Shallow sea broadband sound source three-dimensional positioning method and system using double-vector hydrophone

Abstract

The invention provides a shallow sea sound source three-dimensional positioning method and system based on double vector hydrophones, and the method comprises the steps: laying at least two vector hydrophones in a designated sea area, and recording a broadband signal radiated by a sound source; respectively calculating the orientations of a broadband sound source relative to the two vector hydrophones according to measurement signals of the vector hydrophones, and determining the GPS position of the sound source and the orientation and distance of the sound source relative to the vector hydrophones according to the intersection point of the two orientations; carrying out modal separation on the vector hydrophone measurement signal to obtain each order of modal; and finally, calculating the energy of each order of modality to obtain the energy ratio of different modalities, and determining the depth of the sound source by matching the energy ratio of different modalities obtained by experimental measurement data with the energy ratio calculated by the sound field model. According to the method, three-dimensional estimation of sound source orientation, distance and depth can be realized only by arranging two vector hydrophones at a certain horizontal distance, and the system is simple and easy to operate; data analysis and processing are simple, and massive sound field calculation is not needed.

Description

Technical Field

[0001] This application belongs to the fields of underwater acoustic engineering, marine engineering, and sonar technology, and specifically relates to a method and system for three-dimensional localization of shallow sea broadband sound sources using a dual-vector hydrophone. Background Technology

[0002] Sound source localization has always been a hot topic in underwater acoustics research. In shallow sea environments, numerous sound source localization methods have been proposed based on full sound field information or sound field characteristic physical quantities and combined with signal processing techniques, such as sound source localization methods based on matched field processing technology, sound source localization methods based on sound field interference structures, and sound source localization methods based on modal separation and dispersion characteristics.

[0003] The sound source localization method based on matched field processing technology cross-correlates the actual measured underwater acoustic signal with the data calculated by the sound field model, and estimates the sound source distance and depth based on the resulting fuzzy surface. Traditional matched field localization methods have poor resolution, require increasing the array aperture to improve localization accuracy, are extremely sensitive to environmental parameter mismatch, and involve a large amount of sound field computation when calculating the copy field.

[0004] For a sound source localization method based on acoustic field interference structure, see the reference ("Robust passive rangeestimation using the waveguide invariant", published in J.Acosut.Soc.Am., Vol.127, No.5, starting page 2780, May 2010). This method achieves sound source localization based on the relationship between the slope of the interference fringes and the distance and depth of the sound source.

[0005] The sound source localization method based on modal separation and dispersion characteristics can be found in the reference (“A waveguide-invariant-based warping operator and its application to passive source rangeestimation”, published in J. Comput. Acoust., Vol. 23, No. 1, January 2015, starting page 1550003-1). This method mainly separates different modes through time-frequency analysis and warping transform, and estimates the sound source distance using the arrival time difference of different modes.

[0006] Sound source localization methods based on acoustic field interference structures and modal separation and dispersion characteristics mainly estimate the distance to the sound source. A few studies estimate or distinguish the depth of the sound source (distinguishing between surface and underwater sound sources), and it is difficult to estimate the direction of the sound source using a small amount of hydrophone measurement data. Summary of the Invention

[0007] The purpose of this application is to overcome the shortcomings of existing sound source localization methods, which are unable to achieve three-dimensional localization of sound source orientation, distance, and depth using a small amount of hydrophone measurement data.

[0008] To achieve the above objectives, this application proposes a three-dimensional localization method for shallow-sea broadband sound sources using a dual-vector hydrophone, comprising:

[0009] Step 1: Deploy at least two vector hydrophones in the designated sea area to record the broadband signal radiated by the sound source;

[0010] Step 2: Calculate the azimuth of the broadband sound source relative to the two vector hydrophones. Determine the GPS position of the sound source from the intersection of these two azimuths, and further determine the azimuth and distance of the sound source relative to the vector hydrophones.

[0011] Step 3: Perform mode separation on the vector hydrophone measurement signal to obtain each mode;

[0012] Step 4: Determine the sound source depth by experimentally measuring the modal energy ratios of the signal and comparing them with the modal energy ratios calculated from the sound field model.

