A target detection method and system based on a deep-sea large-aperture vertical array

Abstract

The present application relates to the field of underwater acoustic engineering, ocean engineering and sonar technology, and particularly relates to a target detection method and system based on a deep-sea large-aperture vertical array. The method comprises the following steps: step 1: receiving a time-domain signal radiated by a target sound source through a large-aperture vertical array arranged on the seabed in deep sea; step 2: performing fast Fourier transform on the time-domain signal received by each array element to obtain a corresponding signal spectrum; step 3: calculating a steering vector according to the phase difference of the depth of each array element of the large-aperture vertical array relative to a reference array element; based on the steering vector, processing the signal spectrum of different array elements through a spatial power spectrum estimation method to obtain a spatial power spectrum estimation result under different angles of arrival angles, so as to realize detection of the target sound source.

Description

Technical Field

[0001] This invention relates to the fields of underwater acoustic engineering, marine engineering and sonar technology, and in particular to a target detection method and system based on a deep-sea large-aperture vertical array. Background Technology

[0002] In deep-sea environments, bottom-mounted vertical arrays are a common formation for detecting and locating sound sources. Utilizing the direct sound field propagation characteristics, they can achieve blind-zone-free detection of sound sources within short to medium ranges. As the target sound source level decreases and the number of interfering vessels increases, the required array aperture becomes larger. More receiving elements and a larger array aperture can improve array gain during beamforming, as well as enhance angular resolution and the ability to suppress interference sources.

[0003] However, as the array aperture gradually increases, the performance of spatial power spectrum estimation methods based on the plane wave assumption becomes increasingly limited. For vertical arrays with smaller apertures, under the far-field assumption, the difference in the angle of arrival of the sound source target across different array elements can be ignored; for each array element, the sound source can be considered to originate from the same angle of arrival. However, for large-aperture vertical arrays, when the far-field approximation does not hold true in the deep-sea direct sound zone, the angle of arrival of the sound source target relative to different array elements differs. If the steering vector constructed based on the plane wave assumption is continued for spatial power spectrum estimation, the different angles of arrival of the sound source across different array elements cause the sound source energy to be dispersed within a certain width of the angle of arrival range (from the angle of arrival of the shallowest element to the angle of arrival of the deepest element) in the spatial power spectrum estimation results, thus reducing the detection capability for weak targets. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem of reduced target detection performance of large-aperture vertical arrays under the traditional far-field plane wave assumption, and to provide a target detection method and system based on a deep-sea large-aperture vertical array, which utilizes the phase difference between each array element of the vertical array and the reference array element to construct a guiding vector.

[0005] To solve the above-mentioned technical problems, the target detection method based on a deep-sea large-aperture vertical array provided by the present invention includes:

[0006] Step 1: Receive the time-domain signal radiated by the target sound source by deploying a large-aperture vertical array on the seabed.

[0007] Step 2: Perform a Fast Fourier Transform on the time-domain signal received by each array element to obtain the corresponding signal spectrum;

[0008] Step 3: Calculate the steering vector based on the phase difference between the depth of each element of the large-aperture vertical array and the reference element; based on the steering vector, process the signal spectrum of different elements using the spatial power spectrum estimation method to obtain spatial power spectrum estimation results at different angles of arrival, so as to realize the detection of the target sound source.

[0009] As an improvement to the above method, the deployment depth of the large-aperture vertical array is 400-6000m, and the ocean depth D in the deep sea ranges from 1000-6000m.

[0010] As an improvement to the above method, the depths of each element in the large-aperture vertical array are d1,...,d1,... m ,...,d M Where d1 is the depth of the first array element, d m Let d be the depth of the m-th element. M Let f be the depth of the Mth element; the total number of elements in the large-aperture vertical array is M, and the sampling rate of the large-aperture vertical array is f. s The sampling rate f s The range is 100Hz to 40kHz.

