A deep-sea sound source passive positioning method and system based on azimuth-angle-stripe slope blind search

Abstract

This application relates to the fields of underwater acoustic engineering, marine engineering, and sonar technology, and particularly to a passive localization method and system for deep-sea sound sources based on azimuth-fringe slope blind search. The method samples the sound source signal using a horizontal array and selects a cutoff time. After Fourier transform and phase compensation, a two-dimensional blind search based on azimuth-fringe slope is performed on the frequency domain data to obtain the corresponding spectrum. Two fringe slopes are selected from the spectrum, and the beam output angles of their direct and seabed / sea surface reflection paths are extracted. The difference between the measured fringe trajectories is calculated. A sound field calculation model is used to calculate the difference between template fringe trajectories for different sound source distances. The measured fringe trajectory difference is matched with the template fringe trajectory difference to estimate the actual distance of the sound source. This application improves beam resolution and separation capability, can separate seabed reflection path sidelobes in noise, eliminates the influence of cutoff time, and solves the problem of difficulty in estimating distance due to unknown horizontal array elevation angles.

Description

Technical Field

[0001] This application relates to the fields of underwater acoustic engineering, marine engineering, and sonar technology, and in particular to a passive localization method and system for deep-sea sound sources based on azimuth-fringe slope blind search. Background Technology

[0002] Deep-sea passive sound source localization has always been a hot research topic in the field of underwater acoustics. Traditional matched-field methods estimate the distance and depth of the sound source by matching the measured sound field with a copied sound field. However, matched-field techniques require all information from the sound field, involve large computational loads, and their performance is heavily dependent on accurate knowledge of the marine environment. Errors in environmental parameters can lead to a mismatch between the copied and measured fields, resulting in a decrease in localization performance.

[0003] The deep-sea sound field exhibits a distinct multipath arrival structure, which can be used for localization by utilizing multipath characteristics that are sensitive to sound source location and relatively tolerant of environmental changes. Existing methods generally use elevation angle information to estimate the sound source distance. Therefore, most publicly available technologies employ vector hydrophones or vertical hydrophones as receiving sensors. Since deep-sea horizontal arrays cannot directly estimate the sound source angle of arrival, sound source location estimation using horizontal arrays is more difficult than using vertical arrays. Existing methods use fringe-based beamforming to estimate the azimuth angle with high precision, decouple the solid angle from the high-precision azimuth angle to obtain the elevation angle, and then perform passive sound source localization. However, this method depends on the selection of the cutoff time. Summary of the Invention

[0004] The purpose of this application is to overcome the problem that the distance is difficult to estimate due to the unknown pitch angle in the existing horizontal array positioning method, so as to provide a passive positioning method and system for deep-sea sound sources based on azimuth angle-fringe slope blind search.

[0005] To address the aforementioned technical problems, the present application provides a passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search, comprising: Step 1: Perform time-domain sampling of the sound source signal in the deep sea using a horizontal array, select a reference array element, and choose an appropriate cutoff time based on the time-domain waveform of the reference array element; Step 2: Perform Fourier transform on the time-domain sound source signals received by each element of the horizontal array to obtain array frequency domain data, and use the truncation time to perform phase compensation on the frequency domain data; Step 3: Perform a two-dimensional blind search of azimuth angle-fringe slope on the phase-compensated frequency domain data, and obtain the azimuth angle-fringe slope map through beamforming; Step 4: Select two different fringe slopes from the azimuth-fringe slope diagram, and obtain the beam output angles of the direct path and the seabed / sea surface reflection path corresponding to the two fringe slopes respectively; Step 5: Calculate the difference in the measured fringe trajectory using the two selected fringe slope values ​​and their corresponding beam output angles; Step 6: Use the acoustic field calculation model to calculate the template stripe trajectory difference corresponding to different sound source distances in the deep sea; Step 7: Match the measured fringe trajectory difference with the template fringe trajectory difference corresponding to different distances, and estimate the actual distance of the sound source based on the matching results.

[0006] As an improvement to the above technical solution, the specific operation of step 1, which involves time-domain sampling of the sound source signal, includes: The received sound source signal is recorded by a horizontal array. The time-domain waveform obtained by each array element is ,in, The ordinal number of the array element. , The total number of elements in the horizontal array is , and the array length of the horizontal array is . L , No. The position of each element is ,satisfy , The signal sampling time is [value], and the total signal duration is [value]. ,satisfy .