[0013] As an improvement to the above method, step 1 includes:

[0014] The distance between the vector hydrophone and the sound source is greater than 1km and less than 60km, and the sound source frequency is less than 300Hz.

[0015] As an improvement to the above method, step 2 includes:

[0016] The azimuth of the sound source relative to the two vector hydrophones was determined using the average acoustic energy flow method, and the azimuth angles of the sound source were obtained as follows:

[0017]

[0018] Where α1 represents the azimuth angle of the sound source relative to the first vector hydrophone; α2 represents the azimuth angle of the sound source relative to the second vector hydrophone; p1(r,z,t) represents the sound pressure signal measured by the first vector hydrophone; v x1 (r,z,t) represents the x-component of the particle velocity measured by the first vector hydrophone; v y1 (r,z,t) represents the y-component of the particle velocity measured by the first vector hydrophone; p2(r,z,t) represents the sound pressure signal measured by the second vector hydrophone; v x2 (r,z,t) represents the x-component of the particle velocity measured by the second vector hydrophone; v y2 (r,z,t) represents the y-component of the particle velocity measured by the second vector hydrophone; < > represents the average over time; r is the distance to the sound source, z is the receiving depth of the vector hydrophone; t is time;

[0019] The intersection of azimuth α1 and α2 is the location of the sound source. The GPS location of the sound source is determined on a two-dimensional plane, and the azimuth and distance of the sound source relative to the vector hydrophone are further determined.

[0020] As an improvement to the above method, step 2 further includes:

[0021] If the sound source is on the line connecting two vector hydrophones or on the extension of the line, add another vector hydrophone so that the positional relationship of the three vector hydrophones forms a triangle. Then, use the average sound energy flow method to determine the orientation of the sound source relative to the vector hydrophones, determine the two-dimensional geographic coordinates of the sound source, and further determine the orientation and distance of the sound source relative to the vector hydrophones.

[0022] As an improvement to the above method, the vector hydrophone measurement signal in step 3 is a sound pressure signal.

[0023] As an improvement to the above method, step 3 includes:

[0024] Warping transform was used to perform mode separation on the sound pressure signal to obtain each mode; time transform was then used. Where t' is the warping time, t0 is the time it takes for the sound source to reach the receiving vector hydrophone, and the sound pressure signal p(r,z,z) is... s ,t) becomes:

[0025]

[0026] Where r is the distance to the sound source, z is the receiving depth of the vector hydrophone, and z s Let y(r,z,z) represent the depth of the sound source, and t represent time. s ,t') and y n (r,z,z s ,t') represent the signal after the Warping transformation and each mode, respectively; N is the total number of modes; then y n (r,z,z s Performing an inverse Warping transform on t') yields the time-domain waveforms p for each mode. n (r,z,z s ,t).

[0027] As an improvement to the above method, step 4 includes:

[0028] Calculate the modes p of the sound pressure signal n (r,z,z s Energy E of t) n :

[0029]

[0030] Where r is the distance to the sound source, z is the receiving depth of the vector hydrophone, and z s The depth of the sound source is given by t, and time is given by [t1, t2], which represents the time range of the measured signal. N is the total number of modes. The energy ratio A between the m-th and n-th modes is given by [t1, t2]. m,n (z s ) is represented as:

[0031]

[0032] The cost function C is obtained from the energy ratio of the m-th and n-th modes. m,n (z') is represented as:

[0033] C m,n (z')=|A m,n (z')-A m,n (z s )|

[0034] Among them, A m,n (z') represents the energy ratio of the m-th and n-th modes when the sound source depth is z' calculated by the sound field model, and the depth corresponding to the minimum value of the cost function is the estimated sound source depth.

[0035] As an improvement to the above method, step 4 further includes:

[0036] The cost function is obtained by calculating the energy ratio of the Mth, M<=Nth and the nth, n≠Mth modes, and the average of these ratios is taken as the final cost function for estimating the sound source depth.

