Horizontal linear array passive ranging method and system based on surface waveguide leakage effect

Abstract

The invention provides a horizontal array passive ranging method and system based on a surface waveguide leakage effect, and the method comprises the steps: converting a time domain signal received by a horizontal array into a frequency domain, and carrying out the beam forming to obtain a spatial spectrum; performing incoherent accumulation on the spatial spectrum on a frequency axis to obtain a broadband spatial spectrum, and extracting an angle position corresponding to a spectrum peak in the broadband spatial spectrum; selecting the minimum angle corresponding to the peak value, and obtaining the azimuth angle of the sound source relative to the horizontal array through a diffraction ray theory correction formula; correcting the angle corresponding to the spectrum peak of the seabed reflection wave in the broadband spatial spectrum through the relation between the spatial angle and the azimuth angle, so as to obtain the arrival angle of the primary seabed reflection signal; and obtaining a distance estimation value of the sound source by using the estimated angle of arrival of the primary seabed reflection signal and a ray geometric formula. According to the method, the problem of distance-azimuth coupling occurring when a horizontal line array is used for sound source positioning is solved, and an accurate estimation value of the sound source distance can be given.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of underwater acoustic array signal processing, underwater acoustic detection, underwater acoustic positioning and sonar technology, and particularly relates to a horizontal line array passive ranging method and system based on surface waveguide leakage effect. BACKGROUND

[0002] Under the condition of deep sea waveguide, when the sound source is located within a few hundred meters near the sea surface, the direct sound zone formed near the sea surface can only expand a small range, so the horizontal array often needs to work in the shadow zone. In the shadow zone, there is no direct signal and sea surface reflection signal. The first bottom reflection signal and the surface waveguide leakage signal are the main received signal components. The method of using the multipath time delay and arrival angle characteristics of the first bottom reflection signal to realize sound source positioning has been proposed, but the correlation between the multipath signals reflected by the real sea bottom is poor, the time delay estimation error is large, and the sound field model needs to be calculated to match the multipath characteristics, which also brings the problems of sensitivity to environmental prior knowledge and large amount of calculation. The arrival angle of the first bottom reflection signal is easier to extract than the multipath time delay, is less affected by the real sea bottom reflection, and according to the ray geometry, it has a simple geometric relationship with the sound source distance. However, for the horizontal array, there is a problem of azimuth-angle coupling, so the arrival angle of the first bottom reflection signal cannot be accurately estimated. SUMMARY

[0003] The purpose of the present application is to overcome the defects that the prior art has the problem of azimuth-angle coupling, cannot accurately estimate the arrival angle of the first bottom reflection signal, and cannot accurately estimate the sound source distance.

[0004] In order to achieve the above purpose, the present application provides a horizontal line array passive ranging method based on surface waveguide leakage effect, comprising: Step 1: obtaining the time domain sound pressure signal of the target sound source by using the horizontal line array, and performing Fourier transform on the time domain sound pressure signal to obtain a frequency domain signal; Step 2: performing beamforming on the frequency domain signal to obtain the spatial spectrum of the target sound source; Step 3: non-coherently accumulating the obtained spatial spectrum on the frequency axis to obtain a broadband spatial spectrum; extracting the angle value corresponding to the peak value from the amplitude of the broadband spatial spectrum, and taking the smallest angle; Step 4: correcting the smallest angle by using the diffraction ray theory to obtain the estimated value of the azimuth angle of the target sound source; Step 5: using the spectral peak position corresponding to the first bottom reflection signal extracted from the spatial spectrum, and according to the relationship between the arrival angle and the azimuth angle, obtaining the estimated value of the arrival angle of the first bottom reflection signal; Step 6: Using the estimated value of the angle of arrival of the first bottom bounce, the estimated value of the range of the target sound source is obtained according to the ray geometry.

