Continuous wave sonar direct wave suppression method, device and equipment and storage medium

Abstract

The invention provides a continuous wave sonar direct wave suppression method, device and equipment and a storage medium, and the method comprises the steps: intercepting a target segment signal from a received signal, the target segment signal being composed of continuous Nw sampling points in the received signal; an estimation channel corresponding to the target segment signal is solved through a basis tracking algorithm, a dictionary matrix of the basis tracking algorithm is an Nw * Nw Toeplitz matrix, the first column is the first to Nw sampling points of the transmitted signal, and the second to Nw elements of the first row are zero; if the current estimation channel meets a judgment condition, the current estimation channel is determined as a final channel, and the judgment condition includes that the maximum element value in the estimation channel is larger than a first threshold value; reconstructing a direct wave and a multipath signal thereof according to the transmitted signal and the final channel; and subtracting the direct wave and the multipath signal thereof from the received signal to obtain a suppression result. According to the invention, on the premise of ensuring that the target echo energy is not lost, the sidelobe interference of the direct wave is effectively eliminated.

Description

Technical Field

[0001] The present application relates to the technical field of active sonar signal processing, and in particular to a method, device, equipment and storage medium for suppressing direct waves of continuous wave sonar. Background Art

[0002] Continuous-wave sonar plays a key role in underwater detection, marine resource exploration, and underwater vehicle navigation. However, during continuous-wave sonar operation, the direct wave, generated by the transmitted signal propagating directly to the receiver, is a serious source of interference. Due to its short propagation path and minimal propagation loss, the direct wave's intensity is often much greater than the target's echo signal. This easily drowns out the target's echo signal, making it difficult for the sonar system to accurately detect and identify the target, significantly limiting the detection performance of continuous-wave sonar.

[0003] Existing methods for suppressing direct waves in continuous wave sonar mainly include time-domain filtering methods and spatial-domain filtering methods. Time-domain filtering methods, such as adaptive filtering technology, may filter out target echo signals when dealing with strong direct wave interference due to the strong correlation between the direct wave and the target echo. Spatial-domain filtering methods, such as beam nulling methods and acoustic shielding technology, apply beam nulling to the signal in the direction of the direct wave, but it is difficult to eliminate the sidelobe interference of the direct wave, and the direct wave suppression capability of this method is limited. All of the above methods are difficult to effectively achieve direct wave suppression in continuous wave sonar. Summary of the Invention

[0004] The present application provides a method, device, equipment and storage medium for suppressing direct waves in a continuous wave sonar, which can solve the technical problem that it is difficult to effectively achieve direct wave suppression in a continuous wave sonar in the prior art.

[0005] In a first aspect, an embodiment of the present application provides a method for suppressing direct waves from a continuous wave sonar, the method comprising: A new target segment signal is intercepted from the received signal, wherein the target segment signal is composed of N consecutive segments in the received signal. w Sampling points The estimated channel corresponding to the target segment signal is solved by the basis pursuit algorithm, where the dictionary matrix of the basis pursuit algorithm is N w ×N w The Toeplitz matrix, the first column is the 1st to Nth column of the transmitted signal w sampling points, the 2nd to Nth sampling points in the first row w elements are all zero; If the current estimated channel meets the judgment condition, the current estimated channel is determined as the final channel, otherwise the process returns to executing the method of intercepting a new target segmented signal from the received signal, wherein the judgment condition includes: the maximum element value in the estimated channel is greater than the first threshold; Reconstruct the direct wave and its multipath signals based on the transmitted signal and the final channel; The suppression result is obtained by subtracting the direct wave and its multipath signals from the received signal.

[0006] Furthermore, in one embodiment, the step of intercepting a new target segment signal from the received signal includes: The target segment signal corresponding to the sliding window is intercepted from the received signal, where the size of the sliding window is N w The initial target segment signal is the 1st to Nth segment of the received signal. w sampling points; The returning step of intercepting a new target segmented signal from the received signal includes: Move the sliding window backward N step sampling points, and returns the target segmented signal corresponding to the sliding window intercepted from the received signal, wherein N step <N w .

