A method for evaluating equivalent target strength of a target wake field induced sound field

Abstract

The application relates to the technical field of underwater acoustic detection, in particular to a method for evaluating equivalent target strength of a target wake-induced sound field, which comprises the following steps: establishing an underwater acoustic environment; calculating a receiving-end sound field before and after target intrusion in the underwater acoustic environment; calculating a receiving-end sound field anomaly component based on the receiving-end sound field before and after target intrusion; back-propagating the receiving-end sound field anomaly component to a position 1 m away from an internal wave equivalent sound center, so as to convert the target wake-induced sound field into an equivalent scattering sound field; calculating an incident sound field at the internal wave equivalent sound center based on a path superposition principle; constructing equivalent target strength of the target wake-induced sound field based on the equivalent scattering sound field and the incident sound field; and embedding the equivalent target strength of the target wake-induced sound field into a sonar equation to carry out detection efficiency evaluation. The method realizes statistical measurement of the acoustic effect of the target wake field and has strong engineering usability.

Description

Technical Field

[0001] The embodiments of this application relate to the field of underwater acoustic detection technology, and in particular to a method for evaluating the equivalent target intensity of a sound field induced by a target wake field. Background Technology

[0002] In the field of underwater acoustic detection technology, active sonar systems locate, identify, and track underwater targets by emitting sound waves and receiving the echo signals reflected or disturbed by the target. Traditional target detection mainly relies on the scattering characteristics of incident sound waves by rigid targets (such as submarines and torpedoes), and its detectability is usually measured by target intensity. Target intensity has clear physical meaning and engineering feasibility, and has been widely incorporated into sonar equations for system-level performance evaluation.

[0003] However, in real-world marine environments, underwater moving targets (especially high-speed vessels) not only generate their own scattered echoes when traversing sound propagation paths, but also create complex wake fields behind them. A target wake field refers to a series of unsteady fluid structures induced behind a target's trajectory during its movement in water due to factors such as hull disturbance, cavitation, turbulent mixing, and thermodynamic effects. These structures typically manifest as disturbances in local temperature, salinity, density, and even sound speed. Especially in environments with oceanic strata or strong stratification, wake disturbances can persist for extended periods and significantly alter the acoustic properties of the local sound propagation medium.

[0004] When the transmit / receive connection of an active sonar is covered by such a wake field, even if the target body is far away from the sound propagation path, the transmitted sound wave will still undergo complex sound propagation effects such as refraction, scattering, phase modulation, and multipath interference reconstruction due to passing through the disturbed region. This causes the sound field at the receiving end to exhibit abnormal fluctuations for several seconds to tens of seconds after the target has passed through, i.e., "wake-induced sound field anomaly". This phenomenon is essentially a medium disturbance-type sound propagation anomaly, and its physical mechanism is fundamentally different from the boundary scattering of rigid targets. The former acts on the sound velocity field of a continuous medium, while the latter acts on a discrete solid interface.

[0005] Currently, characterization methods for such wake acoustic effects mostly employ indirect indicators such as propagation loss anomalies, standard deviation of received acoustic intensity fluctuations, signal correlation attenuation, or time-frequency characteristic distortion. While these methods can reflect the existence and intensity of wake disturbances to some extent, they are difficult to compare with the target intensity of the actual target and are also difficult to directly embed into sonar equations for system-level detectability assessment.

[0006] Therefore, there is an urgent need to develop an equivalent intensity index that can convert the acoustic field changes induced by the wake of the target into an equivalent intensity index that can be directly compared with the target intensity and used for sonar equation evaluation. At the same time, this equivalent intensity index needs to be able to adapt to the multipath propagation characteristics of actual underwater acoustic channels. Summary of the Invention

[0007] In view of this, embodiments of this application propose an equivalent target intensity evaluation method for the sound field induced by the target wake field. The method aims to regard the multipath sound field changes induced by the target wake field as an equivalent scattered sound field. By referring to the definition of target intensity, an equivalent target intensity index that can be directly compared with the traditional target intensity is output.