[0005] As an improvement of the above method, the Fourier transform is performed on the time-domain sound pressure signal to obtain a frequency-domain signal, denoted as: ; wherein, denotes the frequency-domain signal on each array element; denotes the time-domain sound pressure signal of the target sound source; denotes the frequency; is the imaginary unit; is the number of array elements; denotes the distance between the th array element and the sound source; denotes the time.

[0006] As an improvement of the above method, the beamforming is performed on the frequency-domain signal to obtain the spatial spectrum of the target sound source, denoted as: ; wherein, denotes the spatial spectrum; denotes the sound speed at the array; denotes the horizontal line array element spacing; denotes the search angle; denotes the frequency; is the imaginary unit; is the number of array elements; denotes the frequency-domain signal on each array element.

[0007] As an improvement of the above method, the obtained spatial spectrum is non-coherently accumulated on the frequency axis to obtain a broadband spatial spectrum, denoted as: ; wherein, denotes the broadband spatial spectrum; denotes the spatial spectrum; denotes the search angle; denotes the frequency.

[0008] As an improvement of the above method, the smallest angle is corrected using the diffraction ray theory to obtain the estimated value of the azimuth angle of the target sound source, denoted as: ; wherein, denotes the estimated value of the azimuth angle of the target sound source; denotes the sound speed at the interface of the surface waveguide and the thermocline; denotes the sound speed at the array; represents the minimum angle of the angle value corresponding to the peak value of the amplitude of the wideband spatial spectrum.

[0009] As an improvement of the above method, the arrival angle estimation value of the first bottom reflection signal is obtained according to the relationship between the arrival angle and the azimuth angle, and is represented as: ; wherein, represents the arrival angle estimation value of the first bottom reflection signal; represents the spectral peak position corresponding to the first bottom reflection signal extracted from the spatial spectrum; represents the estimation value of the azimuth angle of the target sound source.

[0010] As an improvement of the above method, the distance estimation value of the target sound source is obtained according to the ray geometric relationship by using the arrival angle estimation value of the first bottom reflection signal, and is represented as: ; wherein, represents the distance estimation value of the target sound source; represents the depth of seawater; represents the arrival angle estimation value of the first bottom reflection signal.

[0011] The application also provides a horizontal line array passive ranging system based on surface waveguide leakage effect, which is realized based on the above method, and the system comprises: a detection and conversion module, which is used for obtaining the time-domain sound pressure signal of the target sound source by using the horizontal line array, and obtaining the frequency-domain signal by performing Fourier transform on the time-domain sound pressure signal; an acquisition spatial spectrum module, which is used for performing beam forming on the frequency-domain signal to obtain the spatial spectrum of the target sound source; an acquisition minimum angle module, which is used for non-coherent accumulation of the obtained spatial spectrum on the frequency axis to obtain a wideband spatial spectrum, extracting the angle value corresponding to the peak value of the amplitude of the wideband spatial spectrum, and taking the minimum angle; an estimation azimuth angle module, which is used for correcting the minimum angle by using the diffraction ray theory to obtain the estimation value of the azimuth angle of the target sound source; an estimation arrival angle module, which is used for obtaining the arrival angle estimation value of the first bottom reflection signal according to the relationship between the arrival angle and the azimuth angle by using the spectral peak position corresponding to the first bottom reflection signal extracted from the spatial spectrum; an estimation sound source distance module, which is used for obtaining the distance estimation value of the target sound source according to the ray geometric relationship by using the arrival angle estimation value of the first bottom reflection signal.

[0012] Compared with the prior art, the application has the following advantages: 1. Compared with the multipath delay matching method, the method of the present invention does not need to extract multipath delay features that are greatly affected by the actual seabed from the signal, thus having stronger robustness; 2. Apart from needing to know the sound velocity at the lower boundary of the surface waveguide and the sound velocity at the horizontal array deployment depth, there are no other requirements for prior environmental knowledge; 3. No need to use a sound field calculation model to calculate the matching sound field, greatly reducing the amount of computation. Attached Figure Description