[0037] As an improvement to the above method, the vector hydrophone measurement signal in step 3 is either the horizontal particle velocity or the vertical particle velocity.

[0038] This application also provides a shallow-sea broadband sound source three-dimensional localization system using a dual-vector hydrophone, implemented based on the above method, the system comprising:

[0039] A broadband signal recording module is used to record broadband signals radiated by a sound source using at least two vector hydrophones deployed in a designated sea area.

[0040] The module for determining the location of the sound source and its orientation and distance relative to the vector hydrophones is used to calculate the orientation of the broadband sound source relative to the two vector hydrophones. The intersection of these two orientations determines the GPS location of the sound source, and further determines the orientation and distance of the sound source relative to the vector hydrophones.

[0041] The mode separation module is used to perform mode separation on the vector hydrophone measurement signal to obtain the various modes.

[0042] The sound source depth estimation module is used to determine the sound source depth by experimentally measuring the modal energy ratios of the signal and calculating the modal energy ratios of the signal from the sound field model.

[0043] Compared with existing technologies, the advantages of this application are:

[0044] 1. The method of the present invention uses the broadband signals received by two vector hydrophones to locate shallow sea sound sources, without the need for multiple hydrophones to form an array. The vector hydrophones can be placed on the bottom to receive signals, and the equipment deployment is relatively simple.

[0045] 2. The method of the present invention utilizes both scalar and vector information of the sound field, enabling three-dimensional localization of shallow sea sound sources with less spatial sampling data;

[0046] 3. Compared with the matched field localization method, the use of two vector hydrophones for sound source localization has the advantages of simple deployment, less spatial sampling, less computation, and can simultaneously estimate the azimuth, distance and depth of the sound source. Attached Figure Description

[0047] Figure 1 The diagram shows a flowchart of a three-dimensional localization method for shallow-sea broadband sound sources using a dual-vector hydrophone.

[0048] Figure 2 The diagram shows the placement of the vector hydrophone and the location of the sound source.

[0049] Figure 3(a) shows the measured sound speed profile in the marine experiment;

[0050] Figure 3(b) shows the measured signal waveform of the vector hydrophone in the marine experiment;

[0051] Figure 4(a) shows the azimuth angle of the sound source estimated using the measured signal from a vector hydrophone;

[0052] Figure 4(b) shows the geographic coordinates of the sound source on a two-dimensional plane estimated using the measured signal from a vector hydrophone.

[0053] Figure 5 The image shows the waveforms of each mode extracted from the measured signal of the vector hydrophone;

[0054] Figure 6 The figure shows the energy ratios of different modes obtained from the measured signals of a vector hydrophone;

[0055] Figure 7 The figure shows the sound source depth estimated by the cost function. Detailed Implementation

[0056] The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0057] This invention proposes a three-dimensional localization method and system for shallow-sea (depth less than 500m) sound sources based on dual-vector hydrophones. First, two vector hydrophones at suitable depths (far from the sea surface) are deployed in a designated sea area to record the broadband signal radiated by the sound source. The azimuth of the broadband sound source relative to the two vector hydrophones is calculated based on the measured signals. The intersection of these two azimuths determines the GPS position of the sound source, thus determining the azimuth and distance of the sound source relative to the vector hydrophones. Next, modal separation is performed on the recorded signals from the vector hydrophones to obtain each mode. Finally, the energy of each mode is calculated to obtain the energy ratio of different modes. The sound source depth is determined by matching the energy ratios obtained from experimental measurements with those calculated from the sound field model. This method requires only measurement data from two vector hydrophones to achieve three-dimensional estimation of the sound source's azimuth, distance, and depth. It eliminates the need for deploying a vertical array covering the entire sea depth, making the system simple, easy to operate, requiring minimal sound field calculations, and simplifying data analysis and processing.

[0058] Example 1

[0059] like Figure 1 As shown, the three-dimensional localization method for shallow sea sound sources based on dual-vector hydrophones includes:

[0060] Step 1: Deploy at least two vector hydrophones in the designated sea area and record the broadband signals emitted by the broadband sound source.