[0008] To achieve the above objectives, embodiments of this application propose a method for evaluating the equivalent target intensity of a sound field induced by a target wake field. The method includes the following steps: establishing an underwater acoustic environment; calculating the receiver sound field before and after target intrusion in the underwater acoustic environment, and calculating the abnormal component of the receiver sound field based on the receiver sound field before and after target intrusion; pushing the abnormal component of the receiver sound field back to a distance of 1m from the equivalent sound center of the internal wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field; in a multipath environment, calculating the incident sound field at the equivalent sound center of the internal wave based on the path superposition principle; constructing the equivalent target intensity of the sound field induced by the target wake field based on the equivalent scattered sound field and the incident sound field; embedding the equivalent target intensity of the sound field induced by the target wake field into the sonar equation to conduct a detection performance evaluation.

[0009] To achieve the above objectives, embodiments of this application also propose an equivalent target intensity assessment system for the sound field induced by the target wake field. The system includes: an anomaly component calculation module, an equivalent scattered sound field calculation module, an incident sound field calculation module, an equivalent target intensity construction module, and an embedded application module. The anomaly component calculation module is used to establish an underwater acoustic environment, calculate the receiver sound field before and after target intrusion in the underwater acoustic environment, and calculate the anomaly component of the receiver sound field based on the receiver sound field before and after target intrusion. The equivalent scattered sound field calculation module is used to calculate the receiver sound field... The anomalous sound field component is pushed back to a distance of 1m from the equivalent sound center of the inner wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field; the incident sound field calculation module is used to calculate the incident sound field at the equivalent sound center of the inner wave in a multipath environment based on the principle of path superposition; the equivalent target intensity construction module is used to construct the equivalent target intensity of the sound field induced by the target wake field based on the equivalent scattered sound field and the incident sound field at the equivalent sound center of the inner wave; the embedded application module is used to embed the equivalent target intensity of the sound field induced by the target wake field into the sonar equation to carry out detection performance evaluation.

[0010] To achieve the above objectives, embodiments of this application also propose an electronic device, including: a processor and a memory storing a program, the program including instructions executable by the processor, the processor being configured to, when executing the instructions, enable the electronic device to implement an equivalent target intensity assessment method for a target wake field induced sound field as described above.

[0011] 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 an equivalent target intensity assessment method for a target wake field induced sound field as described above.

[0012] In some optional embodiments, the location of the sound source is recorded as... The location of the receiving end is The location of the equivalent sound center of the internal wave is The time variable is The frequency variable is The angular frequency variable is , The spectrum of the sound source is ;

[0013] In an underwater acoustic environment, the receiver sound field is calculated before and after the target intrusion, including:

[0014] The receiver sound pressure level before target intrusion, i.e., under conditions without wake interference, is calculated using the following formula. :

[0015] ;

[0016] in, In order to transmit signals, This indicates that a convolution calculation is being performed. The channel impulse response between the sound source and the receiver before the target intrusion;

[0017] The following formula is used to calculate the receiver sound pressure level after target intrusion, i.e., under the condition of wake influence. :

[0018] ;

[0019] in, The channel impulse response between the sound source and the receiver after the target intrusion;

[0020] Using the following formulas, respectively and Perform a Fourier transform to obtain the receiver's sound field before and after the target intrusion:

[0021] ;

[0022] ;

[0023] in, The sound field at the receiving end before the target intrusion. The sound field at the receiving end after the target intrusion. It is the imaginary unit.

[0024] In some optional embodiments, the abnormal components of the receiver's sound field are calculated based on the receiver's sound field before and after the target intrusion, using the following formula:

[0025] ;

[0026] in, This refers to the anomalous components of the sound field at the receiving end.

