A shallow water broadband sound source three-dimensional positioning method and system using a dual-vector hydrophone

Abstract

The application provides a shallow sea sound source three-dimensional positioning method and system based on a double vector hydrophone, and the method comprises the following steps: deploying at least two vector hydrophones in a specified sea area, and recording a broadband signal radiated by a sound source; calculating the azimuth of the broadband sound source relative to the two vector hydrophones according to the vector hydrophone measurement signals, determining the GPS position of the sound source from the intersection of the two azimuths, and determining the azimuth and distance of the sound source relative to the vector hydrophones; then performing modal separation on the vector hydrophone measurement signals to obtain each order mode; finally, calculating the energy of each order mode to obtain the energy ratio of different modes, and determining the depth of the sound source by matching the different mode energy ratios obtained from the experimental measurement data with the different mode energy ratios calculated from the sound field model. According to the method, the sound source azimuth, distance and depth can be three-dimensionally estimated by deploying two vector hydrophones at a certain horizontal distance, the system is simple and easy to operate, data analysis and processing are simple, and a large amount of sound field calculation is not required.

Description

TECHNICAL FIELD

[0001] The application belongs to the fields of underwater acoustic engineering, ocean engineering, sonar technology, and the like, and particularly relates to a shallow sea broadband sound source three-dimensional positioning method and system using a double-vector hydrophone. BACKGROUND

[0002] Sound source positioning has always been a hot issue in the study of underwater acoustics. In the shallow sea environment, based on the full sound field information or the sound field characteristic physical quantity and combined with the signal processing technology, a large number of sound source positioning methods have been proposed, such as the sound source positioning method based on the matched field processing technology, the sound source positioning method based on the sound field interference structure, the sound source positioning method based on the modal separation and dispersion characteristics, and the like.

[0003] The sound source positioning method based on the matched field processing technology carries out cross-correlation processing on the actual measured underwater acoustic signal and the data calculated by the sound field model, and realizes the estimation of the sound source distance and depth according to the obtained ambiguous surface. The traditional matched field positioning method has poor resolution, needs to increase the array aperture to improve the positioning accuracy, and is extremely sensitive to the mismatch of environmental parameters and has a large sound field calculation amount when calculating the copy field.

[0004] The sound source positioning method based on the sound field interference structure, as described in the reference (“Robust passive range estimation using the waveguide invariant”, published in J. Acosut. Soc. Am. in May 2010, Vol. 127, No. 5, starting page 2780), realizes the sound source positioning according to the relationship between the interference fringe slope and the sound source distance and depth.

[0005] The sound source positioning method based on the modal separation and dispersion characteristics, as described in the reference (“A waveguide-invariant-based warping operator and its application to passive source range estimation”, published in J. Comput. Acoust. in January 2015, Vol. 23, No. 1, starting page 1550003-1), mainly separates different modes through time-frequency analysis, Warping transformation and the like, and estimates the sound source distance by using the time difference of arrival of different modes.

[0006] The sound source positioning methods based on the sound field interference structure and the modal separation and dispersion characteristics mainly estimate the sound source distance, a few of the researches estimate or distinguish (distinguish the water surface and underwater sound source) the sound source depth, and it is difficult to estimate the sound source direction by using a small amount of hydrophone measurement data. SUMMARY

[0007] The present application aims to overcome the defects of the prior art that it is difficult to realize three-dimensional positioning of the sound source azimuth, distance and depth with a small amount of hydrophone measurement data.

[0008] To achieve the above object, the present application provides a shallow sea broadband sound source three-dimensional positioning method using double vector hydrophones, comprising:

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

[0010] Step 2: calculating the azimuth of the broadband sound source relative to the two vector hydrophones, determining the GPS position of the sound source from the intersection of the two azimuths, and further determining the azimuth and distance of the sound source relative to the vector hydrophones;

[0011] Step 3: modal separation of the vector hydrophone measurement signal to obtain each order modal;

[0012] Step 4: determining the depth of the sound source by comparing the experimental measurement signal of each order modal energy ratio with the calculated energy ratio of each order modal from the sound field model.

[0013] As an improvement of the above method, the step 1 comprises:

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

[0015] As an improvement of the above method, the step 2 comprises:

[0016] The average sound energy flow method is used to determine the azimuth of the sound source relative to the two vector hydrophones, and the azimuth angles of the sound source are respectively:

[0017]

[0018] Wherein, 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 of the sound source, z is the receiving depth of the vector hydrophone; t is the time;

[0019] The intersection of the two azimuths a1 and a2 is the sound source position, which determines the GPS position of the sound source in two-dimensional plane, and further determines the azimuth and distance of the sound source relative to the vector hydrophone.