[0011] As an improvement to the above method, in step 2, the time-domain signal received by the m-th array element undergoes a fast Fourier transform to obtain the signal at frequency f. l The signal spectrum at point x m (f l ); where l = 1, 2, ..., L, L is the number of frequency points used, f1 is the preset lower bound of the frequency range for spatial power spectrum estimation during target detection, f L This is a preset upper bound for the frequency range of the spatial power spectrum estimation during target detection.

[0012] As an improvement to the above method, the preset lower bound f1 of the target detection time-space power spectrum estimation frequency range is 0.1Hz to 3.5kHz, and the preset upper bound f1 of the target detection time-space power spectrum estimation frequency range is... L The range is 5Hz to 4kHz.

[0013] As an improvement to the above method, the spatial power spectrum estimation method includes: a conventional beamforming spatial power spectrum estimation method.

[0014] As an improvement to the above method, step 3 specifically includes:

[0015] Calculate at frequency point f l And angle θ k Beam output sound field B(θ) at the location k ):

[0016]

[0017] Wherein, the angle of arrival θ k A(θ) takes a value every 0.01° to 1° within the angular range of -90° to 90°; k ,f l X(f) is the steering vector calculated based on the phase difference between the depth of each element of the large-aperture vertical array and a reference element during beamforming, where the reference element is any element in the large-aperture vertical array; l () represents the target sound source radiated signal received by a large-aperture vertical array at frequency f l The spectral vector at the location; the superscript H denotes the conjugate transpose operator; f1 is the preset lower bound of the frequency range for spatial power spectrum estimation during target detection, f L This is a preset upper bound for the frequency range of spatial power spectrum estimation during target detection; where,

[0018]

[0019] For the angle of arrival θ greater than zero degrees k , propagation path length r m (θ k )for:

[0020]

[0021] Where, d ref For the depth of the reference array element, d m Let m be the depth of the m-th element;

[0022] For an angle of arrival θ equal to zero degrees k , propagation path length r m (θ k )for:

[0023] r m (θ k )=d m

[0024] For an angle of arrival θ less than zero degrees k , propagation path length r m (θ k )for:

[0025]

[0026] Where D represents ocean depth; c represents the speed of sound in the seawater at the center of the receiving array.

[0027] As an improvement to the above method, the reference array element is selected from the array element at the center of a large-aperture vertical array.

[0028] As an improvement to the above method, the target sound source radiation signal received by the large-aperture vertical array at frequency point f l The spectral vector X(f) at that location l )for:

[0029] X(f l )=[x1(f l ),x2(f l ),...,x m (f l ),...,x M (f l )] T

[0030] Where, x1(f l ) is the first array element at frequency point f l The signal spectrum at x2(f) l ) is the second array element at frequency point f l The signal spectrum at x; m (f l ) represents the m-th array element at frequency point f l The signal spectrum at x M (f l ) represents the frequency point f of the Mth array element. l The signal spectrum at the location; the total number of array elements of the large aperture vertical array is M; the superscript T indicates the transpose operator.

[0031] To achieve another objective of the present invention, the present invention also provides a target detection system based on a deep-sea large-aperture vertical array, comprising:

[0032] A large-aperture vertical array, placed on the bottom of the sea, is used to receive time-domain signals radiated by target sound sources.

[0033] The Fast Fourier Transform (FFT) module is used to perform Fast Fourier Transform on the time-domain signals received by each array element to obtain the corresponding signal spectrum; and

[0034] The estimation module is used to calculate the steering vector based on the phase difference between the depth of each element of the large-aperture vertical array and the reference element; and to process the signal spectrum of different elements based on the steering vector using the spatial power spectrum estimation method to obtain the spatial power spectrum estimation results at different angles of arrival, so as to realize the detection of the target sound source.