[0061] At least two vector hydrophones should be deployed in the designated sea area, with a certain distance between them. To ensure the stability of the vector hydrophones during operation, they can be deployed on the seabed or a seabed seismometer can be used to receive the signal radiated by the broadband sound source. When deploying the vector hydrophones, the actual azimuth of each component should be known. The distance between the vector hydrophone and the sound source should be greater than 1 km and less than 60 km, and the sound source frequency should be less than 300 Hz. The experimental sea area can be approximated as a horizontally stable marine environment.

[0062] In addition, seawater sound velocity profiles can be obtained through temperature, salinity, and depth measuring instruments; and information such as seawater depth and topography can be obtained through multibeam systems or nautical charts.

[0063] Step 2: Calculate the azimuth of the broadband sound source relative to the two vector hydrophones. Determine the GPS position of the sound source from the intersection of these two azimuths, and further determine the azimuth and distance of the sound source relative to the vector hydrophones.

[0064] The average sound energy flow method is used to calculate the azimuth of the broadband sound source relative to two vector hydrophones from the measured sound pressure and the horizontal components (x and y components) of the particle velocity. The intersection of these two azimuths determines the GPS position of the sound source. Then, the azimuth and distance of the sound source relative to the vector hydrophones are determined by the GPS position of the sound source and the GPS position of the vector hydrophones.

[0065] Regarding the x and y directions of a vector hydrophone—a vector hydrophone can measure the components of sound pressure signals and particle velocities in each direction (x, y, z) in a three-dimensional rectangular coordinate system. These components are measured by independent sensors. The x and y components are the horizontal particle velocity components, and the z component is the vertical particle velocity component.

[0066] Step 2 specifically includes:

[0067] The sound pressure signal and particle velocity x and y components recorded by the vector hydrophone during the observation time t1 < t < t2 are p(r,z,t) and v(t,z,t), respectively. x (r,z,t) and v y (r,z,t), where r represents the horizontal distance between the vector hydrophone and the sound source, and z represents the depth of the vector hydrophone at the recording time.

[0068] Given p(r,z,t) and v x (r,z,t) and v y From (r,z,t), we can obtain the average acoustic intensity flow of the vector hydrophone in the x and y directions:

[0069] I x (r,z)= <p(r,z,t)v x (r,z,t)>

[0070] I y (r,z)= <p(r,z,t)v y (r,z,t)>

[0071] Where < > represents the average over time.

[0072] by I x (r,z) and I y (r,z) yields the azimuth angle of the sound source relative to the vector hydrophone, i.e.:

[0073]

[0074] Let the azimuth angles of the sound source obtained from the measurement data of two vector hydrophones be α1 and α2, respectively. Plot these two azimuth angles on a two-dimensional plan view of the vector hydrophone placement locations. The intersection of these two azimuth angles is the position of the sound source on the two-dimensional plan view. If the sound source is on the line connecting the two vector hydrophones or on the extension of that line, a third vector hydrophone can be added, making the positional relationship of the three vector hydrophones form a triangle. Repeating the above analysis process, the two-dimensional geographic coordinates of the sound source can be determined, and further, the azimuth and distance of the sound source relative to the vector hydrophones can be determined.

[0075] Step 3: Perform mode separation on the vector hydrophone recorded signal to obtain each mode;

[0076] To obtain a high signal-to-noise ratio, signals recorded by vector hydrophones located close to the sound source were selected. Mode separation was performed using time-domain warping transform to obtain the waveforms of each mode. Specifically, this included:

[0077] The sound pressure signal received by a vector hydrophone can be represented as a superposition of multiple modes:

[0078]

[0079] Where r is the distance to the sound source, z is the receiving depth of the vector hydrophone, and z s Let f be the sound source depth, f be the frequency, S(f) be the sound source spectrum, [f1,f2] be the frequency range of the signal being analyzed, and p(r,z,z) be the signal source frequency. s (t) represents the waveform of the sound pressure signal received by the vector hydrophone, p n (r,z,z s ,t) is the waveform of the nth mode, and N is the total number of modes.