[0007] Furthermore, in one embodiment, the judgment condition further includes: the sequence number of the maximum value element in the estimated channel is less than or equal to N step .

[0008] Furthermore, in one embodiment, the first threshold is set based on the relationship between the amplitudes of the transmitted signal and the received signal.

[0009] Furthermore, in one embodiment, ,in, 、 are the minimum and maximum delays of the direct wave and its multipath signal received in the underwater multipath channel, respectively. s is the sampling rate of the received signal.

[0010] Furthermore, in one embodiment, solving the estimated channel corresponding to the target segmented signal using a basis pursuit algorithm includes: Will , z and u are initialized to N w ×1 zero vector, initializing the number of iterations to zero; Increase the number of iterations by one and update , z and u: , , , Among them, A is the dictionary matrix, I is N w ×N w The identity matrix, is the target segment signal, represents the conjugate transpose of the matrix, ρ is the penalty coefficient, λ is the regularization coefficient, i=1,2,…, N w ; If the number of iterations is less than the upper limit of iterations, and , then return to execute the above and increase the number of iterations by one, update , z and u, otherwise stop the iteration and set the current As the estimated channel corresponding to the target segment signal, represents the 2-norm, and e2 is the second threshold.

[0011] Furthermore, in one embodiment, reconstructing the direct wave and its multipath signal based on the transmitted signal and the final channel includes: Pad the transmitted signal and the final channel with zeros to obtain the first zero-padding result and the second zero-padding result: , , in, is the first zero-filling result, is the second zero-filling result, s is the transmitted signal, For the final channel, represents the matrix conjugate transpose, N y is the number of sampling points of the received signal, N s is the number of sampling points of the transmitted signal, N start N is the serial number of the first sampling point of the target segment signal in the received signal. end is the sequence number of the last sampling point of the target segment signal in the received signal; Perform linear convolution on the first zero-padding result and the second zero-padding result to obtain the convolution result: , in, is the convolution result, represents linear convolution; Extract the direct wave and its multipath signals from the convolution result: , in, It is a direct wave and its multipath signal.

[0012] In a second aspect, an embodiment of the present application further provides a continuous wave sonar direct wave suppression device, the continuous wave sonar direct wave suppression device comprising: The interception module is used to intercept a new target segment signal from the received signal, wherein the target segment signal is composed of N consecutive w Sampling points The solution module is used to solve the estimated channel corresponding to the target segment signal through the basis pursuit algorithm, where the dictionary matrix of the basis pursuit algorithm is N w ×N w The Toeplitz matrix, the first column is the 1st to Nth column of the transmitted signal w sampling points, the 2nd to Nth sampling points in the first row w elements are all zero; a judgment module, configured to determine the current estimated channel as the final channel if the current estimated channel satisfies a judgment condition, and otherwise return to executing the step of intercepting a new target segmented signal from the received signal, wherein the judgment condition includes: a maximum element value in the estimated channel is greater than a first threshold; A reconstruction module, used for reconstructing the direct wave and its multipath signals according to the transmitted signal and the final channel; The elimination module is used to subtract the direct wave and its multipath signals from the received signal to obtain a suppression result.

[0013] In a third aspect, an embodiment of the present application further provides a continuous wave sonar direct wave suppression device, which includes a processor, a memory, and a continuous wave sonar direct wave suppression program stored in the memory and executable by the processor, wherein when the continuous wave sonar direct wave suppression program is executed by the processor, the steps of the above-mentioned continuous wave sonar direct wave suppression method are implemented.

[0014] In a fourth aspect, an embodiment of the present application further provides a storage medium, on which a continuous wave sonar direct wave suppression program is stored, wherein when the continuous wave sonar direct wave suppression program is executed by a processor, the steps of the above-mentioned continuous wave sonar direct wave suppression method are implemented.