[0035] Compared to existing technologies, this invention proposes a target detection method and system based on a large-aperture vertical array in the deep sea. The system is configured as a large-aperture vertical acoustic array deployed near the seabed. This invention deploys the large-aperture vertical array near the seabed to receive the time-domain signal radiated by the target sound source. The detection of the target sound source is achieved through processing such as Fast Fourier Transform, steering vector calculation, and spatial power spectrum estimation. This invention selects a specific element of the vertical array as a phase reference point. Based on the assumption of constant sound speed at sea depth, the steering vector is calculated using geometric relationships, solving the problem of decreased target detection performance caused by different arrival angles of the sound source at different array elements in the traditional spatial power spectrum estimation method based on the plane wave assumption. This invention selects a specific element of the vertical array as a phase reference point. This method ignores the difference in sound speed at different depths of seawater. Based on the assumption that the sound speed of seawater from the surface to the seabed is constant in the deep sea, the phase difference between other array elements and the reference element is calculated using geometric relationships. Based on this phase difference, a corresponding steering vector is constructed, thereby solving the problem of different arrival angles of the sound source at different array elements and improving target detection performance. In addition, since a certain array element is selected as the reference array element to construct the steering vector, the target detection method and system proposed in this invention retain the channel response from the target sound source to the reference array element. Therefore, the target detection method and system proposed in this invention can also be further used for subsequent target position and marine environmental parameter inversion and other related work. Attached Figure Description

[0036] Figure 1 The seawater acoustic velocity profile and vertical array deployment depth used in the simulation experiment of this invention;

[0037] Figure 2(a) shows the motion trajectory of the sound source in the simulation experiment of this invention;

[0038] Figure 2(b) shows the sound source transmission and reception distance in the simulation experiment of this invention;

[0039] Figure 3(a) shows the spatial power spectrum estimation results of the target sound source obtained by conventional beamforming at all times in the simulation experiment with medium and high signal-to-noise ratio based on the plane wave assumption.

[0040] Figure 3(b) shows the spatial power spectrum estimation results of the target sound source obtained by conventional beamforming at all times in the simulation experiment with medium and high signal-to-noise ratio based on the method provided in this invention;

[0041] Figure 4(a) shows the spatial power spectrum estimation results of the target sound source obtained by conventional beamforming at all times in the simulation experiment at medium and low signal-to-noise ratio based on the plane wave assumption.

[0042] Figure 4(b) shows the spatial power spectrum estimation results of the target sound source obtained by conventional beamforming at all times in the simulation experiment with medium and low signal-to-noise ratio based on the method provided in this invention.

[0043] Figure 5The flowchart shows the target detection method based on a deep-sea large-aperture vertical array provided by this invention. Detailed Implementation

[0044] The technical solutions provided by the present invention will be further illustrated below with reference to the embodiments.

[0045] Example 1

[0046] This embodiment provides a target detection method based on a deep-sea large-aperture vertical array, including:

[0047] Step 1: Receive the time-domain signal radiated by the target sound source by deploying a large-aperture vertical array on the seabed.

[0048] Step 2: Perform a Fast Fourier Transform on the time-domain signal received by each array element to obtain the corresponding signal spectrum;

[0049] Step 3: Calculate the steering vector based on the phase difference between the depth of each element of the large-aperture vertical array and the reference element; based on the steering vector, process the signal spectrum of different elements using the spatial power spectrum estimation method to obtain spatial power spectrum estimation results at different angles of arrival, so as to realize the detection of the target sound source.

[0050] Specifically, the deployment depth of the large-aperture vertical array is 400-6000m, and the ocean depth D in the deep sea ranges from 1000-6000m.

[0051] Specifically, the depths of each element in the large-aperture vertical array are d1,...,d1,... m ,...,d M Where d1 is the depth of the first array element, d m Let d be the depth of the m-th element. M Let f be the depth of the Mth element; the total number of elements in the large-aperture vertical array is M, and the sampling rate of the large-aperture vertical array is f. s The sampling rate f s The range is 100Hz to 40kHz.

