matches the deep-sea sound velocity profile proposed in this embodiment, including: a broadband beamforming unit 21, a feature analysis unit 22, a mapping unit 23, and an execution unit 24.
[0057] The broadband beamforming unit 21 is used to obtain the frequency-vertical angle of arrival spectrum by performing broadband beamforming processing on the received sound field of the vertical linear array for a fixed underwater broadband sound source.
[0058] The feature analysis unit 22 is used to analyze the characteristics of the interference period of the frequency-vertical angle of arrival spectrum using a layered medium model, and to establish the correspondence between the interference period and the sound source depth.
[0059] The mapping unit 23 is used to map the frequency-vertical arrival angle spectrum to the grazing angle-depth domain based on the correspondence between the interference period and the sound source depth, forming an ambiguity plane for the sound source depth.
[0060] Execution unit 24 is used to perform depth estimation of underwater broadband sound sources based on the ambiguity plane.
[0061] It is not difficult to see that this embodiment is a system embodiment corresponding to the above method embodiments, and this embodiment can be implemented in conjunction with the above method embodiments. The relevant technical details and technical effects mentioned in the above method embodiments are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the above method embodiments.
[0062] It is worth mentioning that all modules and units involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed in this application; however, this does not mean that other units do not exist in this embodiment.
[0063] Another embodiment of this application provides an electronic device, such as Figure 10 As shown, it includes a processor 31 and a memory 32. The memory 32 stores instructions that the processor 31 can execute. When the processor 31 is configured to execute the instructions, the electronic device can implement a broadband sound source depth estimation method matching deep-sea sound velocity profile as described in the above method embodiment.
[0064] The memory and processor are connected via a bus, which includes any number of interconnecting buses and bridges, connecting various circuits of one or more processors and the memory. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single component or multiple components, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.
[0065] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.
[0066] Another embodiment of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, can implement a broadband sound source depth estimation method matching deep-sea sound velocity profiles as described in the above method embodiments.
[0067] That is, those skilled in the art will understand that all or part of the steps in the above method embodiments can be implemented by a program instructing related hardware. The program is stored in a storage medium and includes several instructions to cause a device (such as a microcontroller, chip, etc.) or processor to execute all or part of the steps of the method described in the method embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.
[0068] Those skilled in the art will understand that the above embodiments are specific implementations of this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.
Claims
1. A broadband sound source depth estimation method matching deep-sea sound velocity profiles, characterized in that, include: For a fixed underwater broadband sound source, the frequency-vertical angle of arrival spectrum is obtained by performing broadband beamforming processing on the received sound field of the vertical linear array. Using a layered medium model, the characteristics of the interference period of the frequency-vertical angle of arrival spectrum are analyzed, and the correspondence between the interference period and the sound source depth is established. Based on the correspondence between the interference period and the sound source depth, the frequency-vertical angle of arrival spectrum is mapped to the grazing angle-depth domain to form an ambiguity plane for the sound source depth. Depth estimation of underwater broadband sound sources is achieved based on the ambiguity plane.
2. The broadband sound source depth estimation method for matching deep-sea sound velocity profiles as described in claim 1, characterized in that, Under the assumption of far-field plane waves, for The response vector of the incoming wave signal in the direction of the vertical linear array is expressed by formula (1): （1）； in, For the sound field frequency, For the number of array elements, For the spacing between array elements, The speed of sound of seawater, This represents the response vector of a vertical linear array, i.e., the received sound field of the vertical linear array, indicated by the superscript. This indicates taking the transpose.
3. The broadband sound source depth estimation method for matching deep-sea sound velocity profiles as described in claim 2, characterized in that, By performing broadband beamforming on the received sound field of the vertical linear array, the resulting frequency-vertical angle of arrival spectrum is expressed by formula (2): （2）； in, for The sampling covariance matrix at a given frequency point, with the upper right subscript... This indicates taking the inverse of the matrix, with the upper right subscript... This indicates taking the conjugate transpose. The frequency-vertical angle of arrival spectrum is also denoted as... .