[0080] Using time transformation:

[0081]

[0082] Where t' is called the warping time, and t0 is the time it takes for the sound source to reach the receiving vector hydrophone.

[0083] Let p(r,z,z) s ,t) becomes:

[0084]

[0085] Where h'(t') = t' / h(t') is used to ensure energy conservation before and after the transformation. y(r,z,z) s ,t') and y n (r,z,z s ,t') represent the signal after the Warping transformation and the various modes, respectively, y n (r,z,z s The modes ,t') are separated at the warping frequency. Filtering can separate the individual modes, and then the y... n (r,z,z s Performing the inverse Warping transform on t') yields the time-domain waveforms p for each mode. n (r,z,z s ,t).

[0086] Step 4: Determine the sound source depth by comparing the modal energy ratios of the experimentally measured signal with those calculated from the sound field model.

[0087] Based on the modal time-domain data p obtained in step 3n (r,z,z s ,t) calculate the signal energy, i.e.

[0088]

[0089] The energy ratio between the m-th and n-th modes is:

[0090]

[0091] First, the following cost function is constructed to estimate the depth of the sound source:

[0092] C m,n (z')=|A m,n (z')-A m,n (z s )|

[0093] Among them, A m,n (z') represents the energy ratio of the m-th and n-th modes when the sound source depth is z' calculated by the sound field model, and the depth corresponding to the minimum value of the cost function is the estimated sound source depth.

[0094] Then, taking into account the cost function C obtained from the energy ratios of different modes, m,n (z'), if we use the energy ratio of the Nth (highest) mode to all modes of lower order, i.e., C N,1 (z'), C N,2 (z'), ..., C N,N-1 (z'), their mean is taken as the cost function for the final estimation of the sound source depth, i.e.

[0095]

[0096] The method of the present invention will be verified below using actual data as an example:

[0097] Step 1: Deploy at least two vector hydrophones in the designated sea area and record the broadband signals emitted by the broadband sound source.

[0098] like Figure 2 As shown, this embodiment uses two vector hydrophones as an example. First, two vector hydrophones are deployed in a designated sea area, with the line connecting the two vector hydrophones forming a certain angle with the line connecting the sound source and either of the vector hydrophones. To ensure the stability of the vector hydrophones during operation, a base is placed on the bottom of the vector hydrophones. The distance of the sound source signal from the vector hydrophone is greater than 1km and less than 60km, and the sound source frequency is less than 300Hz.

[0099] In this embodiment, the experimental sea area is approximately 92.2m deep. A vector hydrophone (an underwater seismograph was used in the experiment) receives broadband sound source signals at its base. The sound source is approximately 15m deep and transmits a signal every minute. The distance between the two vector hydrophones is approximately 50km, and the sound source is approximately 7.11km away from vector hydrophone 1.

[0100] Step 2: Calculate the orientation of the broadband sound source relative to the two vector hydrophones. Determine the GPS location of the sound source from the intersection of these two orientations, and further determine the orientation and distance of the sound source relative to the vector hydrophones.

[0101] Figures 3(a) and 3(b) show the measured sound velocity profile and the measured signal waveform of the vector hydrophone in this embodiment. In this embodiment, the sound pressure and particle velocity components in the x and y directions measured by the two vector hydrophones at time [t1,t2] are p1(r,z,t) and v1(r,z,t), respectively. x1 (r,z,t) and p2(r,z,t), v x2 (r,z,t),v y2 From (r,z,t), we can obtain the average acoustic intensity flow in the x and y directions of the two vector hydrophones:

[0102] I x1 (r,z)= <p1(r,z,t)v x1 (r,z,t)

[0103] I y1 (r,z)= <p1(r,z,t)v y1 (r,z,t)

[0104] I x2 (r,z)= <p2(r,z,t)v x2 (r,z,t)

[0105] I y2 (r,z)= <p2(r,z,t)v y2 (r,z,t)

[0106] Where < > represents the average over time; t is time.