[0007] As an improvement to the above technical solution, the specific operations of step 2 include: Select the Each array element serves as a reference array element; the time-domain signal recorded for the reference array elements. Select the time corresponding to the earliest arrival of the sample. ; Time-domain waveforms of each array element Perform a Fourier transform to obtain the frequency domain data of the array. ,in, For the signal frequency, satisfying Hz; based on truncation time Using the formula For frequency domain data Phase compensation is performed, where, It is an imaginary number.

[0008] As an improvement to the above technical solution, step 3 specifically includes: By selecting different fringe slopes, the beam output results are calculated using the frequency domain data after phase compensation. : ; in, It is the slope of the stripes being searched. It's from the perspective of searching. For signal frequency, It is the number of discrete frequency points, and , The total number of elements in the horizontal array. [This refers to the frequency band range under study.] It is the minimum value of the frequency band under study. It is the maximum value of the frequency band under study, satisfying Hz, The first fringe slope represents the slope along the fringe. Frequency domain data of each array element To process the center frequency of the frequency band, For the first The position of each array element To account for the frequency variation of broadband signals at the signal frequency The slope value of the stripes at that point, It is the reference speed of sound; An azimuth-fringe slope scan map is generated using the beam output results.

[0009] As an improvement to the above technical solution, the search angle satisfy: The slope of the stripes being searched The search range satisfies: Hz / m, the reference speed of sound When the waveguide sound velocity profile is known, it is the average value of the waveguide sound velocity profile; when the waveguide sound velocity profile is unknown, it is a preset value.

[0010] As an improvement to the above technical solution, step 4 specifically includes: In the azimuth-fringe slope scan, select the first fringe slope. Second stripe slope Obtain the slope of the first fringe respectively. Corresponding first beam output result Second stripe slope Corresponding second beam output result Output results from the first beam Extract the slope of the first fringe Beamforming output angle of the corresponding first direct path The output angle is formed by the beam reflected from the first seabed surface. Output results from the second beam Extracting the slope of the second fringe The corresponding beamforming output angle of the second direct path Beamforming output angle of the second seabed surface reflection path .

[0011] As an improvement to the above technical solution, in step 5, the measured stripe trajectory difference value The calculation process includes: ; in, To process the center frequency of the frequency band The corresponding angular frequency, .

[0012] As an improvement to the above technical solution, step 6 specifically includes: The BELLHOP sound field calculation model was used to calculate the difference in template stripe trajectories corresponding to different sound source distances. : ; in, Distance from the sound source Distance to the sound source calculated using BELLHOP The angle of arrival corresponding to the direct path to the location. Distance to the sound source calculated using BELLHOP The angle of arrival corresponding to the reflection path from the sea surface at the seabed.

[0013] To achieve another objective of the present invention, the present invention also provides a passive localization system for deep-sea acoustic sources based on azimuth-fringe slope blind search, comprising: The signal sampling module is used to perform time-domain sampling of sound source signals in the deep sea through a horizontal array, select reference array elements, and select an appropriate truncation time based on the time-domain waveform of the reference array elements. The frequency domain transformation and phase compensation module is used to perform Fourier transform on the time domain sound source signals received by each element of the horizontal array to obtain array frequency domain data, and to perform phase compensation on the frequency domain data using the truncation time. The two-dimensional blind search module is used to perform a two-dimensional blind search of azimuth angle-fringe slope on the phase-compensated frequency domain data, and obtains the azimuth angle-fringe slope map through beamforming. The beam output angle extraction module is used to select two different fringe slopes from the azimuth-fringe slope diagram and obtain the beam output angles of the direct path and the seabed / sea surface reflection path corresponding to the two fringe slopes respectively. The measured difference calculation module is used to calculate the measured fringe trajectory difference using two selected fringe slope values ​​and their corresponding beam output angles. The template difference calculation module is used to calculate the template fringe trajectory difference corresponding to different sound source distances in the deep sea using a sound field calculation model; and The sound source distance estimation module is used to match the measured fringe trajectory difference with the template fringe trajectory difference corresponding to different distances, and estimate the actual distance of the sound source based on the matching result.