[0020] As an improvement of the above method, the step 2 further comprises:

[0021] If the sound source is on the line or the extension of the line of the two vector hydrophones, an additional vector hydrophone is added to form a triangle with the three vector hydrophones, and then the average sound energy flow method is used to determine the azimuth of the sound source relative to the vector hydrophone, determine the two-dimensional geographical coordinates of the sound source, and further determine the azimuth and distance of the sound source relative to the vector hydrophone.

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

[0023] As an improvement of the above method, the step 3 comprises:

[0024] The sound pressure signal is subjected to modal separation by Warping transformation to obtain each order modal; time transformation wherein t' is the Warping time, t0 is the time when the sound source reaches the receiving vector hydrophone, and the sound pressure signal p(r, z, z s , t) becomes:

[0025]

[0026] wherein r is the distance of the sound source, z is the receiving depth of the vector hydrophone, z s is the depth of the sound source, and t is the time; y(r, z, z s , t') and y n (r, z, z s , t') are the signals and each order modal after Warping transformation, respectively; N is the total number of modes; then y n (r, z, z s , t') is subjected to Warping inverse transformation to obtain the time-domain waveform p n (r, z, z s , t) of each modal.

[0027] As an improvement of the above method, the step 4 comprises:

[0028] The energy E n of each order modal p s (r, z, z n , t) of the sound pressure signal is calculated:

[0029]

[0030] where r is the source distance, z is the receiving depth of the vector hydrophone, z s is the source depth, t is the time; [t1, t2] is the time range of the measured signal; N is the total mode number; the energy ratio A m,n (z s ) is represented as:

[0031]

[0032] The cost function C m,n (z') is represented as:

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

[0034] where A m,n (z') represents the energy ratio of the mth mode and the nth mode when the 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 source depth.

[0035] As an improvement of the above method, the step 4 further comprises:

[0036] The cost function obtained by calculating the energy ratio of the Mth mode, M<=N, and the nth mode, n≠M, is taken as the cost function of the final estimated source depth.

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

[0038] The application also provides a shallow sea wideband sound source three-dimensional positioning system using double vector hydrophones, which is realized based on the above method, and the system comprises:

[0039] A wideband signal recording module is used to record the wideband signal radiated by the sound source by using at least two vector hydrophones arranged in a designated sea area;

[0040] A sound source position and distance and direction module is used to calculate the direction of the wideband sound source relative to the two vector hydrophones, determine the GPS position of the sound source by the intersection of the two directions, and further determine the direction and distance of the sound source relative to the vector hydrophone;

[0041] A mode separation module is used to separate the measured signal of the vector hydrophone to obtain each mode;

[0042] An estimated sound source depth module is configured to determine the sound source depth by comparing the experimentally measured modal energy ratio of each order with the modal energy ratio of each order calculated by the sound field model.

[0043] Compared with the prior art, the present application has the following advantages:

[0044] 1. The method of the present application uses the broadband signals received by two vector hydrophones for shallow sea sound source positioning, and does not need multiple hydrophones to form an array.

[0045] 2. The method of the present application simultaneously uses the scalar and vector information of the sound field, and can realize three-dimensional positioning of the shallow sea sound source by using less spatial sampling data.

[0046] 3. Compared with the matched field positioning method, the sound source positioning using two vector hydrophones has the characteristics of simple deployment, less spatial sampling and small calculation amount, and can simultaneously realize the estimation of the azimuth, distance and depth of the sound source. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 Fig. 1 shows a flow chart of the three-dimensional positioning method of the shallow sea broadband sound source using two vector hydrophones;

[0048] Figure 2 Fig. 2 shows a schematic diagram of the deployment position of the vector hydrophone and the position of the sound source;

[0049] Fig. 3(a) shows the measured sound velocity profile in the sea experiment;

[0050] Fig. 3(b) shows the measured signal waveform of the vector hydrophone in the sea experiment;

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

[0052] Fig. 4(b) shows the estimated geographical coordinates of the sound source on the two-dimensional plane using the measured signal of the vector hydrophone;

[0053] Figure 5 Fig. 5 shows the extracted modal waveforms from the measured signal of the vector hydrophone;