[0013] Figure 1 The diagram shows a flowchart of a passive ranging method for horizontal linear arrays based on the leakage effect of surface waveguides. Figure 2 The diagram shows the geometric relationship between the sound source and the array position. Figure 3 The image shown is a deep-sea sound velocity profile used in the simulation example. Figure 4 The image shows the energy distribution of the signal received on the horizontal array in the frequency-angle domain after Fourier transform and beamforming, as well as the broadband spatial spectrum obtained by incoherent accumulation on the frequency axis. Figure 5 The figure shows the distance estimation results under different azimuth angles and distances of the sound source. Detailed Implementation

[0014] The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0015] To provide a clearer picture of the invention, the technical terms used in the invention will be described below.

[0016] Sound shadow zone: refers to the area where sound rays cannot reach due to obstacles or refraction, that is, the area with almost no sound.

[0017] Ocean surface waveguide mode: This is a special type of atmospheric waveguide that occurs over the ocean. This waveguide mode typically occurs in relatively stable atmospheric environments, with a stable temperature inversion layer in the lower atmosphere and atmospheric humidity decreasing with altitude. These conditions cause the atmospheric corrected refractive index to decrease upwards, thus forming a surface waveguide.

[0018] Surface waveguide leakage signal: The signal emitted by the target sound source is diffracted on the ocean surface beneath the surface waveguide, thus forming a surface waveguide leakage signal. Studies have shown that this surface waveguide leakage signal is more stable in terms of propagation angle characteristics, and therefore has stronger robustness.

[0019] Deep sea: Sea areas with a depth of 200m or more.

[0020] Thermocline: a layer of water 100-200 m below the sea surface where temperature and density change greatly, it is the thin warm water layer of the upper layer and the thick cold water layer of the lower layer.

[0021] Embodiment 1 The method of the present application utilizes the surface waveguide leakage effect, estimates the azimuth angle of the sound source according to the diffraction ray theory, solves the azimuth angle-arrival angle coupling problem of the horizontal array, and gives an accurate estimation value of the arrival angle of the first bottom-reflected signal. Finally, the distance estimation value of the sound source is given by using the ray geometry formula. Specifically, the method first transforms the time-domain signal received by the horizontal array into the frequency domain; secondly, the spatial spectrum is obtained by beamforming the obtained frequency-domain signal; then, the non-coherent accumulation of the obtained spatial spectrum on the frequency axis is carried out to obtain the peak value corresponding to the angle value in the broadband spatial spectrum; then the minimum angle corresponding to the peak value is selected, which is the spectral peak position corresponding to the surface waveguide leakage signal, and the estimation value of the azimuth angle of the sound source relative to the horizontal array is obtained by using the correction formula of the diffraction ray theory. According to the relationship between the spatial angle and the azimuth angle, the estimation value of the arrival angle of the first bottom-reflected signal is given. Finally, according to the ray geometry relationship, the estimation value of the distance of the sound source can be given by using the arrival angle of the first bottom-reflected signal. The method of the present application is suitable for the horizontal array working in the shadow zone in the deep sea environment with surface waveguide. Compared with the multipath time delay matching method, the method of the present application has higher robustness, and in addition to the known surface waveguide lower boundary sound speed and the sound speed at the depth of the horizontal array, it has no other requirements for the prior knowledge of the environment. And without using the sound field calculation model, the calculation amount is greatly reduced.

[0022] As Figure 1 shown, the horizontal line array passive ranging method based on the surface waveguide leakage effect provided by the present application comprises the following steps: Step 1: obtaining the time-domain sound pressure signal of the sound source by using the horizontal line array pre-deployed in the underwater environment with surface waveguide and working in the shadow zone , wherein represents time, and represents the distance between the th array element and the sound source, and the Fourier transform of formula (1) is carried out to obtain the frequency-domain signal on each array element .

[0023] (1) wherein, represents the time-domain sound pressure signal of the target sound source; represents frequency, is an imaginary unit, is the number of array elements.