[0014] The advantage of this application lies in its ability to improve beam resolution while maintaining the same aperture using an azimuth-fringe slope map. Furthermore, in the azimuth-fringe slope map, the energy of the seabed reflection path is weakened due to seabed reflection, resulting in sidelobes in conventional beamforming in the direct-access area, which are easily buried at low signal-to-noise ratios. However, in the azimuth-fringe slope map, the path changes from a single peak to a regular trajectory, making it easier to identify and distinguish, and can be used to separate the sidelobes corresponding to the seabed reflection path from noise. Moreover, compared to existing fringe-based beamforming localization methods, this method eliminates the influence of cutoff time through fringe trajectory difference. Attached Figure Description

[0015] Figure 1 This is a simulation of the sound velocity profile in Example 1; Figure 2 This is a time-domain diagram of the signal received by the horizontal array in Example 1; Figure 3 This is the array element position-frequency amplitude spectrum of the received signal in Example 1; Figure 4 This is the azimuth-fringe slope blind search map from Example 1; Figure 5 This is the beam output scan pattern corresponding to the stripe slope selected in Example 1; Figure 6 It is the template trajectory difference template value calculated by BELLHOP; Figure 7 This is a flowchart of the passive localization method for deep-sea sound sources based on azimuth angle-fringe slope blind search provided in Example 1. Detailed Implementation

[0016] The technical solutions provided in this application are further illustrated below with reference to the embodiments.

[0017] Example 1 This embodiment proposes a passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search. For example... Figure 7As shown, firstly, the signal is sampled in the time domain using a horizontal array, and an appropriate truncation time is selected based on the time domain waveform of the reference array element. Secondly, Fourier transform is performed on the received signal of each array element to obtain frequency domain data, and phase compensation is performed on the frequency domain data using the truncation time. Next, a two-dimensional search of azimuth angle and fringe slope is performed on the compensated data to obtain the azimuth angle-fringe slope map. Subsequently, beam outputs of two fringe slopes are selected to obtain the beam output angles of the direct path and the seabed / sea surface reflection path corresponding to the fringe slope. Then, the fringe trajectory difference is calculated using the two selected fringe slope values ​​and their corresponding beam output angles. Simultaneously, the template fringe trajectory difference corresponding to different distances is calculated using a sound field calculation model. Finally, the calculated fringe trajectory difference is matched with the template value to estimate the sound source distance.

[0018] Step 1: A horizontal array records the received signal, the first... The time-domain waveform obtained by each array element is ,in , The array length is L , No. i The position of each element is ,satisfy The unit is meters. The signal sampling time is [value], and the total signal duration is [value]. ,satisfy The unit is seconds.

[0019] Step 2: Select the first Each array element serves as a reference element, recording the time-domain signal for that element. Select an appropriate intercept time The frequency domain data of the array is obtained by performing Fourier transform on the time-domain waveforms obtained from each array element. ,satisfy For the signal frequency, satisfying Hz. For frequency domain data Perform phase compensation to satisfy ,in It is an imaginary number.

[0020] Step 3: Perform beam output under different fringe slope values ​​to meet the requirements.

[0021] in [ ] is the frequency band range under study, which meets the requirements. Hz, It is the number of discrete frequency points, satisfying . This is the reference speed of sound, measured in m / s. The average value of the waveguide sound velocity profile is usually chosen. When this value is unknown, 1500 m / s can be selected. From the perspective of searching, it satisfies . This refers to the slope of the stripes being searched; the search range is typically set to satisfy... Hz / m, this range can also be adjusted as needed. To process the center frequency of the frequency band, To account for the frequency variation of broadband signals at frequency The slope value of the stripes at that point, For broadband signal stripes at frequency Frequency offset at that location The first fringe slope represents the slope along the fringe. The frequency domain data of each array element were obtained. Finally, the azimuth-fringe slope scan pattern was obtained.

[0022] Step 4: Select two stripe slopes , Obtain the slope of the stripes , Corresponding beam output , The beam output angles corresponding to the two paths can be obtained by using the fringe slope. Beamforming output angle of direct path and seabed / sea surface reflection path , Using stripe slope Beamforming output angle of direct path and seabed / sea surface reflection path , .