[0054] Figure 6 Fig. 6 shows the modal energy ratios of different orders obtained from the measured signal of the vector hydrophone;

[0055] Figure 7 Fig. 7 shows the estimated sound source depth by the cost function. DETAILED DESCRIPTION

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

[0057] The application provides a shallow sea (sea depth of 500 m or less) sound source three-dimensional positioning method and system based on double vector hydrophones. Two vector hydrophones of appropriate depth (far from the sea surface) are arranged in a specified sea area to record wideband signals radiated by a sound source. The wideband sound source is calculated relative to the two vector hydrophones based on the vector hydrophone measurement signals, the intersection of the two azimuths is used to determine the GPS position of the sound source, and the azimuth and distance of the sound source relative to the vector hydrophone are determined. The vector hydrophone recording signals are subjected to modal separation to obtain each order mode. Finally, the energy of each order mode is calculated to obtain the energy ratio of different modes, and the sound source depth is determined by matching the experimental measurement data and the different mode energy ratios calculated by the sound field model. The method can realize three-dimensional estimation of the azimuth, distance and depth of the sound source by measuring data of only two vector hydrophones, does not need to arrange a vertical array covering the sea depth, is simple in system and easy to operate, does not need a large amount of sound field calculation, and is simple in data analysis and processing.

[0058] Embodiment 1

[0059] As shown in the shallow sea sound source three-dimensional positioning method based on double vector hydrophones, the method comprises the following steps: Figure 1

[0060] Step 1: At least two vector hydrophones are arranged in a specified sea area to record wideband signals emitted by a wideband sound source.

[0061] At least two vector hydrophones are arranged in a specified sea area, and a certain distance should be kept between the vector hydrophones. In order to ensure the posture stability of the vector hydrophones during operation, the vector hydrophones can be arranged on the bottom or a marine seismograph is used to receive the signals radiated by the wideband sound source. When the vector hydrophones are arranged, the actual azimuths of the components should be determined. The distance between the vector hydrophones and the sound source should be greater than 1 km and less than 60 km, and the frequency of the sound source should be less than 300 Hz. The experimental sea area can be approximately regarded as a horizontal constant sea environment.

[0062] In addition, the sound speed profile of seawater can be obtained by a temperature-salinity-depth measuring instrument, and information such as the depth topography of seawater can be obtained by a multi-beam system or a chart.

[0063] Step 2: The azimuth of the wideband sound source relative to the two vector hydrophones is calculated, the intersection of the two azimuths is used to determine the GPS position of the sound source, and the azimuth and distance of the sound source relative to the vector hydrophone are further determined.

[0064] The average sound energy flow method is used to calculate the azimuth of the wideband sound source relative to the two vector hydrophones based on the measured sound pressure and the horizontal components (x component and y component) of the particle velocity, the intersection of the two azimuths is used to determine the GPS position of the sound source, and the azimuth and distance of the sound source relative to the vector hydrophone are determined based on the GPS position of the sound source and the GPS position of the vector hydrophone.

[0065] ​X direction and Y direction of the vector hydrophone - the vector hydrophone can measure the sound pressure signal and the particle velocity in three directions (x, y, z) in the three-dimensional rectangular coordinate system, which are measured by independent sensors, wherein the x component and the y component are horizontal particle velocity components, and the z component is the vertical particle velocity.

[0066] Step 2 specifically comprises:

[0067] The sound pressure signal and the particle velocity x component and y component recorded by the vector hydrophone in the observation time t1 < t < t2 are respectively p(r, z, t), v x (r, z, t) and v y (r, z, t), wherein 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] The average sound intensity flow of the vector hydrophone in the x direction and the y direction can be obtained from p(r, z, t), v x (r, z, t) and v y (r, z, t) as follows:

[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] Wherein < > represents the average over time.

[0072] The azimuth of the sound source relative to the vector hydrophone can be obtained from I x (r, z) and I y (r, z) as follows:

[0073]

[0074] Suppose the azimuths of the sound source obtained from the data measured by two vector hydrophones are respectively α1 and α2, draw these two azimuths on the two-dimensional plan view of the vector hydrophone deployment position, and the intersection of the two azimuths 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 line of the line, an additional vector hydrophone can be added to make the positional relationship of the three vector hydrophones form a triangle, and the above analysis process is repeated, so that the two-dimensional geographic coordinates of the sound source can be determined, and the azimuth and distance of the sound source relative to the vector hydrophone can be further determined.