[0015] In the present application, a dictionary matrix of a basis pursuit algorithm is constructed with the aid of the transmitted signal, and the received signal is segmented and intercepted. The estimated channel corresponding to the intercepted segmented signal is solved by the basis pursuit algorithm. When the maximum element value of the estimated channel is greater than a first threshold, the estimated channel is determined as the final channel. The direct wave and its multipath signal are reconstructed according to the transmitted signal and the final channel, and the direct wave and its multipath signal are subtracted from the received signal to obtain the suppression result. By utilizing the sparse characteristics of the underwater channel, the accuracy of the basis pursuit algorithm solution can be ensured. By using part of the information in the received signal to solve the estimated channel, the energy loss of the target echo can be reduced, the direct wave interference is eliminated in the time domain, and the sidelobe interference of the direct wave can be effectively suppressed. Through the present application, the sidelobe interference of the direct wave can be effectively eliminated while ensuring that the target echo energy is not lost, and the direct wave sidelobe is suppressed to the background noise level. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the flow of a method for suppressing direct waves of continuous wave sonar in one embodiment of the present application; Figure 2 This is a comparison diagram of the actual channel and the final channel in the simulation experiment; Figure 3 It is the time-frequency diagram of the received signal in the simulation experiment; Figure 4 It is the time-frequency diagram of the inhibition results in the simulation experiment; Figure 5 This is the Doppler velocity diagram of the received signal, target echo and background noise in the simulation experiment; Figure 6 The suppression results, target echo and background noise Doppler velocity diagram in the simulation experiment; Figure 7 This is a schematic diagram of the functional modules of a continuous wave sonar direct wave suppression device in one embodiment of the present application; Figure 8 This is a schematic diagram of the hardware structure of the continuous wave sonar direct wave suppression device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0019] In a first aspect, an embodiment of the present application provides a method for suppressing direct waves of continuous wave sonar.

[0020] Figure 1 A flow chart of a method for suppressing direct waves of continuous wave sonar in one embodiment of the present application is shown.

[0021] Reference Figure 1 In one embodiment, a method for suppressing direct waves of continuous wave sonar includes the following steps: S1, intercepting a new target segment signal from the received signal, wherein the target segment signal is composed of N consecutive w The sampling points are composed of

[0022] For example, the received signal is , The target segment signal is , Among them, N yis the number of sampling points of the received signal, It is represented as a matrix with m rows and n columns. In the following formulas, the matrix subscript is omitted for convenience. represents matrix transpose, N start N is the serial number of the first sampling point of the target segment signal in the received signal. end N is the serial number of the last sampling point of the target segment signal in the received signal. end =N start +N w -1.

[0023] S2. Solve the estimated channel corresponding to the target segment signal through the basis pursuit algorithm, where the dictionary matrix of the basis pursuit algorithm is N w ×N w The Toeplitz matrix, the first column is the 1st to Nth column of the transmitted signal w sampling points, the 2nd to Nth sampling points in the first row w elements are all zero.

[0024] For example, the transmitted signal is , The dictionary matrix is for: , Among them, N s is the number of sampling points of the transmitted signal.

[0025] Assume that the real underwater channel is , the estimated channel is , the problem that the basis pursuit algorithm needs to solve is expressed as: , Where λ is the regularization coefficient, represents the 2-norm, represents the 1-norm.

[0026] It should be noted that the sampling rates of the transmitted signal and the received signal may be the same or different, and the sampling points with the same sequence number in the transmitted signal and the received signal may be the same or different, and this application does not impose any limitation on this.

[0027] Optionally, the specific solution process of the basis pursuit algorithm can be selected as needed, and this application does not limit this.