[0023] Step 5: Adjust the fringe slope and Output angle , and , Substitute into the calculation of the stripe trajectory difference:

[0024] in, To process the center frequency of the frequency band The corresponding angular frequency, . Step 6: Use the BELLHOP sound field calculation model to calculate the difference in template stripe trajectories at different distances: ,in, , The distance is calculated using Bellhop. The angle of arrival corresponding to the direct path at km and the reflection path from the seabed and sea surface.

[0025] Step 7: Calculate the difference in stripe patterns. Difference from template stripe trajectory Perform matching to estimate the distance to the sound source. .

[0026] The present invention will now be further described in conjunction with the embodiments and accompanying drawings: This embodiment proposes a passive sound source localization method using a horizontal array for blind search based on deep-sea azimuth-fringe slope. The system is configured to receive a horizontal array. First, the horizontal array is placed in the water to receive the acoustic signal radiated by the sound source. Next, the signal is sampled in the time domain using the horizontal array, and an appropriate truncation time is selected based on the time domain waveform of the reference array element. Then, Fourier transform is performed on the received signal of each array element to obtain frequency domain data, and phase compensation is performed on the frequency domain data using the truncation time. Next, a two-dimensional azimuth-fringe slope search is performed on the compensated data to obtain an azimuth-fringe slope map. Subsequently, beam outputs for two fringe slopes are selected, and the beam output angles of the direct path and the seabed / sea surface reflection path corresponding to these fringe slopes are obtained. Then, the fringe trajectory difference is calculated using the two selected fringe slope values ​​and their corresponding beam output angles. Simultaneously, a sound field calculation model is used to calculate the template fringe trajectory difference corresponding to different distances. Finally, the calculated fringe trajectory difference is matched with the template value to estimate the sound source distance. Based on the multipath arrival structure characteristics of deep-sea sound field propagation, this invention proposes a passive localization method adapted to deep-sea horizontal arrays. It mainly utilizes the trajectory difference corresponding to different paths of the sound source in the azimuth-fringe slope search map to achieve passive localization of the sound source.

[0027] This embodiment uses simulated signal data emitted by a sound source in the direct-access area, received by a horizontal array arranged on the deep seabed, as an example. The sound velocity profile is as follows: Figure 1 The simulated seawater depth is 3000m, and the seawater density is 1.0g / L. Seawater absorbs sound silently. The speed of sound on the seabed is 1528 m / s, and the density is 1.8 g / L. Absorption at seabed: 0.3 dB / , Indicates the wavelength of the sound wave; the spectrum of the sound source. =1, sound source depth is 200m; uniform horizontal receiving array aperture is 500m, array element spacing The deployment depth is 2990m; the horizontal distance between the sound source and the center point of the receiving array is 7km, and the azimuth angle is 60°. Background noise is not considered in the simulation.

[0028] Step 1: Receive signals from the horizontal array pair Record it, among which ; array length is L= 500m, the i The position of each element is The unit is meters (symbol) m ). The signal sampling time is [value], and the total signal duration is [value]. ,satisfy The unit is seconds (symbol) s ).

[0029] Step 2: Select the 101st array element as the reference signal and analyze the time-domain signal recorded by this element. The time-domain signal received by the reference array element in this embodiment is as follows: Figure 2 As shown. Select the cutoff time. =4.5s. Fourier transforms are performed on the time-domain waveforms obtained from each array element to obtain the array's frequency-domain data. ,satisfy For the signal frequency, satisfying Hz. For frequency domain data Perform phase compensation to satisfy The obtained sound pressure amplitude spectrum of array element position-frequency is as follows: Figure 3 As shown.

[0030] Step 3: Perform a blind search for the maximum beam output value under different fringe slope values, and construct the cost function through beamforming as follows.

[0031] The frequency band studied is [30, 70] Hz, with 4001 discrete frequency points. Reference speed of sound. The value was chosen as 1521 m / s. From the perspective of searching, it satisfies . It is the slope of the stripes being searched, and the search range is set to satisfy... Hz / m. Center frequency of the processed frequency band. =50Hz, To account for the frequency variation of broadband signals at frequency The slope value of the stripes at that point, For broadband signal stripes at frequency The frequency offset at that point. This is obtained as follows: Figure 4 The azimuth-fringe slope search diagram is shown.

[0032] Step 4: Select two stripe slopes , Obtain the slope of the stripes , Corresponding beam output , Beam output such as Figure 5 As shown, the beam output angles corresponding to the two paths can be obtained as follows: , , , .