[0075] Step 3: modal separation of the vector hydrophone recording signal to obtain each order mode;

[0076] To obtain a higher signal-to-noise ratio, the signal recorded by the vector hydrophone close to the sound source is selected, and the modal separation is performed through the time-domain Warping transformation to obtain the waveform of each order mode. Specifically, it includes:

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

[0078]

[0079] Where r is the sound source distance, z is the vector hydrophone receiving depth, z s is the sound source depth, f is the frequency, S(f) is the sound source spectrum, [f1, f2] is the analyzed signal frequency range, p(r, z, z s , t) is 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 order mode, and N is the total number of modes.

[0080] The time transformation is adopted:

[0081]

[0082] Where t' is called the Warping time, and t0 is the time when the sound source reaches the receiving vector hydrophone.

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

[0084]

[0085] Where h'(t') = t' / h(t'), which is used to ensure energy conservation before and after transformation. y(r, z, z s , t') and y n (r, z, z s , t') are the signals and each order mode after Warping transformation, respectively, y n (r, z, z s , t') are separated from each other at the Warping frequency, and each mode can be separated by filtering, and then the Warping inverse transformation of y n (r, z, z s , t') can obtain the time-domain waveform p n (r, z, z s , t) of each mode.

[0086] Step 4: Determine the sound source depth by comparing the energy ratio of each order mode of the experimental measurement signal with the energy ratio of each order mode calculated by the sound field model.

[0087] According to the time-domain data pn (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, the base of the vector hydrophones is placed. 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 sea depth of the experimental sea area is about 92.2 m, the vector hydrophone (used as a bottom seismograph in the experiment) receives the broadband sound source signal, the sound source depth is about 15 m, and the signal is emitted once every 1 minute. The distance between the two vector hydrophones is about 50 km, and the sound source is about 7.11 km away from the vector hydrophone 1.

[0100] Step 2: Calculate the bearing of the broadband sound source relative to the two vector hydrophones, determine the GPS position of the sound source from the intersection of the two bearings, and further determine the bearing and distance of the sound source relative to the vector hydrophone.

[0101] As shown in FIGS. 3(a) and 3(b), the sound velocity profile and the vector hydrophone measured signal waveform in the sea experiment in this embodiment are shown. In this embodiment, the sound pressure and the particle velocity components in the x direction and the y direction measured by the two vector hydrophones in the time [t1, t2] are p1(r, z, t), v x1 (r, z, t), and p2(r, z, t), v x2 (r, z, t), v y2 (r, z, t), respectively.

[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] The bearing angles of the sound source relative to the two vector hydrophones are respectively: x1 (r, z), I y1 (r, z), and I x2 (r, z), I y2 (r, z).

[0108]

[0109] Wherein, a1 represents the azimuth of the sound source relative to the first vector hydrophone; a2 represents the azimuth of the sound source relative to the second vector hydrophone; r is the distance of the sound source; and z is the receiving depth of the vector hydrophone.

[0110] The relative positions of the two vector hydrophones and the azimuths of the sound source relative to the two vector hydrophones are plotted on a two-dimensional plan view, and the intersection of the two azimuths is the position of the sound source on the two-dimensional plan view, from which the azimuth and distance of the sound source relative to the vector hydrophone can be determined, as shown in FIGS. 4(a) and 4(b), in which the frequency used is 5-60 Hz. It should be noted that the actual azimuths of the x component and y component of the particle velocity of each vector hydrophone in the experiment are unknown, and the x direction and y direction of the two vector hydrophones in FIG. 4(b) are determined from the known azimuth of the explosive sound source signal.

[0111] Step 3: Modal separation is performed on the signal recorded by the vector hydrophone to obtain each order of modal.

[0112] The sound pressure signal measured by one of the vector hydrophones is narrowband filtered, and in this embodiment, the signal measured by the vector hydrophone closer to the sound source is selected, and the frequency range for filtering is 85-100 Hz, and the signal measured in this frequency range in the experiment contains 4 orders of modal, and the signal is denoted as p(r,z,z s ,t).

[0113] Time transformation is used:

[0114]

[0115] Wherein, t0 is the time when the sound source reaches the receiving vector hydrophone.

[0116] p(r,z,z s ,t) is changed to:

[0117]

[0118] Wherein, h'(t') = t' / h(t'). y(r,z,z s ,t') and y n (r,z,z s ,t') are the signals and each order of modal after Warping transformation, respectively, and then Warping inverse transformation is performed on y n (r,z,z s ,t') to obtain the time-domain waveform p n (r,z,z s ,t) of each modal.