[0027] In some optional embodiments, the anomalous component of the receiver's sound field is pushed back to a distance of 1 m from the equivalent sound center of the internal wave, thereby converting the target wake field-induced sound field into an equivalent scattered sound field, including:

[0028] Will The equivalent scattered sound field is considered to be radiated by a virtual scatterer, and the equivalent scattered sound field at a distance of 1m from the equivalent sound center of the internal wave is defined as follows: ;

[0029] Based on the sound propagation model, calculate the channel response function from the equivalent sound center of the internal wave to the receiver. ;

[0030] Using the following formula, cylindrical expansion pairs By backtracking, we obtain for:

[0031] ;

[0032] in, This is the distance between the equivalent sound center of the internal wave and the receiving end.

[0033] In some optional embodiments, based on the principle of path superposition, the incident sound field at the equivalent sound center of the inner wave is calculated using the following formula:

[0034] ;

[0035] ;

[0036] in, The frequency spectrum of the sound source. Let be the channel response function from the sound source to the equivalent sound center of the internal wave. The total number of valid paths. and The first The amplitude and propagation delay of each effective path, The incident sound field is located at the center of the internal wave equivalent sound.

[0037] In some optional embodiments, the equivalent target intensity of the target wake-induced sound field is constructed based on the equivalent scattered sound field and the incident sound field, including:

[0038] Referring to the underwater acoustic target intensity formula, the equivalent target intensity of the sound field induced by the target wake field is calculated. The ratio of the equivalent scattered sound field to the incident sound field is constructed and its logarithm is taken. The expression is:

[0039] .

[0040] In some optional embodiments, the equivalent target intensity of the acoustic field induced by the target wake field is embedded in the sonar equations to conduct a detection effectiveness assessment, achieved through the following formula:

[0041] ;

[0042] in, For signal-to-noise ratio, The sound source level represents the power of the sound source. To spread the loss, The equivalent target intensity of the sound field induced by the target wake field is abbreviation, The noise level represents the power of the background noise received at the receiver. This is the directional index of the receiving end.

[0043] This application proposes a method for evaluating the equivalent target intensity of the acoustic field induced by a target wake field. Addressing the difficulty in measuring changes in the acoustic field induced by a target wake field using traditional target intensity methods and in assessing underwater acoustic detectability, this method constructs anomaly components of the receiver's acoustic field based on the receiver's acoustic field before and after target intrusion. Through backpropagation and multipath cylindrical extension correction, these anomaly components are backpropagated to a distance of 1 m from the equivalent sound center of the internal wave, thus converting the target wake field induced by the acoustic field into an equivalent scattered acoustic field. Then, based on the equivalent scattered acoustic field and the incident acoustic field at the equivalent sound center of the internal wave, the equivalent target intensity of the target wake field induced by the acoustic field is constructed. Finally, the constructed equivalent target intensity of the target wake field induced by the acoustic field is embedded into the sonar equations for detection performance evaluation. This method effectively improves the quantitative evaluation of the "acoustic disturbance capability" of a target wake field and possesses strong engineering applicability. Attached Figure Description

[0044] 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. 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.

[0045] Figure 1 This is a flowchart of an equivalent target intensity assessment method for a target wake field induced sound field provided in one embodiment of this application;

[0046] Figure 2 This is a detailed schematic diagram of an equivalent target intensity assessment method for a target wake field induced sound field provided in one embodiment of this application;

[0047] Figure 3 This is a schematic diagram of the vertical distribution of seawater stratification provided in one embodiment of this application;

[0048] Figure 4 This is a schematic diagram of the wake disturbance sound velocity profile provided in one embodiment of this application;

[0049] Figure 5 This is a schematic diagram of the propagation trajectory of wake disturbance sound rays provided in one embodiment of this application;

[0050] Figure 6 This is a schematic diagram illustrating the changes in the acoustic field induced by the wake field in one embodiment of this application;

[0051] Figure 7 This is a schematic diagram of the distribution of equivalent target intensity along the pitch angle provided in one embodiment of this application;

[0052] Figure 8 This is a schematic diagram of the structure of an equivalent target intensity assessment system for a target wake field induced sound field provided in another embodiment of this application;

[0053] Figure 9 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application. Detailed Implementation

[0054] 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.