[0028] S3. If the current estimated channel meets the judgment condition, the current estimated channel is determined as the final channel. Otherwise, the process returns to executing the method of intercepting a new target segmented signal from the received signal, wherein the judgment condition includes: the maximum element value in the estimated channel is greater than the first threshold.

[0029] It can be understood that different estimated channels will be solved based on different target segment signals. Only the estimated channels that meet the judgment conditions can be used as the final channels and used to reconstruct the direct wave and its multipath signals in subsequent steps.

[0030] Specifically, "the maximum element value in the estimated channel is greater than the first threshold" is the most basic judgment condition, which is used to ensure the reliability of the final channel.

[0031] Optionally, other sub-conditions may be added to the judgment condition to form a logical AND relationship with "the maximum element value in the estimated channel is greater than the first threshold value", thereby achieving other additional beneficial effects.

[0032] S4. Reconstruct the direct wave and its multipath signal based on the transmitted signal and the final channel.

[0033] It can be understood that based on the knowledge of the transmitted signal and the direct wave transmission channel (ie, the final channel), combined with relevant technologies in this field, the direct wave and its multipath signals can be reconstructed.

[0034] Optionally, the specific reconstruction process of the direct wave and its multipath signal can be selected as needed, and this application does not limit this.

[0035] S5. Subtract the direct wave and its multipath signal from the received signal to obtain a suppression result.

[0036] In this embodiment, a dictionary matrix for a basis pursuit algorithm is constructed using the transmitted signal, and the received signal is segmented. The estimated channel corresponding to the segmented signal is solved using the basis pursuit algorithm. When the maximum element value of the estimated channel exceeds a first threshold, the estimated channel is determined as the final channel. The direct wave and its multipath signals are reconstructed based on the transmitted signal and the final channel, and the suppression result is obtained by subtracting the direct wave and its multipath signals from the received signal. The sparse nature of the underwater channel ensures the accuracy of the basis pursuit algorithm. Solving the estimated channel using partial information from the received signal reduces energy loss in the target echo, eliminates direct wave interference in the time domain, and effectively suppresses direct wave sidelobe interference. This embodiment effectively eliminates direct wave sidelobe interference while ensuring that the target echo energy is not lost, suppressing the direct wave sidelobes to the background noise level.

[0037] Furthermore, in one embodiment, the step of intercepting a new target segment signal from the received signal includes: The target segment signal corresponding to the sliding window is intercepted from the received signal, where the size of the sliding window is N w The initial target segment signal is the 1st to Nth segment of the received signal. w sampling points; The returning step of intercepting a new target segmented signal from the received signal includes: Move the sliding window backward N step sampling points, and returns the target segmented signal corresponding to the sliding window intercepted from the received signal, wherein N step <N w .

[0038] In this embodiment, the target segment signal is intercepted by sliding the window, which is easy to operate and can flexibly set the sliding step size N according to the requirements of solution accuracy and solution time. step ,Generally speaking, the larger the sliding step size, the shorter the solution time, and the smaller the sliding step size, the higher the solution accuracy.

[0039] For example, the received signal can be intercepted up to W num segment signal, ,in, Indicates rounding down. Let the data segment number be W count , W count Initialized to zero, , before re-intercepting the target segment signal each time, let .

[0040] Optionally, N w =2*N step .

[0041] Furthermore, in one embodiment, the first threshold is set based on the relationship between the amplitudes of the transmitted signal and the received signal.

[0042] It can be understood that the basic condition that the first threshold should meet is that the first threshold is smaller than the amplitude of the actual transmission channel of the direct wave and much larger than the amplitude of the background noise.

[0043] Specifically in actual operation, due to different underwater environments and different sonar transmission signal source levels, the first threshold needs to be adjusted with reference to these factors. These factors will be reflected in the amplitude relationship between the transmitted signal and the received signal. Therefore, the first threshold can be set with reference to the amplitude relationship between the transmitted signal and the received signal.