[0119] In this embodiment, the 4 orders of modal obtained 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') represent 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 17.8 m, which is consistent with the actual sound source depth (about 15 m).

[0131] In the embodiment, the sound pressure signal is subjected to modal separation to obtain each order modal, and then the energy ratio of each order modal and the energy ratio of each order modal calculated by the sound field model are used to determine the sound source depth. In other embodiments, the horizontal particle velocity or the vertical particle velocity can also be subjected to modal separation to obtain each order modal, and then the energy ratio of each order modal and the energy ratio of each order modal calculated by the sound field model are used to determine the sound source depth.

[0132] Embodiment 2

[0133] The application also provides a shallow sea wideband sound source three-dimensional positioning system using a dual-vector hydrophone, which is realized based on the above method. The system comprises:

[0134] A recording wideband signal module is configured to record a wideband signal radiated by a sound source by using at least two vector hydrophones arranged in a designated sea area.

[0135] A sound source position and distance and direction module is configured to calculate the direction of the wideband sound source relative to the two vector hydrophones, determine the GPS position of the sound source from the intersection of the two directions, and further determine the direction and distance of the sound source relative to the vector hydrophones.

[0136] A modal separation module is configured to subject the signal measured by the vector hydrophone to modal separation to obtain each order modal.

[0137] An estimated sound source depth module is configured to determine the sound source depth by comparing the energy ratio of each order modal of the experimental signal and the energy ratio of each order modal calculated by the sound field model.

[0138] The application also provides a computer device, which comprises at least one processor, a memory, at least one network interface and a user interface. The various components in the device are coupled together through a bus system. It can be understood that the bus system is used to realize the connection and communication between the components. In addition to the data bus, the bus system also includes a power bus, a control bus and a state signal bus.

[0139] The user interface can include a display, a keyboard or a clicking device. For example, a mouse, a trackball, a touchpad or a touch screen, etc.

[0140] It can be appreciated that the memory in the embodiments disclosed in the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM, PROM), an erasable programmable read-only memory (Erasable PROM, EPROM), an electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or a flash memory. The volatile memory can be a random access memory (Random Access Memory, RAM) used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (Synchlink DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DRRAM). The memory described herein is intended to include but not limited to these and any other suitable types of memory.

[0141] In some embodiments, the memory stores elements, executable modules or data structures, or a subset thereof, or an extended set thereof: an operating system and an application program.

[0142] Among them, the operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., for implementing various basic services and processing hardware-based tasks. The application program includes various application programs, such as a media player (Media Player), a browser (Browser), etc., for implementing various application services. The program for implementing the method of the embodiments of the present disclosure can be included in the application program.

[0143] In the above-described embodiments, the processor can also be used to execute the steps of the above-described method by invoking the programs or instructions stored in the memory, specifically, the programs or instructions stored in the application program.

[0144] execute the steps of the above-described method.

[0145] The method can be applied to a processor or implemented by the processor. The processor can be an integrated circuit chip having a signal processing capability. In implementation, the steps of the method can be completed by an integrated logic circuit of hardware in the processor or by an instruction in the form of software. 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, discrete hardware components. The methods disclosed above can be implemented or executed by the processor. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed above can be directly embodied as a hardware code executed by the processor or a combination of hardware and software modules in the processor. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, or other mature storage media in the art. The storage media is located in the storage memory, and the processor reads information in the storage memory and combines the hardware to complete the steps of the method.

[0146] It can be understood that the embodiments described in the present application can be implemented in 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 executing functions described in the present application or a combination thereof.

[0147] For software implementation, the present application can be implemented by executing functional modules (such as processes, functions, etc.) described in the present application. The software code can be stored in a memory and executed by a processor. The memory can be implemented in the processor or outside the processor.