4. The broadband sound source depth estimation method for matching deep-sea sound velocity profiles as described in claim 3, characterized in that, For a fixed underwater broadband sound source, the frequency-vertical angle of arrival spectrum will produce a frequency interference fringe with alternating bright and dark edges, the period of which depends on the depth of the underwater broadband sound source. lie in The underwater broadband sound source at a depth of The sound field at the receiving hydrophone This can be expressed by formula (3): （3）； in, This represents the peak value of the complex spectrum of an underwater broadband sound source. For surface reflectance, Indicates the direct wave path The tilt distance, Indicates the surface reflection path The tilt distance, Indicates the depth of an underwater broadband sound source. This indicates the distance between the underwater broadband sound source and the vertical linear array; Based on formula (3), considering only the phase difference, It can be approximated by formula (4): （4）； in, , express Path and Time difference of arrival between paths Indicates the angle of arrival at vertical distance; According to formula (4), the location is... The underwater broadband sound source at a depth of Sound intensity at the receiving hydrophone , This can be expressed by formula (5): （5）； in, .
5. The broadband sound source depth estimation method for matching deep-sea sound velocity profiles as described in claim 4, characterized in that, To match the characteristics of deep-sea sound velocity profiles, the stratified medium properties of seawater are considered. wave and The arrival time delay of the wave is approximately expressed by formula (6): （6）； in, Indicates depth as At the angle, Indicates depth as Speed of sound in the seawater at that location; According to Snell's Law, formula (6) can be rewritten as formula (7): （7）； in, The center depth of the vertical linear array.
6. The broadband sound source depth estimation method for matching deep-sea sound velocity profiles as described in claim 5, characterized in that, Under the far-field approximation wave and The waves are considered as two plane waves arriving at the same angle with a fixed time delay. Based on formulas (5) and (7), the beamforming output of the vertical linear array at the angle of arrival of the underwater broadband sound source is obtained. , This can be expressed by formula (8): （8）； The relationship between the interference period and the sound source depth is expressed by formula (9): （9）； in, The interference period.
7. The broadband sound source depth estimation method for matching deep-sea sound velocity profiles as described in claim 6, characterized in that, Based on the correspondence between the interference period and the sound source depth, the frequency-vertical angle of arrival spectrum is mapped to the grazing angle-depth domain to form an ambiguity plane for the sound source depth, including: based on ,Will Mapped to the grazing angle-depth domain, this forms an ambiguity plane for the sound source depth. , This can be expressed by formula (10): （10）； in, and These are the upper and lower limits of the processing frequency band, respectively. The maximum value corresponds to the depth estimation result of the underwater broadband sound source.
8. A broadband sound source depth estimation system matching deep-sea sound velocity profiles, characterized in that, include: A broadband beamforming unit is used to obtain a frequency-vertical angle of arrival spectrum for a fixed underwater broadband sound source by performing broadband beamforming processing on the received sound field of a vertical linear array. The feature analysis unit is used to analyze the characteristics of the interference period of the frequency-vertical angle of arrival spectrum using a layered medium model, and to establish the correspondence between the interference period and the sound source depth. The mapping unit is used to map the frequency-vertical angle of arrival spectrum to the grazing angle-depth domain based on the correspondence between the interference period and the sound source depth, forming an ambiguity plane for the sound source depth. The execution unit is used to perform depth estimation of underwater broadband sound sources based on the ambiguity plane.
9. An electronic device, characterized in that, include: A processor and a memory, wherein the memory stores instructions that the processor can execute, and the processor is configured to, when executing the instructions, enable the electronic device to implement a broadband sound source depth estimation method matching a deep-sea sound velocity profile as described in any one of claims 1 to 7.
10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it can implement a broadband sound source depth estimation method that matches a deep-sea sound velocity profile as described in any one of claims 1 to 7.