[0107] byI x1 (r,z), I y1 (r,z) and I x2 (r,z), I y2 (r,z) yields the azimuth angles of the sound source relative to the two vector hydrophones as follows:

[0108]

[0109] Where α1 represents the azimuth angle of the sound source relative to the first vector hydrophone; α2 represents the azimuth angle of the sound source relative to the second vector hydrophone; r is the distance to the sound source; and z is the receiving depth of the vector hydrophone.

[0110] The relative positions of the two vector hydrophones and the orientation of the sound source relative to the two vector hydrophones are plotted on a two-dimensional planar diagram. The intersection of these two orientations is the position of the sound source on the two-dimensional planar diagram. From this sound source position, the orientation and distance of the sound source relative to the vector hydrophones can be determined, as shown in Figures 4(a) and 4(b). The frequency used in the figures is 5-60Hz. It should be noted that the actual orientations of the x and y components of the particle velocity of each vector hydrophone deployed in the experiment are unknown in this embodiment. The x and y directions of the two vector hydrophones in Figure 4(b) are determined by the explosion sound source signal with known orientation.

[0111] Step 3: Perform mode separation on the vector hydrophone recorded signal to obtain each mode.

[0112] Narrowband filtering was applied to the sound pressure signal measured by one of the vector hydrophones. In this embodiment, the signal measured by the vector hydrophone closer to the sound source was selected, and the filtering frequency range was 85-100Hz. The signal measured in this frequency range contained 4th-order modes, and this signal was denoted as p(r,z,z). s ,t).

[0113] Using time transformation:

[0114]

[0115] Where t0 is the time it takes for the sound source to reach the receiving vector hydrophone.

[0116] Let p(r,z,z) s ,t) becomes:

[0117]

[0118] Among them, h'(t')=t' / h(t'). y(r,z,z s ,t') and y n (r,z,z s ,t') represent the signal after the Warping transformation and each mode, respectively. Then, for y n (r,z,z s Performing the inverse Warping transform on t') yields the time-domain waveforms p for each mode. n (r,z,z s ,t).

[0119] In this embodiment, the obtained fourth-order modes are denoted as p1(r,z,z). s,t)p2(r,z,z s ,t), p3(r,z,z) s ,t), p4(r,z,z) s ,t), its waveform is as follows Figure 5 As shown.

[0120] Step 4: Determine the sound source depth by matching the modal energy ratios of the measured signal with those calculated from the sound field model.

[0121] Calculate the energy of each mode, i.e.:

[0122]

[0123] Then the energy ratio A between the fourth and second modes is obtained. 4,2 The energy ratio A between the fourth and third modes 4,3 In this embodiment, data from 30 sets of air gun signals are analyzed, A 4,2 and A 4,3 like Figure 6 As shown. Because the first-order mode has low energy, it is prone to causing large errors in sound source estimation. Therefore, the energy ratio of the first-order mode to other modes was not used.

[0124] By A 4,2 and A 4,3 We obtained the following respectively:

[0125] C 4,2 (z')=|A 4,2 (z')-A 4,2 |

[0126] C 4,3 (z')=|A 4,3 (z')-A 4,3 |

[0127] Among them, A 4,2 (z') and A 4,3 (z') represents the energy ratios of the 4th and 2nd modes, and the 4th and 3rd modes, respectively, when the sound source depth is z', calculated by the model (KRAKEN).

[0128] By C 4,2 (z') and C 4,3 The mean of (z') is used as the cost function for the final estimation of the sound source depth, i.e.:

[0129]

[0130] The depth corresponding to the minimum value of the cost function is the estimated sound source depth. In this embodiment, the curve of the cost function C(z') as a function of depth is shown below. Figure 7As shown, the estimated sound source depth is 17.8m, which is consistent with the actual sound source depth (approximately 15m).

[0131] In this embodiment, the sound pressure signal is modally separated to obtain each mode, and the sound source depth is determined by comparing the energy ratio of each mode with that calculated from the sound field model. In other embodiments, modal separation can also be performed on the horizontal or vertical particle velocity to obtain each mode, and the sound source depth can be determined by comparing the energy ratio of each mode with that calculated from the sound field model.