[0024] Preferably, the distance from the target sound source to the horizontal line array is 50-200 m. Moreover, the element aperture of the horizontal line array is not limited, and the element interval can be set to half the wavelength of the frequency of the target sound source, without the emergence of a fan.

[0025] Step 2: Perform beamforming on the frequency domain signal on the element domain using formula (2) to obtain the spatial spectrum .

[0026] (2) wherein, is the sound speed at the array, is the element spacing of the horizontal line array, is the search angle.

[0027] Step 3: Incoherently accumulate the obtained spatial spectrum on the frequency axis using formula (3) to obtain a wideband spatial spectrum . Then extract the angle value corresponding to the peak value from the amplitude of the obtained wideband spatial spectrum, and take the smallest angle , which corresponds to the surface waveguide leakage signal.

[0028] (3) Step 4: Perform correction on using formula (4) derived from the diffraction ray theory, that is, the estimated value of the target azimuth can be obtained.

[0029] (4) wherein, is the sound speed at the intersection of the surface waveguide and the thermocline, is the inverse cosine function.

[0030] Step 5: Using the target azimuth angle estimate value estimated in step 4 and the spectral peak position corresponding to the first sea bottom reflection signal extracted from the spatial spectrum , according to the relationship between the arrival angle and the azimuth angle, the arrival angle estimate value of the first sea bottom reflection signal can be obtained. (5) Step 6: Using the arrival angle estimate value of the first sea bottom reflection signal obtained in step 5, according to the ray geometric relationship, the distance estimate value of the sound source can be obtained.

[0031] (6) wherein, is the depth of the sea water.

[0032] Simulation Example Simulation Parameters: The waveguide environment is a deep sea sound waveguide with a surface waveguide, the depth is , the sound speed profile of the sea water is shown in Fig. 3, the density is , the sound speed of the lower layer bottom is , the density is , the seabed attenuation coefficient is , wherein represents the wavelength of the sound wave. The thickness of the surface waveguide is , the sound speed gradient is . The frequency band range of the sound source signal is 400-450 Hz, the frequency sampling interval is 1 Hz, the distance from the sound source to the array varies from to . The array towing depth is fixed at 50 m, the array aperture is , and the element interval is 1 m. The schematic diagram of the geometry position of the sound source and the array in the simulation is shown in Figure 2 . The sound speed profile of the deep sea used in the simulation is shown in Figure 3 . When the distance of the sound source is Figure 4 and located in the end-fire direction of the array, the spatial spectrum at different frequencies and the broadband spatial spectrum obtained by spatial spectrum analysis of the array received signal are shown in . The estimation result diagram of the distance of the sound source under different azimuth angles of the sound source by using the method of the present application is shown in Figure 5 Step 1: using the array aperture of 256 m and the element interval of 1 m in the present example, and selecting the element closest to the sound source as the reference element, the time domain Fourier transform is performed on the sound signal recorded by the array, the signal is transformed to the frequency domain by using formula (1), the signal with the frequency band of 400-450 Hz is intercepted, and

[0033] is obtained.

[0034] Step 2: according to formula (2), the frequency domain signal is transformed to the angle domain to obtain the spatial spectrum . In this example, the search angle range is from to , and the angle interval is . Among them, the result at the receiving depth of , the distance of , and the azimuth angle of the sound source of is shown in Figure 4 . According to Figure 4 , it can be known by using the ocean acoustic theory analysis that the spectral peak representing the surface waveguide leakage signal has the smallest angle value​ The spectral peak representing a single seabed reflection signal has the second smallest angular value. .

[0035] Step 3: Using formula (3), analyze the obtained spatial spectrum. Incoherent accumulation is performed on the frequency axis to obtain the broadband spatial spectrum. From the obtained broadband spatial spectrum Extract the angle corresponding to the peak value and select the smallest angle as the minimum value. ,like Figure 4 The location is marked by the red dashed line in the lower half of the image. Step 4: Correct it using formula (4), where the sound velocity at the array is... surface waveguide boundary sound velocity The estimated azimuth angle is obtained. .