[0055] One embodiment of this application proposes an equivalent target intensity evaluation method for a sound field induced by a target wake field. The implementation details of the equivalent target intensity evaluation method for a sound field induced by a target wake field proposed in this embodiment are described below. The following implementation details are provided for ease of understanding and are not necessary for implementing this solution.

[0056] The specific process of the equivalent target intensity assessment method for the sound field induced by the target wake field proposed in this embodiment can be as follows: Figure 1 As shown, its visual details can be as follows Figure 2 As shown, the method includes:

[0057] Step 11: Establish an underwater acoustic environment. Under the underwater acoustic environment, calculate the receiver sound field before and after the target intrusion, and calculate the receiver sound field anomalous components based on the receiver sound field before and after the target intrusion.

[0058] In practical implementation, to assess the equivalent target intensity of the acoustic field induced by the target wake field, it is necessary to determine the acoustic field induced by the target wake field. For underwater acoustic detection scenarios, we establish an underwater acoustic environment. Under this environment, we calculate the receiver acoustic field before and after the target intrusion, and calculate the abnormal components of the receiver acoustic field based on these fields. We treat the target wake field as an equivalent target, thus considering the abnormal components of the receiver acoustic field as an equivalent scattered sound field.

[0059] In one example, we denote the location of the sound source as... The location of the receiving end is The location of the equivalent sound center of the internal wave is The time variable is The frequency variable is The angular frequency variable is , The spectrum of the sound source is .

[0060] To calculate the receiver sound field before and after the target intrusion, we must first calculate the receiver sound pressure before the target intrusion (i.e., the receiver sound pressure under the condition of no wake influence) and the receiver sound pressure after the target intrusion (i.e., the receiver sound pressure under the condition of wake influence).

[0061] Pre-intrusion receiver sound pressure It is calculated using the following formula:

[0062] ;

[0063] in, In order to transmit signals, This indicates that a convolution calculation is being performed. The channel impulse response between the sound source and the receiver before the target intrusion.

[0064] Sound pressure at the receiver after target intrusion It is calculated using the following formula:

[0065] ;

[0066] in, The channel impulse response between the sound source and the receiver after the target intrusion.

[0067] In the calculation and Then, the following formulas can be used to respectively... and Perform a Fourier transform to obtain the receiver's sound field before and after the target intrusion:

[0068] ;

[0069] ;

[0070] in, The sound field at the receiving end before the target intrusion. The sound field at the receiving end after the target intrusion. It is the imaginary unit.

[0071] In one example, the abnormal components of the receiver's sound field are calculated based on the receiver's sound field before and after the target intrusion, using the following formula:

[0072] ;

[0073] in, This refers to the anomalous components of the sound field at the receiving end.

[0074] Step 12: Push the abnormal sound field component of the receiver back to a distance of 1m from the equivalent sound center of the internal wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field.

[0075] In practice, after calculating the abnormal sound field components at the receiving end, the abnormal sound field components at the receiving end can be pushed back to a distance of 1m from the equivalent sound center of the internal wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field.

[0076] In one example, we will The equivalent scattered sound field is considered to be radiated by a virtual scatterer, and the equivalent scattered sound field at a distance of 1m from the equivalent sound center of the internal wave is defined as follows: .

[0077] Next, based on the sound propagation model, the channel response function from the equivalent sound center of the internal wave to the receiver is calculated. A sound propagation model is a mathematical model that calculates the transmission of sound from a sound source to a receiver using physical equations in a given underwater acoustic environment. Its direct products are usually the sound field and propagation loss.

[0078] Finally, the cylindrical expansion is applied using the following formula. By backtracking, we obtain for:

[0079] ;

[0080] in, This is the distance between the equivalent sound center of the internal wave and the receiving end.