[0044] Assuming a specific underwater environment and a specific transmitted signal are known, it's reasonable to use value A as the first threshold. If the conditions change and the amplitude of the transmitted or received signal changes, value A can be appropriately adjusted to obtain a new value B as the first threshold. For example, if the amplitude of the transmitted signal remains essentially unchanged before and after the change in conditions, while the amplitude of the received signal decreases, the first threshold should also be appropriately reduced.

[0045] Furthermore, in one embodiment, the judgment condition further includes: the sequence number of the maximum value element in the estimated channel is less than or equal to N step .

[0046] In this embodiment, if the sequence number of the maximum value element in the estimated channel is greater than N step , the sliding window will continue to move backward and re-solve the estimated channel, so that the final channel contains as much valid information as possible while ensuring the reliability of the final channel.

[0047] Furthermore, in one embodiment, ,in, 、 are the minimum and maximum delays of the direct wave and its multipath signal received in the underwater multipath channel, respectively. s is the sampling rate of the received signal.

[0048] Through this embodiment, the length of the target segment signal can be reasonably set.

[0049] Furthermore, in one embodiment, solving the estimated channel corresponding to the target segmented signal using a basis pursuit algorithm includes: Will , z and u are initialized to N w ×1 zero vector, initializing the number of iterations to zero; Increase the number of iterations by one and update , z and u: , , , Among them, A is the dictionary matrix, I is N w ×N w The identity matrix, is the target segment signal, represents the conjugate transpose of the matrix, ρ is the penalty coefficient, λ is the regularization coefficient, i=1,2,…, N w ; If the number of iterations is less than the upper limit of iterations, and , then return to execute the above and increase the number of iterations by one, update , z and u, otherwise stop the iteration and set the current As the estimated channel corresponding to the target segment signal, represents the 2-norm, and e2 is the second threshold.

[0050] Optionally, the upper limit of the number of iterations is 1000, and the second threshold is 10 -4 .

[0051] Furthermore, in one embodiment, reconstructing the direct wave and its multipath signal based on the transmitted signal and the final channel includes: Pad the transmitted signal and the final channel with zeros to obtain the first zero-padding result and the second zero-padding result: , , in, is the first zero-filling result, is the second zero-filling result, s is the transmitted signal, For the final channel, represents the matrix conjugate transpose, N y is the number of sampling points of the received signal, N s is the number of sampling points of the transmitted signal, N start N is the serial number of the first sampling point of the target segment signal in the received signal. end is the sequence number of the last sampling point of the target segment signal in the received signal; Perform linear convolution on the first zero-padding result and the second zero-padding result to obtain the convolution result: , in, is the convolution result, represents linear convolution; Extract the direct wave and its multipath signals from the convolution result: , in, It is a direct wave and its multipath signal.

[0052] A simulation test was conducted to verify the effect of the present application, and the simulation parameters were set as follows: the pulse width of the transmitted signal was 8s, the transmission period was 10s, the signal center frequency was 5kHz, the sampling rate of the transmitted signal and the received signal was 30kHz, the background noise was Gaussian white noise, the signal-to-interference ratio of the target echo to the direct wave was 60dB, the signal-to-noise ratio of the target echo to the noise was 20dB, the target speed was 20kn, the number of multipath channels of the direct wave was 10, the length of the sliding window was 4500, the sliding step size was 2250, the upper limit of the number of iterations was 1000, the first threshold was 0.8, and the second threshold was 10 -4 .

[0053] Figure 2 The figure shows the comparison results of the real channel and the final channel in the simulation experiment; Figure 3 shows the time-frequency diagram of the received signal in the simulation experiment; Figure 4 shows the time-frequency diagram of the inhibition results in the simulation experiment; Figure 5 The Doppler velocity diagram of the received signal, target echo and background noise in the simulation experiment is shown; Figure 6 The suppression results, target echo and background noise Doppler velocity diagrams in the simulation experiment are shown.