[0033] Step 5: Adjust the fringe slope and Output angle , and , Substitute into the calculation of the stripe trajectory difference: Step 6: Use the BELLHOP sound field calculation model to calculate the difference in template stripe trajectories at different distances: ,in, , The distance is calculated using Bellhop. The angle of arrival corresponding to the direct path at km and the seabed / sea surface reflection path is as follows. The calculated template fringe trajectory difference is as follows: Figure 6 As shown.

[0034] Step 7: Calculate the difference in stripe patterns. Difference from template stripe trajectory Perform matching to estimate the distance to the sound source. km, the elevation angle of the direct wave is =20.05°. The distance to the sound source estimated by this method is close to the actual distance to the sound source.

[0035] Example 2 The deep-sea acoustic source passive localization system based on azimuth angle-fringe slope blind search provided in this embodiment includes: The signal sampling module is used to perform time-domain sampling of sound source signals in the deep sea through a horizontal array, select reference array elements, and select an appropriate truncation time based on the time-domain waveform of the reference array elements. The frequency domain transformation and phase compensation module is used to perform Fourier transform on the time domain sound source signals received by each element of the horizontal array to obtain array frequency domain data, and to perform phase compensation on the frequency domain data using the truncation time. The two-dimensional blind search module is used to perform a two-dimensional blind search of azimuth angle-fringe slope on the phase-compensated frequency domain data, and obtains the azimuth angle-fringe slope map through beamforming. The beam output angle extraction module is used to select two different fringe slopes from the azimuth-fringe slope diagram and obtain the beam output angles of the direct path and the seabed / sea surface reflection path corresponding to the two fringe slopes respectively. The measured difference calculation module is used to calculate the measured fringe trajectory difference using two selected fringe slope values ​​and their corresponding beam output angles. The template difference calculation module is used to calculate the template fringe trajectory difference corresponding to different sound source distances in the deep sea using a sound field calculation model; and The sound source distance estimation module is used to match the measured fringe trajectory difference with the template fringe trajectory difference corresponding to different distances, and estimate the actual distance of the sound source based on the matching result.

[0036] The positioning method and system proposed in this invention target sound sources exhibiting beam splitting in the azimuth-fringe slope spectrum of a horizontal array. Based on the beam splitting trajectory equation in the azimuth-fringe slope spectrum, it increases the output beam spacing of different paths by selecting specific fringe slopes, thus separating paths that were originally inseparable in the azimuth-fringe slope domain, improving beam separation capability without changing the array aperture. Furthermore, it utilizes fringe trajectory differences to eliminate the dependence of existing fringe-based beamforming azimuth estimation methods on truncation time compensation, thereby achieving passive positioning of fringe-based sound sources without relying on truncation time compensation.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention 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 the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search, comprising: Step 1: Perform time-domain sampling of the sound source signal in the deep sea using a horizontal array, select a reference array element, and choose an appropriate cutoff time based on the time-domain waveform of the reference array element; Step 2: Perform Fourier transform on the time-domain sound source signals received by each element of the horizontal array to obtain array frequency domain data, and use the truncation time to perform phase compensation on the frequency domain data; Step 3: Perform a two-dimensional blind search of azimuth angle-fringe slope on the phase-compensated frequency domain data, and obtain the azimuth angle-fringe slope map through beamforming; Step 4: Select two different fringe slopes from the azimuth-fringe slope diagram, and obtain the beam output angles of the direct path and the seabed / sea surface reflection path corresponding to the two fringe slopes respectively; Step 5: Calculate the difference in the measured fringe trajectory using the two selected fringe slope values ​​and their corresponding beam output angles; Step 6: Use the acoustic field calculation model to calculate the template stripe trajectory difference corresponding to different sound source distances in the deep sea; Step 7: Match the measured fringe trajectory difference with the template fringe trajectory difference corresponding to different distances, and estimate the actual distance of the sound source based on the matching results.

2. The passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search according to claim 1, characterized in that, The specific operations for time-domain sampling of the sound source signal in step 1 include: The received sound source signal is recorded by a horizontal array. The time-domain waveform obtained by each array element is ,in, The ordinal number of the array element. , The total number of elements in the horizontal array is , and the array length of the horizontal array is . L , No. The position of each element is ,satisfy , The signal sampling time is [value], and the total signal duration is [value]. ,satisfy .