[0081] Through the aforementioned backpropagation and multipath cylindrical expansion correction, the target wake field-induced sound field was successfully converted into an equivalent scattered sound field, laying the foundation for the subsequent construction of the equivalent target intensity.

[0082] Step 13: In a multipath environment, calculate the incident sound field at the equivalent sound center of the internal wave based on the principle of path superposition.

[0083] In the specific implementation, in the process of constructing the equivalent target intensity of the sound field induced by the target wake field, in addition to obtaining the equivalent scattered sound field of the sound field induced by the target wake field, it is also necessary to calculate the incident sound field at the equivalent sound center of the internal wave in a multipath environment based on the principle of path superposition.

[0084] In one example, based on the principle of path superposition, the incident sound field at the equivalent sound center of the inner wave can be calculated using the following formula:

[0085] ;

[0086] ;

[0087] in, The frequency spectrum of the sound source. Let be the channel response function from the sound source to the equivalent sound center of the internal wave. The total number of valid paths. and The first The amplitude and propagation delay of each effective path, The incident sound field is located at the center of the internal wave equivalent sound.

[0088] Step 14: Based on the equivalent scattered sound field and the incident sound field, construct the equivalent target intensity of the sound field induced by the target wake field.

[0089] In practical implementation, after obtaining the equivalent scattered sound field and the incident sound field, the equivalent target intensity of the sound field induced by the target wake field can be constructed based on the equivalent scattered sound field and the incident sound field.

[0090] In one example, we refer to the underwater acoustic target intensity formula to calculate the equivalent target intensity of the acoustic field induced by the target wake field. The ratio of the equivalent scattered sound field to the incident sound field is constructed and its logarithm is taken. The expression is:

[0091] .

[0092] Step 15: Embed the equivalent target intensity of the acoustic field induced by the target wake field into the sonar equation to conduct a detection performance assessment.

[0093] In this specific implementation, the purpose of this embodiment is to solve the problem that the changes in the acoustic field induced by the target wake field are difficult to measure using traditional target intensity and difficult to assess underwater acoustic detectability. Therefore, after constructing the equivalent target intensity of the acoustic field induced by the target wake field, we need to embed the equivalent target intensity of the acoustic field induced by the target wake field into the sonar equation to carry out detection performance evaluation and improve the effect of detection performance evaluation.

[0094] In one example, the equivalent target intensity of the acoustic field induced by the target wake field is embedded into the sonar equations to conduct a detection effectiveness assessment, which is achieved through the following formula:

[0095] ;

[0096] in, For signal-to-noise ratio, The sound source level represents the power of the sound source. To spread the loss, The equivalent target intensity of the sound field induced by the target wake field is abbreviation, The noise level represents the power of the background noise received at the receiver. This is the directional index of the receiving end.

[0097] Signal-to-noise ratio Signal-to-noise ratio (SNR) represents the ratio of the power of the target echo signal received by the receiver to the power of the background noise, usually expressed in decibels (dB). SNR is an important indicator of a sonar system's ability to detect targets; a higher SNR indicates a stronger target detection capability.

[0098] Sound source level The sound level represents the power of the sound waves emitted by the sound source (the transmitting end of the sonar system). It is usually expressed as the root mean square value of decibels (dB) relative to 1 micropascal (μPa). The higher the sound source level, the greater the power of the sound waves emitted by the sound source and the farther the propagation distance.

[0099] transmission loss Propagation loss represents the power loss of a sound wave during propagation due to diffusion, absorption, scattering, etc., and is usually expressed in decibels (dB). Propagation loss is related to factors such as the propagation distance, the propagation medium, and the frequency of the sound wave. In the active sonar equation, since the sound wave needs to travel back and forth between the transmitter and receiver, the propagation loss needs to be calculated twice.

[0100] Noise level , represents the background noise power received by the receiver, usually expressed in decibels (dB). Background noise may come from the marine environment, the atmospheric environment, and the noise of the sonar system itself. Total noise is one of the important factors affecting the sonar system's ability to detect targets. The higher the noise level, the weaker the sonar system's ability to detect targets.