[0054] from Figure 2It can be seen that the final channel calculated by this application is highly consistent with the real channel. Figure 3 It can be seen that due to the interference of direct waves, it is difficult to see the target echo signal from the received signal. Figure 4 It can be seen that after the direct wave is suppressed by this application, the target echo signal is clearly visible in the suppression result. Figure 5 、 Figure 6 It can be seen that after the direct wave is suppressed by the present application, the side lobes of the direct wave are reduced to the noise background level, and the target echo is clearly visible.

[0055] In a second aspect, an embodiment of the present application also provides a continuous wave sonar direct wave suppression device.

[0056] Figure 7 A schematic diagram of the functional modules of a continuous wave sonar direct wave suppression device in one embodiment of the present application is shown.

[0057] Reference Figure 7 In one embodiment, the continuous wave sonar direct wave suppression device includes: The interception module 10 is used to intercept a new target segment signal from the received signal, wherein the target segment signal is composed of N consecutive w Sampling points The solution module 20 is used to solve the estimated channel corresponding to the target segment signal by using the basis pursuit algorithm, wherein the dictionary matrix of the basis pursuit algorithm is N w ×N w The Toeplitz matrix, the first column is the 1st to Nth column of the transmitted signal w sampling points, the 2nd to Nth sampling points in the first row w elements are all zero; a judgment module 30, configured to determine the current estimated channel as the final channel if the current estimated channel satisfies a judgment condition, and otherwise return to executing the step of intercepting a new target segmented signal from the received signal, wherein the judgment condition includes: a maximum element value in the estimated channel is greater than a first threshold; A reconstruction module 40 is used to reconstruct the direct wave and its multipath signal according to the transmitted signal and the final channel; The elimination module 50 is used to subtract the direct wave and its multipath signals from the received signal to obtain a suppression result.

[0058] Furthermore, in one embodiment, the interception module 10 is used to intercept the target segment signal corresponding to the sliding window from the received signal, wherein the size of the sliding window is N w The initial target segment signal is the 1st to Nth segment of the received signal. w sampling points; The judgment module 30 is used to move the sliding window backward N stepsampling points, and returns the target segmented signal corresponding to the sliding window intercepted from the received signal, wherein N step <N w .

[0059] Furthermore, in one embodiment, the judgment condition further includes: the sequence number of the maximum value element in the estimated channel is less than or equal to N step .

[0060] Furthermore, in one embodiment, the first threshold is set based on the relationship between the amplitudes of the transmitted signal and the received signal.

[0061] Furthermore, in one embodiment, ,in, 、 are the minimum and maximum delays of the direct wave and its multipath signal received in the underwater multipath channel, respectively. s is the sampling rate of the received signal.

[0062] Furthermore, in one embodiment, the solution module 20 is configured to: Will , z and u are initialized to N w ×1 zero vector, initializing the number of iterations to zero; Increase the number of iterations by one and update , z and u: , , , Among them, A is the dictionary matrix, I is N w ×N w The identity matrix, is the target segment signal, represents the conjugate transpose of the matrix, ρ is the penalty coefficient, λ is the regularization coefficient, i=1,2,…, N w ; If the number of iterations is less than the upper limit of iterations, and , then return to execute the above and increase the number of iterations by one, update , z and u, otherwise stop the iteration and set the current As the estimated channel corresponding to the target segment signal, represents the 2-norm, and e2 is the second threshold.

[0063] Furthermore, in one embodiment, the reconstruction module 40 is configured to: Pad the transmitted signal and the final channel with zeros to obtain the first zero-padding result and the second zero-padding result: , , in, is the first zero-filling result, is the second zero-filling result, s is the transmitted signal, For the final channel, represents the matrix conjugate transpose, N y is the number of sampling points of the received signal, N s is the number of sampling points of the transmitted signal, N start N is the serial number of the first sampling point of the target segment signal in the received signal. end is the sequence number of the last sampling point of the target segment signal in the received signal; Perform linear convolution on the first zero-padding result and the second zero-padding result to obtain the convolution result: , in, is the convolution result, represents linear convolution; Extract the direct wave and its multipath signals from the convolution result: , in, It is a direct wave and its multipath signal.