3. The passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search according to claim 1, characterized in that, The specific operations of step 2 include: Select the Each array element serves as a reference array element; the time-domain signal recorded for the reference array elements. Select the time corresponding to the earliest arrival of the sample. ; Time-domain waveforms of each array element Perform a Fourier transform to obtain the frequency domain data of the array. ,in, For the signal frequency, satisfying Hz; based on truncation time Using the formula For frequency domain data Phase compensation is performed, where, It is an imaginary number.

4. The passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search according to claim 3, characterized in that, Step 3 specifically includes: By selecting different fringe slopes, the beam output results are calculated using the frequency domain data after phase compensation. : ； in, It is the slope of the stripes being searched. It's from the perspective of searching. For signal frequency, It is the number of discrete frequency points, and , The total number of elements in the horizontal array. [This refers to the frequency band range under study.] It is the minimum value of the frequency band under study. It is the maximum value of the frequency band under study, satisfying Hz, The first fringe slope represents the slope along the fringe. Frequency domain data of each array element To process the center frequency of the frequency band, For the first The position of each array element To account for the frequency variation of broadband signals at the signal frequency The slope value of the stripes at that point, It is the reference speed of sound; An azimuth-fringe slope scan map is generated using the beam output results.

5. The passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search according to claim 4, characterized in that, The search angle satisfy: The slope of the stripes being searched The search range satisfies: Hz / m, the reference speed of sound When the waveguide sound velocity profile is known, it is the average value of the waveguide sound velocity profile; when the waveguide sound velocity profile is unknown, it is a preset value.

6. The passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search according to claim 1, characterized in that, Step 4 specifically includes: In the azimuth-fringe slope scan, select the first fringe slope. Second stripe slope Obtain the slope of the first fringe respectively. Corresponding first beam output result Second stripe slope Corresponding second beam output result Output results from the first beam Extract the slope of the first fringe Beamforming output angle of the corresponding first direct path The output angle of the beam formed by the reflection path from the first seabed surface Output results from the second beam Extracting the slope of the second fringe The corresponding beamforming output angle of the second direct path Beamforming output angle of the second seabed surface reflection path .

7. The passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search according to claim 6, characterized in that, In step 5, the measured stripe trajectory difference The calculation process includes: ； in, To process the center frequency of the frequency band The corresponding angular frequency, .

8. The passive localization method for deep-sea sound sources based on azimuth-fringe slope blind search according to claim 1, characterized in that, Step 6 specifically includes: The BELLHOP sound field calculation model was used to calculate the difference in template stripe trajectories corresponding to different sound source distances. : ； in, Distance from the sound source Distance to the sound source calculated using BELLHOP The angle of arrival corresponding to the direct path to the location. Distance to the sound source calculated using BELLHOP The angle of arrival corresponding to the reflection path from the sea surface at the seabed.

9. A passive localization system for deep-sea acoustic sources based on azimuth-fringe slope blind search, comprising: The signal sampling module is used to perform time-domain sampling of sound source signals in the deep sea through a horizontal array, select reference array elements, and select an appropriate truncation time based on the time-domain waveform of the reference array elements. The frequency domain transformation and phase compensation module is used to perform Fourier transform on the time domain sound source signals received by each element of the horizontal array to obtain array frequency domain data, and to perform phase compensation on the frequency domain data using the truncation time. The two-dimensional blind search module is used to perform a two-dimensional blind search of azimuth angle-fringe slope on the phase-compensated frequency domain data, and obtains the azimuth angle-fringe slope map through beamforming. The beam output angle extraction module is used to select two different fringe slopes from the azimuth-fringe slope diagram and obtain the beam output angles of the direct path and the seabed / sea surface reflection path corresponding to the two fringe slopes respectively. The measured difference calculation module is used to calculate the measured fringe trajectory difference using two selected fringe slope values ​​and their corresponding beam output angles. The template difference calculation module is used to calculate the template stripe trajectory difference corresponding to different sound source distances in the deep sea using a sound field calculation model. and The sound source distance estimation module is used to match the measured fringe trajectory difference with the template fringe trajectory difference corresponding to different distances, and estimate the actual distance of the sound source based on the matching result.

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