[0052] Specifically, in step 2, the time-domain signal received by the m-th array element undergoes a fast Fourier transform to obtain the signal at frequency f. l The signal spectrum at point x m (f l ); where l = 1, 2, ..., L, and L is the number of frequency points used. f1 is the preset lower bound of the frequency range for spatial power spectrum estimation during target detection, f L This is a preset upper bound for the frequency range of the spatial power spectrum estimation during target detection.

[0053] Specifically, the preset lower bound f1 of the target detection time-space power spectrum estimation frequency range is 0.1Hz to 3.5kHz, and the preset upper bound f1 of the target detection time-space power spectrum estimation frequency range is... L The range is 5Hz to 4kHz.

[0054] Specifically, the spatial power spectrum estimation method includes: conventional beamforming spatial power spectrum estimation method.

[0055] Specifically, step 3 includes:

[0056] Calculate at frequency point f l And angle θ k Beam output sound field B(θ) at the location k ):

[0057]

[0058] Wherein, the angle of arrival θ k A(θ) takes a value every 0.01° to 1° within the angular range of -90° to 90°; k ,f l X(f) is the steering vector calculated based on the phase difference between the depth of each element of the large-aperture vertical array and a reference element during beamforming, where the reference element is any element in the large-aperture vertical array; l () represents the target sound source radiated signal received by a large-aperture vertical array at frequency f l The spectral vector at the location; the superscript H denotes the conjugate transpose operator; f1 is the preset lower bound of the frequency range for spatial power spectrum estimation during target detection, f L This is a preset upper bound for the frequency range of spatial power spectrum estimation during target detection; where,

[0059]

[0060] For the angle of arrival θ greater than zero degrees k , propagation path length r m (θ k )for:

[0061]

[0062] Where, d ref For the depth of the reference array element, d m Let m be the depth of the m-th element;

[0063] For an angle of arrival θ equal to zero degrees k , propagation path length r m (θ k )for:

[0064] rm (θ k )=d m

[0065] For an angle of arrival θ less than zero degrees k , propagation path length r m (θ k )for:

[0066]

[0067] Where D represents ocean depth; c represents the speed of sound in the seawater at the center of the receiving array.

[0068] Specifically, the reference array element is selected from the array element located at the center of a large-aperture vertical array.

[0069] Specifically, the target sound source radiation signal received by the large-aperture vertical array at frequency point f l The spectral vector X(f) at that location l )for:

[0070] X(f l )=[x1(f l ),x2(f l ),...,x m (f l ),...,x M (f l )] T

[0071] Where, x1(f l ) is the first array element at frequency point f l The signal spectrum at x2(f) l ) is the second array element at frequency point f l The signal spectrum at x; m (f l ) represents the m-th array element at frequency point f l The signal spectrum at x M (f l ) represents the frequency point f of the Mth array element. l The signal spectrum at the location; the total number of array elements of the large aperture vertical array is M; the superscript T indicates the transpose operator.

[0072] The following example illustrates this method using a simulation experiment of underwater acoustic source radiation signals received by a deep-sea vertical array deployed near the seabed. The sea depth in the simulation experiment was 3000m, and the seawater sound velocity profile used in the simulation is shown in Figures 2(a) and 2(b). The receiving array was a 200-element synchronously spaced vertical linear array deployed near the seabed, with an array aperture of 1000m, an element spacing of 5m, and a center depth of approximately 2440m. The array deployment depth is shown in Figure 2(a). Figure 1The sound source depth was set to 200m. The sound source initially approached and then moved away from the receiving array. The transmission and reception distance initially decreased from 15km to 2.6km and then increased to 11.2km. Figure 2(a) shows the trajectory of the sound source target relative to the vertical array, and Figure 2(b) shows the transmission and reception distance information of the sound source target relative to the vertical array. The detection of the target sound source was achieved through processing such as Fast Fourier Transform, steering vector calculation, and spatial power spectrum estimation. Figure 5 As shown, the process consists of the following steps:

[0073] Step 1: A 200-yuan synchronous vertical linear array is deployed near the seabed to collect the time-domain signal p radiated by the target sound source. m (t), the depth of each element in the vertical array is increased from 1940m to 2940m.