[0064] Among them, the functional implementation of each module in the above-mentioned continuous wave sonar direct wave suppression device corresponds to the various steps in the above-mentioned continuous wave sonar direct wave suppression method embodiment, and their functions and implementation processes are no longer repeated here.

[0065] In a third aspect, an embodiment of the present application provides a continuous wave sonar direct wave suppression device, which can be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0066] Figure 8 A schematic diagram of the hardware structure of the continuous wave sonar direct wave suppression device involved in the embodiment of the present application is shown.

[0067] Reference Figure 8 In an embodiment of the present application, a continuous wave sonar direct wave suppression device may include a processor, a memory, a communication interface, and a communication bus.

[0068] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0069] Communication interfaces include input / output (I / O), physical, and logical interfaces, which interconnect components within the CW sonar direct wave suppression device and other devices (such as other computing devices or user devices). Physical interfaces can be Ethernet, fiber, or ATM; user devices can include displays and keyboards.

[0070] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0071] The processor may be a general-purpose processor that can invoke a continuous wave sonar direct wave suppression program stored in a memory and execute the continuous wave sonar direct wave suppression method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the continuous wave sonar direct wave suppression program is invoked can be referenced from the various embodiments of the continuous wave sonar direct wave suppression method of the present application and will not be further described here.

[0072] Those skilled in the art will understand that Figure 8 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0073] In a fourth aspect, an embodiment of the present application also provides a storage medium.

[0074] The storage medium of the present application stores a continuous wave sonar direct wave suppression program, wherein when the continuous wave sonar direct wave suppression program is executed by the processor, the steps of the continuous wave sonar direct wave suppression method as described above are implemented.

[0075] Among them, the method implemented when the continuous wave sonar direct wave suppression program is executed can refer to the various embodiments of the continuous wave sonar direct wave suppression method of this application, and will not be repeated here.

[0076] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0077] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0078] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0079] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0080] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0081] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, or the part that contributes to the existing technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of this application.

[0082] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for suppressing direct waves of continuous wave sonar, characterized in that: The continuous wave sonar direct wave suppression method comprises: A new target segment signal is intercepted from the received signal, wherein the target segment signal is composed of N consecutive segments in the received signal. w Sampling points The estimated channel corresponding to the target segment signal is solved by the basis pursuit algorithm, where the dictionary matrix of the basis pursuit algorithm is N w ×N w The Toeplitz matrix, the first column is the 1st to Nth column of the transmitted signal w sampling points, the 2nd to Nth sampling points in the first row w elements are all zero; If the current estimated channel meets the judgment condition, the current estimated channel is determined as the final channel, otherwise the process returns to executing the method of intercepting a new target segmented signal from the received signal, wherein the judgment condition includes: the maximum element value in the estimated channel is greater than the first threshold; Reconstruct the direct wave and its multipath signals based on the transmitted signal and the final channel; The suppression result is obtained by subtracting the direct wave and its multipath signals from the received signal.

2. The method for suppressing direct waves of continuous wave sonar according to claim 1, wherein: The step of intercepting a new target segmented signal from the received signal comprises: The target segment signal corresponding to the sliding window is intercepted from the received signal, where the size of the sliding window is N w The initial target segment signal is the 1st to Nth segment of the received signal. w sampling points; The returning step of intercepting a new target segmented signal from the received signal includes: Move the sliding window backward N step sampling points, and returns the target segmented signal corresponding to the sliding window intercepted from the received signal, wherein N step <N w .

3. The method for suppressing direct waves of continuous wave sonar according to claim 2, characterized in that: The judgment condition also includes: the sequence number of the maximum value element in the estimated channel is less than or equal to N step .