[0101] Receiver directivity index Also known as array gain, it represents the signal gain obtained by a sonar system through array processing (such as beamforming and coherent superposition), usually expressed in decibels (dB). Array gain can increase the power of the target echo signal received by the sonar system, thereby improving the detection capability of the sonar system.

[0102] This embodiment proposes an equivalent target intensity assessment method for the acoustic field induced by a target wake field. Addressing the difficulty in measuring changes in the acoustic field induced by a target wake field using traditional target intensity methods and in assessing underwater acoustic detectability, this method constructs anomaly components of the receiver's acoustic field based on the receiver's acoustic field before and after target intrusion. Through backpropagation and multipath cylindrical expansion correction, these anomaly components are backpropagated to a distance of 1 m from the equivalent sound center of the internal wave, thus converting the target wake field induced acoustic field into an equivalent scattered acoustic field. Based on the equivalent scattered acoustic field and the incident acoustic field at the equivalent sound center of the internal wave, the equivalent target intensity of the target wake field induced acoustic field is constructed. Finally, the constructed equivalent target intensity of the target wake field induced acoustic field is embedded into the sonar equations for detection performance evaluation. This method effectively improves the quantitative assessment of the "acoustic disturbance capability" of a target wake field and possesses strong engineering applicability.

[0103] The steps described above are merely for clarity in describing the technical solution. In actual implementation, they can be combined into one step, or certain 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. Any insignificant modifications or designs added to the algorithm or process, as long as they do not change the core of the algorithm or process, are also within the scope of protection of this application.

[0104] In one embodiment, to verify the effectiveness of the equivalent target intensity assessment method for the sound field induced by the target wake field proposed in this application, we conducted relevant simulation experiments.

[0105] Simulation conditions are set based on typical shallow sea environments; ocean stratification conditions can be achieved as follows: Figure 3 As shown, the depth of the mezzanine center is 40m, and the mezzanine thickness and maximum strength are 40m and 0.22kg / m4, respectively. The depth of both the sound source and receiver is 20m, the sound wave frequency is 1kHz, and the target wake field moves at a constant speed of 2kn behind the target along the direction of motion, perpendicularly crossing the transmitter-receiver connection. Taking the wake field 500m after the target crosses the transmitter-receiver connection as an example, the sound velocity profile after disturbance is calculated sequentially (…). Figure 4 ), the sound pressure field without internal wave and the sound pressure field under the influence of wake.

[0106] Local acoustic ray trajectories without wake field disturbance and with wake field disturbance are as follows: Figure 5 As shown, when the sound wave passes through the wake field of the target, it is caused by... The position begins to deflect significantly upwards and diagonally, causing changes in the reconstruction of the interference structure and propagation loss along the sound propagation direction. This phenomenon can be represented by the superposition of the stable background field and the equivalent scattered sound field. At this point, the sound field change induced by the target wake is the equivalent scattered sound field, and its result can be as follows: Figure 6 As shown. Extract The sound pressure field at a point is calculated, and the sound field change at a distance of 300m along the direction of sound propagation is extracted to calculate the equivalent target intensity. (See reference...) Figure 7 It can be seen that the equivalent target intensity of the wake field of the target takes the maximum value of 17.84 dB at -3°, and there is a basic distribution pattern of "high in the center and low on both sides" along the scattering angle.

[0107] Another embodiment of this application proposes an equivalent target intensity evaluation system for the sound field induced by a target wake field. The details of this equivalent target intensity evaluation system are described below. The following implementation details are provided for ease of understanding and are not essential for implementing this solution. Figure 8 This is a schematic diagram of the structure of an equivalent target intensity assessment system for a target wake field induced sound field proposed in this embodiment, including: anomaly component calculation module 21, equivalent scattered sound field calculation module 22, incident sound field calculation module 23, equivalent target intensity construction module 24, and embedded application module 25.