[0148] The application further provides a nonvolatile storage medium for storing the computer program. When the computer program is executed by a processor, each step in the above method embodiment can be implemented.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A method for three-dimensional localization of a broadband sound source in shallow water using dual vector hydrophones, comprising: Step 1: deploying at least two vector hydrophones in a designated sea area to record broadband signals radiated by the sound source; Step 2: calculating the bearing of the broadband sound source relative to the two vector hydrophones, determining the GPS position of the sound source from the intersection of the two bearings, and further determining the bearing and distance of the sound source relative to the vector hydrophones; Step 3: performing modal separation on the signal measured by the vector hydrophones to obtain each order mode; Step 4: determining the depth of the sound source by comparing the energy ratio of each order mode of the measured signal with the energy ratio of each order mode calculated from the sound field model; said Step 4 comprises: The energy of each modal of the computed sound pressure signal :​ ； wherein r is the source distance, z is the vector hydrophone receiving depth, z s is the source depth, t is time; is the time range of the measurement signal; N is the total modal number; the m energy ratio of the n mode and the mode is represented as: ； The cost function is derived from the energy ratio of the first m and second n order modes is represented as: ； wherein, represents the sound source depth calculated by the sound field model is the energy ratio of the first m order mode and the second n order mode, and the depth corresponding to the minimum value of the cost function is the estimated sound source depth.

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

3. The method for three-dimensional positioning of a shallow water broadband sound source using a dual-vector hydrophone according to claim 1, characterized in that, said Step 2 comprises: using the average sound energy flow method to determine the bearing of the sound source relative to the two vector hydrophones, obtaining the bearing angles of the sound source as follows: ； ； wherein denotes the azimuth angle of the sound source with respect to the first vector hydrophone; denotes the azimuth angle of the sound source with respect to the second vector hydrophone; denotes the sound pressure signal measured by the first vector hydrophone; denotes the particle velocity x-component measured by the first vector hydrophone; denotes the particle velocity y-component measured by the first vector hydrophone; denotes the sound pressure signal measured by the second vector hydrophone; denotes the particle velocity x-component measured by the second vector hydrophone; denotes the particle velocity y-component measured by the second vector hydrophone; denotes the average over time; r is the distance of the sound source, z is the receiving depth of the vector hydrophone; t is the time; azimuth and The intersection of the two lines is the sound source location. The GPS location of the sound source is determined in a two-dimensional plane. The azimuth and range of the sound source relative to the vector hydrophone are further determined.

4. The method for three-dimensional positioning of a shallow water broadband sound source using a dual-vector hydrophone according to claim 3, characterized in that, said Step 2 further comprises: if the sound source is on the line connecting the two vector hydrophones or on the extension of the line, adding a vector hydrophone so that the three vector hydrophones form a triangle, and then using the average sound energy flow method to determine the bearing of the sound source relative to the vector hydrophones, determining the two-dimensional geographic coordinates of the sound source, and further determining the bearing and distance of the sound source relative to the vector hydrophones.

5. The method for three-dimensional positioning of a shallow water broadband sound source using dual vector hydrophones according to claim 1, wherein, In said Step 3, the signal measured by the vector hydrophone is a sound pressure signal.

6. The method for three-dimensional positioning of a shallow water broadband sound source using a dual-vector hydrophone according to claim 5, characterized in that, said Step 3 comprises: The warping transformation is used to separate the sound pressure signal to obtain each order mode. The time transformation is used to obtain the time domain signal of each order mode wherein, is the warping time, t 0 is the time when the sound source reaches the receiving vector hydrophone, and the sound pressure signal is changed into: ； where, r is the source distance, z is the vector hydrophone receiving depth, z s is the source depth, t is time; and are the warped signal and the modal shape of order m, respectively; N is the total number of modes; then the warped inverse transform is performed to obtain the time-domain waveforms of the modes .

7. The method for three-dimensional positioning of a shallow water broadband sound source using dual vector hydrophones according to claim 1, wherein, said Step 4 further comprises: The cost function is calculated for each of the M , M <= N The cost function is calculated for each of the n , n ≠ M The cost function is calculated for each of the 8.The method of claim 1, wherein, In said Step 3, the signal measured by the vector hydrophone is a horizontal particle velocity or a vertical particle velocity.

9. A three-dimensional positioning system of a shallow water broadband sound source using a dual vector hydrophone, based on the method of any one of claims 1-8, characterized in that, The system comprises: a broadband signal recording module for recording broadband signals radiated by the sound source using at least two vector hydrophones deployed in a designated sea area; a sound source position and bearing and distance module for calculating the bearing of the broadband sound source relative to the two vector hydrophones, determining the GPS position of the sound source from the intersection of the two bearings, and further determining the bearing and distance of the sound source relative to the vector hydrophones; a modal separation module for performing modal separation on the signal measured by the vector hydrophones to obtain each order mode; a sound source depth estimation module for determining the depth of the sound source by comparing the energy ratio of each order mode of the measured signal with the energy ratio of each order mode calculated from the sound field model.

Images