[0036] Step 5: Extract the spectral peak angle corresponding to the primary seabed reflection signal from the broadband spatial spectrum. Substituting this into formula (5) and correcting it, we can obtain an estimate of the angle of arrival of the seabed reflection signal. .

[0037] Step 6: Calculate the angle of arrival of the first seabed reflection signal estimated in Step 5. Substituting into formula (6), we can obtain an estimate of the sound source distance. .

[0038] Finally, the distance estimation results under different sound source azimuth angles and sound source distances are recorded and displayed. Figure 5 In the simulation conditions of this example, the relative position of the distance estimation result of the method of the present invention stabilizes at... The results provide a relatively accurate estimate.

[0039] Example 2 This application also provides a horizontal linear array passive ranging system based on the surface waveguide leakage effect, implemented using the above method, the system comprising: The detection and conversion module is used to obtain the time-domain sound pressure signal of the target sound source using a horizontal linear array, and to perform a Fourier transform on the time-domain sound pressure signal to obtain a frequency-domain signal. A spatial spectrum acquisition module is used to perform beamforming on the frequency domain signal to obtain the spatial spectrum of the target sound source. The minimum angle acquisition module is used to incoherently accumulate the obtained spatial spectrum on the frequency axis to obtain a broadband spatial spectrum; extract the angle value corresponding to the peak value from the amplitude of the broadband spatial spectrum, and take the minimum angle among them; An estimated azimuth angle module is configured to correct the minimum angle by using a diffraction ray theory to obtain an estimated value of the azimuth angle of the target sound source; An estimated arrival angle module is configured to obtain an estimated value of the arrival angle of the first bottom-reflected signal according to the relationship between the arrival angle and the azimuth angle by using the spectral peak position of the first bottom-reflected signal extracted from the spatial spectrum. An estimated sound source distance module is configured to obtain an estimated value of the distance of the target sound source according to a ray geometry relationship by using the estimated value of the arrival angle of the first bottom-reflected signal.

[0040] The present application can also provide 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 communication between the components. In addition to the data bus, the bus system also includes a power bus, a control bus and a status signal bus.

[0041] 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.

[0042] It can be understood that the memory in the embodiments of 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.

[0043] 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.

[0044] Among them, the operating system includes various system programs, such as framework layer, core library layer, driver layer, etc., for implementing various basic services and processing hardware-based tasks. The application program includes various application programs, such as media player (Media Player), 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.

[0045] In the above-mentioned embodiments, the processor can also be used to: execute the steps of the above method.

[0046] 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 mediums in the art. The storage medium 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.

[0047] 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.

[0048] For software implementation, the present application can be implemented by executing function 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.

[0049] The application can also provide a nonvolatile storage medium for storing a computer program. When the computer program is executed by a processor, each step in the above method embodiments can be implemented.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. 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 technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A passive ranging method for a horizontal linear array based on surface waveguide leakage effect, comprising: Step 1: Obtain the time-domain sound pressure signal of the target sound source using a horizontal linear array, and perform a Fourier transform on the time-domain sound pressure signal to obtain the frequency-domain signal; Step 2: Perform beamforming on the frequency domain signal to obtain the spatial spectrum of the target sound source; Step 3: Incoherently accumulate the obtained spatial spectrum on the frequency axis to obtain a broadband spatial spectrum; extract the angle value corresponding to the peak value from the amplitude of the broadband spatial spectrum, and take the smallest angle among them; Step 4: Correct the minimum angle using diffraction theory to obtain an estimated value of the target sound source azimuth angle; Step 5: Using the spectral peak position of the corresponding first seabed reflection signal extracted from the spatial spectrum, and based on the relationship between the angle of arrival and the azimuth, obtain the estimated value of the angle of arrival of the first seabed reflection signal. Step 6: Using the estimated angle of arrival of the first seabed reflection signal, and based on the ray geometry, obtain the estimated distance to the target sound source.