[0108] The abnormal component calculation module 21 is used to establish an underwater acoustic environment. Under the underwater acoustic environment, the receiver sound field before and after the target intrusion is calculated respectively, and the abnormal component of the receiver sound field is calculated based on the receiver sound field before and after the target intrusion.

[0109] The equivalent scattered sound field calculation module 22 is used to push back the abnormal components of the sound field at the receiving end to a distance of 1m from the equivalent sound center of the internal wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field.

[0110] The incident sound field calculation module 23 is used to calculate the incident sound field at the equivalent sound center of the internal wave in a multipath environment based on the principle of path superposition.

[0111] The equivalent target intensity construction module 24 is used to construct the equivalent target intensity of the sound field induced by the target wake field based on the equivalent scattered sound field and the incident sound field at the equivalent sound center of the internal wave.

[0112] The embedded application module 25 is used to embed the equivalent target intensity of the sound field induced by the target wake field into the sonar equation to conduct a detection performance evaluation.

[0113] It is worth noting that all modules involved in this embodiment are logical modules. In practical applications, a logical module can be a physical module, a part of a physical module, or an organic combination of multiple physical modules. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce modules that are not closely related to solving the technical problems proposed in this application. However, this does not mean that other modules are absent from this embodiment.

[0114] 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.

[0115] Another embodiment of this application provides an electronic device, such as Figure 9 As shown, it includes: a processor 31 and a memory 32 storing a program, the program including instructions that the processor 31 can execute, the processor 31 being configured to, when executing the instructions, enable the electronic device to implement an equivalent target intensity assessment method for a target wake field induced sound field as described in the above method embodiment.

[0116] The memory and processor are connected via a bus, which includes any number of interconnecting buses and bridges. The bus connects various circuits of one or more processors and memories. 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 element or multiple elements, 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.

[0117] 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.

[0118] Another embodiment of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, can implement an equivalent target intensity assessment method for a target wake field induced sound field as described in the above method embodiments.

[0119] 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.

[0120] It will be understood by those skilled in the art that the above embodiments are specific implementations of this application, and various changes in form and detail can be made in practical applications 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 method for evaluating the equivalent target intensity of a sound field induced by a target wake field, characterized in that, include: Establish an underwater acoustic environment, and calculate the receiver sound field before and after the target intrusion in the underwater acoustic environment, and calculate the abnormal components of the receiver sound field based on the receiver sound field before and after the target intrusion. The abnormal sound field component of the receiver is pushed back to a distance of 1m from the equivalent sound center of the internal wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field. In a multipath environment, the incident sound field at the equivalent sound center of the internal wave is calculated based on the principle of path superposition. Based on the equivalent scattered sound field and the incident sound field, the equivalent target intensity of the sound field induced by the target wake field is constructed. The equivalent target intensity of the acoustic field induced by the target wake field is embedded into the sonar equation to conduct a detection performance assessment.

2. The method for evaluating the equivalent target intensity of the acoustic field induced by the target wake field according to claim 1, characterized in that, The location of the sound source is recorded as The location of the receiving end is The location of the equivalent sound center of the internal wave is The time variable is The frequency variable is The angular frequency variable is , The spectrum of the sound source is ; In an underwater acoustic environment, the receiver sound field is calculated before and after the target intrusion, including: The receiver sound pressure level before target intrusion, i.e., under conditions without wake interference, is calculated using the following formula. : ； in, In order to transmit signals, This indicates that a convolution calculation is being performed. The channel impulse response between the sound source and the receiver before the target intrusion; The following formula is used to calculate the receiver sound pressure level after target intrusion, i.e., under the condition of wake influence. : ； in, The channel impulse response between the sound source and the receiver after the target intrusion; Using the following formulas, respectively and Perform a Fourier transform to obtain the receiver's sound field before and after the target intrusion: ； ； in, The sound field at the receiving end before the target intrusion. The sound field at the receiving end after the target intrusion. It is the imaginary unit.