[0074] Step 2: Perform a Fast Fourier Transform on the time-domain signal acquired by the vertical array element to obtain the frequency of the m-th element at frequency f. l The spectrum at x m (f l ), where l = 1, 2, ..., L, L is the number of frequency points used, f1 and f L These represent the lower and upper bounds of the frequency range selected for spatial power spectrum estimation during target detection, respectively. f1 ranges from 0.1 Hz to 3.5 kHz. L The range is 5Hz to 4kHz. In this embodiment, f1 and f L The values ​​are taken as 50Hz and 100Hz respectively. The target sound source radiated signal received by the vertical array at frequency point f l The spectral vector X(f) at that location l )for:

[0075] X(f l )=[x1(f l ),x2(f l ),...,x M (f l )] T

[0076] Wherein, the superscript T denotes the transpose operator;

[0077] Step 3: Calculate the spatial power spectrum of the vertical array at different angles using conventional beamforming and other spatial power spectrum estimation methods. Taking conventional beamforming as an example, the following formula is used to calculate the power spectrum at frequency f. l Angle θ k Beam output sound field B(θ) at the location k ):

[0078]

[0079] Wherein, the angle of arrival θk A value is taken every 0.01° to 1° within the angle range of -90° to 90°. In this embodiment, the angle interval is set to 0.2°; A(θ) k ,f l ) is the steering vector A(θ) used during beamforming. k ,f l ):

[0080]

[0081] For an angle of arrival θ equal to zero degrees k , propagation path length r m (θ k )=d m ;

[0082] For θ greater than zero degrees k Length of propagation path Where, d ref For the depth of the reference array element, in this embodiment the reference array element is selected as the array element at the center of the vertical array;

[0083] For θ less than zero degrees k Length of propagation path Where D represents the ocean depth, which is 3000m. c represents the speed of sound of seawater at the center of the receiving array, and the superscript H indicates the conjugate transpose operator.

[0084] Example 2

[0085] This embodiment provides a target detection system based on a deep-sea large-aperture vertical array, including:

[0086] A large-aperture vertical array, placed on the bottom of the sea, is used to receive time-domain signals radiated by target sound sources.

[0087] The Fast Fourier Transform (FFT) module is used to perform Fast Fourier Transform on the time-domain signals received by each array element to obtain the corresponding signal spectrum; and

[0088] The estimation module is used to calculate the steering vector based on the phase difference between the depth of each element of the large-aperture vertical array and the reference element; and to process the signal spectrum of different elements based on the steering vector using the spatial power spectrum estimation method to obtain the spatial power spectrum estimation results at different angles of arrival, so as to realize the detection of the target sound source.

[0089] Figure 3 shows the spatial power spectrum estimation results during the movement of the target sound source when the source level is high and the signal-to-noise ratio is high. Figure 3(a) shows the results based on the plane wave assumption, and Figure 3(b) shows the results of the proposed method. It can be seen that the maximum peak value in Figure 3(a) is 105.7 dB. Due to the difference in the angle of arrival of the sound source target relative to different array elements, for the spatial power spectrum estimation method based on the plane wave assumption under far-field conditions, the energy of the target sound source is dispersed within a certain width of the angle of arrival range in the spatial power spectrum estimation results, thus reducing the detection capability of the target sound source, including both direct waves and sea surface reflected waves. In contrast, the proposed method shown in Figure 3(b) has a maximum peak value of 109.9 dB, which can better achieve in-phase superposition detection of signals received by each array element of the vertical array. Furthermore, this method better preserves the channel response from the target sound source to the reference array element, and the trajectory of the angle of arrival changes corresponding to multiple paths such as direct waves, sea surface reflected waves, seabed reflected waves, and seabed-sea surface reflected waves is clearer in the spatial power spectrum estimation results. Figure 4 shows the spatial power spectrum estimation results during the target sound source's motion when the source level is low. Figure 4(a) shows the results based on the plane wave assumption, and Figure 4(b) shows the results of the proposed method. It can be seen that the traditional spatial power spectrum estimation method based on the plane wave assumption, as shown in Figure 4(a), does not exhibit a clear trajectory of the target sound source's angle of arrival during the entire target motion period. However, within the 20-45 minute timeframe, the trajectory of the target sound source's angle of arrival is clearly observed in the results of the proposed method, as shown in Figure 4(b), thus achieving the detection of the target sound source.