4. The method for suppressing direct waves of continuous wave sonar according to claim 1, wherein: The first threshold is set based on the relationship between the amplitudes of the transmitted signal and the received signal.

5. The method for suppressing direct waves of continuous wave sonar according to claim 1, wherein: ,in, 、 are the minimum and maximum delays of the direct wave and its multipath signal received in the underwater multipath channel, respectively. s is the sampling rate of the received signal.

6. The method for suppressing direct waves of continuous wave sonar according to claim 1, wherein: Solving the estimated channel corresponding to the target segmented signal by a basis pursuit algorithm includes: Will , z and u are initialized to N w ×1 zero vector, initializing the number of iterations to zero; Increase the number of iterations by one and update , z and u: ， ， ， Among them, A is the dictionary matrix, I is N w ×N w The identity matrix, is the target segment signal, represents the conjugate transpose of the matrix, ρ is the penalty coefficient, λ is the regularization coefficient, i=1,2,…, N w ; If the number of iterations is less than the upper limit of iterations, and , then return to execute the above and increase the number of iterations by one, update , z and u, otherwise stop the iteration and set the current As the estimated channel corresponding to the target segment signal, represents the 2-norm, and e2 is the second threshold.

7. The method for suppressing direct waves of continuous wave sonar according to claim 1, wherein: The reconstructing the direct wave and its multipath signal according to the transmitted signal and the final channel includes: Pad the transmitted signal and the final channel with zeros to obtain the first zero-padding result and the second zero-padding result: ， ， in, is the first zero-filling result, is the second zero-filling result, s is the transmitted signal, For the final channel, represents the matrix conjugate transpose, N y is the number of sampling points of the received signal, N s is the number of sampling points of the transmitted signal, N start N is the serial number of the first sampling point of the target segment signal in the received signal. end is the sequence number of the last sampling point of the target segment signal in the received signal; Perform linear convolution on the first zero-padding result and the second zero-padding result to obtain the convolution result: ， in, is the convolution result, represents linear convolution; Extract the direct wave and its multipath signals from the convolution result: ， in, It is a direct wave and its multipath signal.

8. A continuous wave sonar direct wave suppression device, characterized in that: The continuous wave sonar direct wave suppression device comprises: The interception module is used to intercept a new target segment signal from the received signal, wherein the target segment signal is composed of N consecutive w Sampling points The solution module is used to solve the estimated channel corresponding to the target segment signal through the basis pursuit algorithm, where the dictionary matrix of the basis pursuit algorithm is N w ×N w The Toeplitz matrix, the first column is the 1st to Nth column of the transmitted signal w sampling points, the 2nd to Nth sampling points in the first row w elements are all zero; a judgment module, configured to determine the current estimated channel as the final channel if the current estimated channel satisfies a judgment condition, and otherwise return to executing the step of intercepting a new target segmented signal from the received signal, wherein the judgment condition includes: a maximum element value in the estimated channel is greater than a first threshold; A reconstruction module, used for reconstructing the direct wave and its multipath signals according to the transmitted signal and the final channel; The elimination module is used to subtract the direct wave and its multipath signals from the received signal to obtain a suppression result.

9. A continuous wave sonar direct wave suppression device, characterized in that: The continuous wave sonar direct wave suppression device includes a processor, a memory, and a continuous wave sonar direct wave suppression program stored in the memory and executable by the processor, wherein when the continuous wave sonar direct wave suppression program is executed by the processor, the steps of the continuous wave sonar direct wave suppression method according to any one of claims 1 to 7 are implemented.

10. A storage medium, characterized in that: The storage medium stores a continuous wave sonar direct wave suppression program, wherein when the continuous wave sonar direct wave suppression program is executed by the processor, the steps of the continuous wave sonar direct wave suppression method according to any one of claims 1 to 7 are implemented.

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