2. The passive ranging method for a horizontal linear array based on surface waveguide leakage effect according to claim 1, characterized in that, The frequency domain signal obtained by performing a Fourier transform on the time-domain sound pressure signal is expressed as follows: ； in, This represents the frequency domain signal on each array element; Represents the time-domain sound pressure signal of the target sound source; Indicates frequency; The imaginary unit; The number of array elements; Indicates the first The distance between each array element and the sound source; Indicates time.

3. The passive ranging method for horizontal linear arrays based on surface waveguide leakage effect according to claim 1, characterized in that, The beamforming of the frequency domain signal yields the spatial spectrum of the target sound source, which is expressed as follows: ； in, Represents the spatial spectrum; Indicates the speed of sound at the array location; Indicates the spacing between elements of a horizontal linear array; Indicates the search angle; Indicates frequency; The imaginary unit; The number of array elements; This represents the frequency domain signal on each array element.

4. The passive ranging method for horizontal linear arrays based on surface waveguide leakage effect according to claim 1, characterized in that, The obtained spatial spectrum is incoherently accumulated along the frequency axis to obtain a broadband spatial spectrum, which is expressed as: ； in, Represents the broadband spatial spectrum; Represents the spatial spectrum; Indicates the search angle; Indicates frequency.

5. The passive ranging method for a horizontal linear array based on surface waveguide leakage effect according to claim 1, characterized in that, The minimum angle is corrected using diffraction theory to obtain an estimated value of the target sound source azimuth angle, expressed as: ； in, This represents an estimated value of the azimuth angle of the target sound source; This represents the sound velocity at the interface between the surface waveguide and the thermocline. Indicates the speed of sound at the array location; This represents the minimum angle from which the peak value corresponding to the amplitude of the broadband spatial spectrum is extracted.

6. The passive ranging method for a horizontal linear array based on surface waveguide leakage effect according to claim 1, characterized in that, The estimated angle of arrival of a first-order seabed reflected signal is obtained based on the relationship between the angle of arrival and the azimuth angle, and is expressed as follows: ； in, This represents the estimated angle of arrival of a single seabed reflected signal; This indicates the position of the spectral peak of the corresponding first seabed reflection signal extracted from the spatial spectrum; This represents the estimated azimuth angle of the target sound source.

7. The passive ranging method for horizontal linear arrays based on surface waveguide leakage effect according to claim 1, characterized in that, The distance estimate of the target sound source is obtained by using the estimated angle of arrival of the first seabed reflection signal and based on the ray geometry, as expressed as: ； in, This represents the estimated distance to the target sound source; Indicates seawater depth; This represents the estimated angle of arrival of a single seabed reflected signal.

8. A passive ranging system for a horizontal linear array based on the leakage effect of surface waveguides, implemented according to the method described in any one of claims 1-7, characterized in that, The system includes: The detection and conversion module is used to obtain the time-domain sound pressure signal of the target sound source using a horizontal linear array, and to perform a Fourier transform on the time-domain sound pressure signal to obtain a frequency-domain signal. A spatial spectrum acquisition module is used to perform beamforming on the frequency domain signal to obtain the spatial spectrum of the target sound source. The minimum angle acquisition module is used to incoherently accumulate the obtained spatial spectrum on the frequency axis to obtain a broadband spatial spectrum; extract the angle value corresponding to the peak value from the amplitude of the broadband spatial spectrum, and take the minimum angle among them; An azimuth estimation module is used to correct the minimum angle using diffraction theory to obtain an estimated value of the azimuth angle of the target sound source. The angle-of-arrival estimation module is used to obtain an estimated angle-of-arrival value for a primary seabed reflection signal by utilizing the spectral peak position of the corresponding primary seabed reflection signal extracted from the spatial spectrum, based on the relationship between the angle of arrival and the azimuth. The sound source distance estimation module is used to obtain the distance estimate of the target sound source by using the estimated angle of arrival of the seabed reflection signal and the ray geometry.

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