3. The method for evaluating the equivalent target intensity of the acoustic field induced by the target wake field according to claim 2, characterized in that, The abnormal components of the receiver's sound field are calculated based on the receiver's sound field before and after the target intrusion, using the following formula: ； in, This refers to the anomalous components of the sound field at the receiving end.

4. The method for evaluating the equivalent target intensity of the acoustic field induced by the target wake field according to claim 3, characterized in that, The abnormal sound field component at the receiving end is pushed back to a distance of 1m from the equivalent sound center of the internal wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field, including: Will The equivalent scattered sound field is considered to be radiated by a virtual scatterer, and the equivalent scattered sound field at a distance of 1m from the equivalent sound center of the internal wave is defined as follows: ; Based on the sound propagation model, calculate the channel response function from the equivalent sound center of the internal wave to the receiver. ; Using the following formula, cylindrical expansion pairs By backtracking, we obtain for: ； in, This is the distance between the equivalent sound center of the internal wave and the receiving end.

5. The method for evaluating the equivalent target intensity of the acoustic field induced by the target wake field according to claim 4, characterized in that, Based on the principle of path superposition, the incident sound field at the equivalent sound center of the inner wave is calculated using the following formula: ； ； in, The frequency spectrum of the sound source. Let be the channel response function from the sound source to the equivalent sound center of the internal wave. The total number of valid paths. and The first The amplitude and propagation delay of each effective path, The incident sound field is located at the center of the internal wave equivalent sound.

6. A method for evaluating the equivalent target intensity of a sound field induced by a target wake field according to any one of claims 1 to 5, characterized in that, Based on the equivalent scattered sound field and the incident sound field, the equivalent target intensity of the sound field induced by the target wake field is constructed, including: Referring to the underwater acoustic target intensity formula, the equivalent target intensity of the sound field induced by the target wake field is calculated. The ratio of the equivalent scattered sound field to the incident sound field is constructed and its logarithm is taken. The expression is: 。 7. The method for evaluating the equivalent target intensity of the acoustic field induced by the target wake field according to claim 6, characterized in that, The equivalent target intensity of the acoustic field induced by the target wake field is embedded into the sonar equation to conduct a detection effectiveness assessment, which is achieved through the following formula: ； in, For signal-to-noise ratio, The sound source level represents the power of the sound source. To spread the loss, The equivalent target intensity of the sound field induced by the target wake field is abbreviation, The noise level represents the power of the background noise received at the receiver. This is the directional index of the receiving end.

8. An equivalent target intensity assessment system for a sound field induced by a target wake field, characterized in that, include: The abnormal component calculation module is used to establish an underwater acoustic environment. Under the underwater acoustic environment, the receiver sound field before and after the target intrusion is calculated respectively, and the abnormal component of the receiver sound field is calculated based on the receiver sound field before and after the target intrusion. The equivalent scattered sound field calculation module is used to push back the abnormal components of the sound field at the receiving end to a distance of 1m from the equivalent sound center of the internal wave, thereby converting the sound field induced by the target wake field into an equivalent scattered sound field. The incident sound field calculation module is used to calculate the incident sound field at the equivalent sound center of the internal wave in a multipath environment based on the principle of path superposition. The equivalent target intensity construction module is used to construct the equivalent target intensity of the sound field induced by the target wake field based on the equivalent scattered sound field and the incident sound field at the equivalent sound center of the internal wave. An embedded application module is used to embed the equivalent target intensity of the acoustic field induced by the target wake field into the sonar equation to conduct a detection performance assessment.

9. An electronic device, characterized in that, include: A processor and a memory storing a program, the program including instructions executable by the processor, the processor being configured to, when executing the instructions, enable the electronic device to implement an equivalent target intensity assessment method for a target wake field induced sound field as claimed 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 an equivalent target intensity assessment method for the sound field induced by the target wake field as described in any one of claims 1 to 7.

Images