[0132] Example 2

[0133] This application also provides a shallow-sea broadband sound source three-dimensional localization system using a dual-vector hydrophone, implemented based on the above method, the system comprising:

[0134] A broadband signal recording module is used to record broadband signals radiated by a sound source using at least two vector hydrophones deployed in a designated sea area.

[0135] The module for determining the location of the sound source and its orientation and distance relative to the vector hydrophones is used to calculate the orientation of the broadband sound source relative to the two vector hydrophones. The intersection of these two orientations determines the GPS location of the sound source, and further determines the orientation and distance of the sound source relative to the vector hydrophones.

[0136] The mode separation module is used to perform mode separation on the vector hydrophone measurement signal to obtain the various modes.

[0137] The sound source depth estimation module is used to determine the sound source depth by experimentally measuring the modal energy ratios of the signal and calculating the modal energy ratios of the signal from the sound field model.

[0138] This application may also provide a computer device, including: at least one processor, memory, at least one network interface, and a user interface. The various components in this device are coupled together via a bus system. It is understood that the bus system is used to implement communication between these components. In addition to a data bus, the bus system also includes a power bus, a control bus, and a status signal bus.

[0139] The user interface can include a display, keyboard, or clicking device. Examples include a mouse, trackball, touchpad, or touchscreen.

[0140] It is understood that the memory in the embodiments disclosed in this application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory may be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate Synchronous DRAM (DDRSDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memories described herein are intended to include, but are not limited to, these and any other suitable types of memory.

[0141] In some implementations, the memory stores elements such as executable modules or data structures, or subsets thereof, or extended sets thereof: operating systems and applications.

[0142] The operating system includes various system programs, such as the framework layer, core library layer, and driver layer, used to implement various basic business functions and handle hardware-based tasks. The application programs include various applications, such as media players and browsers, used to implement various application functions. Programs implementing the methods of the embodiments of this disclosure can be included in the application programs.

[0143] In the above embodiments, the processor can also invoke programs or instructions stored in memory, specifically programs or instructions stored in an application program, for the following purposes:

[0144] Follow the steps described above.

[0145] The above methods can be applied to or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above methods can be completed by integrated logic circuits in the processor's hardware or by software instructions. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the disclosed methods, steps, and logic block diagrams. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the disclosed methods can be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above methods.

[0146] It is understood that the embodiments described in this application can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in this application, or combinations thereof.

[0147] For software implementation, the technology of this application can be implemented by executing the functional modules (e.g., procedures, functions, etc.) of this application. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or externally.

[0148] This application may also provide a non-volatile storage medium for storing a computer program. When the computer program is executed by a processor, it can implement the steps in the above method embodiments.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application, and should all be covered within the scope of the claims of this application.

Claims

1. A method for three-dimensional localization of a broadband sound source in shallow sea using a dual-vector hydrophone, comprising: Step 1: Deploy at least two vector hydrophones in the designated sea area to record the broadband signal radiated by the sound source; Step 2: Calculate the azimuth of the broadband sound source relative to the two vector hydrophones. Determine the GPS position of the sound source from the intersection of these two azimuths, and further determine the azimuth and distance of the sound source relative to the vector hydrophones. Step 3: Perform mode separation on the vector hydrophone measurement signal to obtain each mode; Step 4: Determine the sound source depth by experimentally measuring the modal energy ratios of the signal and comparing them with the modal energy ratios calculated from the sound field model.

2. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 1, characterized in that, Step 1 includes: The distance between the vector hydrophone and the sound source is greater than 1km and less than 60km, and the sound source frequency is less than 300Hz.

3. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 1, characterized in that, Step 2 includes: The azimuth of the sound source relative to the two vector hydrophones was determined using the average acoustic energy flow method, and the azimuth angles of the sound source were obtained as follows: Where α1 represents the azimuth angle of the sound source relative to the first vector hydrophone; α2 represents the azimuth angle of the sound source relative to the second vector hydrophone; p1(r,z,t) represents the sound pressure signal measured by the first vector hydrophone; v x1 (r,z,t) represents the x-component of the particle velocity measured by the first vector hydrophone; v y1 (r,z,t) represents the y-component of the particle velocity measured by the first vector hydrophone; p2(r,z,t) represents the sound pressure signal measured by the second vector hydrophone; v x2 (r,z,t) represents the x-component of the particle velocity measured by the second vector hydrophone; v y2 (r,z,t) represents the y-component of the particle velocity measured by the second vector hydrophone; < > represents the average over time; r is the distance to the sound source, z is the receiving depth of the vector hydrophone; t is time; The intersection of azimuth α1 and α2 is the location of the sound source. The GPS location of the sound source is determined on a two-dimensional plane, and the azimuth and distance of the sound source relative to the vector hydrophone are further determined.

4. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 3, characterized in that, Step 2 also includes: If the sound source is on the line connecting two vector hydrophones or on the extension of the line, add another vector hydrophone so that the positional relationship of the three vector hydrophones forms a triangle. Then, use the average sound energy flow method to determine the orientation of the sound source relative to the vector hydrophones, determine the two-dimensional geographic coordinates of the sound source, and further determine the orientation and distance of the sound source relative to the vector hydrophones.

5. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 1, characterized in that, In step 3, the vector hydrophone measurement signal is a sound pressure signal.

6. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 5, characterized in that, Step 3 includes: Warping transform was used to perform mode separation on the sound pressure signal to obtain each mode; time transform was then used. Where t' is the warping time, t0 is the time it takes for the sound source to reach the receiving vector hydrophone, and the sound pressure signal p(r,z,z) is... s ,t) becomes: Where r is the distance to the sound source, z is the receiving depth of the vector hydrophone, and z s Let y(r,z,z) represent the depth of the sound source, and t represent time. s ,t') and y n (r,z,z s ,t') represent the signal after the Warping transformation and each mode, respectively; N is the total number of modes; then y n (r,z,z s Performing an inverse Warping transform on t') yields the time-domain waveforms p for each mode. n (r,z,z s ,t).

7. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 1, characterized in that, Step 6 includes: Calculate the modes p of the sound pressure signal n (r,z,z s Energy E of t) n : Where r is the distance to the sound source, z is the receiving depth of the vector hydrophone, and z s The depth of the sound source is given by t, and time is given by [t1, t2], which represents the time range of the measured signal. N is the total number of modes. The energy ratio between the m-th and n-th modes is A. m,n (z s ) is represented as: The cost function C is obtained from the energy ratio of the m-th and n-th modes. m,n (z') is represented as: C m,n (z')=|A m,n (z')-A m,n (from s )| Among them, A m,n (z') represents the energy ratio of the m-th and n-th modes when the sound source depth is z' calculated by the sound field model, and the depth corresponding to the minimum value of the cost function is the estimated sound source depth.

8. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 7, characterized in that, Step 4 also includes: The cost function is obtained by calculating the energy ratio of the Mth, M<=Nth and the nth, n≠Mth modes, and the average of these ratios is taken as the final cost function for estimating the sound source depth.

9. The shallow-sea broadband sound source three-dimensional localization method using a dual-vector hydrophone according to claim 1, characterized in that, In step 3, the vector hydrophone measures either the horizontal or vertical particle velocity.

10. A shallow-sea broadband sound source three-dimensional localization system utilizing a dual-vector hydrophone, implemented based on the method described in any one of claims 1-9, characterized in that, The system includes: A broadband signal recording module is used to record broadband signals radiated by a sound source using at least two vector hydrophones deployed in a designated sea area. The module for determining the location of the sound source and its orientation and distance relative to the vector hydrophones is used to calculate the orientation of the broadband sound source relative to the two vector hydrophones. The intersection of these two orientations determines the GPS location of the sound source, and further determines the orientation and distance of the sound source relative to the vector hydrophones. The mode separation module is used to perform mode separation on the vector hydrophone measurement signal to obtain the various modes. The sound source depth estimation module is used to determine the sound source depth by experimentally measuring the modal energy ratios of the signal and calculating the modal energy ratios of the signal from the sound field model.

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