[0090] This invention innovatively proposes a target detection method and system based on a deep-sea large-aperture vertical array, using a specific array element as a phase reference point. This invention ignores the sound speed differences at different depths of seawater, assuming that the sound speed of seawater from the surface to the seabed is constant in the deep sea. It calculates the phase difference between other array elements and the reference element using geometric relationships, and constructs a corresponding steering vector based on this phase difference. This solves the problem of different arrival angles of sound sources at different array elements, thus improving target detection performance. Furthermore, because a specific array element is selected as the reference element to construct the steering vector, the target detection method and system proposed in this invention retain the channel response from the target sound source to the reference element. Therefore, the target detection method and system proposed in this invention can be further used for subsequent target location and marine environmental parameter inversion and other related work.

[0091] 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 target detection method based on a deep-sea large-aperture vertical array, comprising: Step 1: Receive the time-domain signal radiated by the target sound source by deploying a large-aperture vertical array on the seabed. Step 2: Perform a Fast Fourier Transform on the time-domain signal received by each array element to obtain the corresponding signal spectrum; Step 3: Calculate the steering vector based on the phase difference between the depth of each element of the large-aperture vertical array and the reference element; based on the steering vector, process the signal spectrum of different elements using the spatial power spectrum estimation method to obtain the spatial power spectrum estimation results under different angles of arrival, so as to realize the detection of the target sound source; The spatial power spectrum estimation method includes: a beamforming spatial power spectrum estimation method; Step 3 specifically includes: Calculate at frequency point f l And angle θ k Beam output sound field B(θ) at the location k ): Wherein, the angle of arrival θ k A(θ) takes a value every N degrees within the angle range of -90° to 90°, where N∈[0.01,1]; k ,f l X(f) is the steering vector calculated based on the phase difference between the depth of each element of the large-aperture vertical array and a reference element during beamforming, where the reference element is any element in the large-aperture vertical array; l () represents the target sound source radiated signal received by a large-aperture vertical array at frequency f l The spectral vector at the location; the superscript H denotes the conjugate transpose operator; f1 is the preset lower bound of the frequency range for spatial power spectrum estimation during target detection, f L This is a preset upper bound for the frequency range of spatial power spectrum estimation during target detection; where, For the angle of arrival θ greater than zero degrees k , propagation path length r m (θ k )for: Where, d ref For the depth of the reference array element, d m Let m be the depth of the m-th element; For an angle of arrival θ equal to zero degrees k , propagation path length r m (θ k )for: r m (i k )=d m For an angle of arrival θ less than zero degrees k , propagation path length r m (θ k )for: Where D represents ocean depth; c represents the speed of sound in the seawater at the center of the receiving array.

2. The target detection method based on a deep-sea large-aperture vertical array according to claim 1, characterized in that, The deployment depth of the large-aperture vertical array is 400m-6000m, and the ocean depth D ranges from 1000m to 6000m in the deep sea.

3. The target detection method based on a deep-sea large-aperture vertical array according to claim 1, characterized in that, The depths of each element in the large-aperture vertical array are d1,...,d1,... m ,...,d M ; Where d1 is the depth of the first array element, d m Let d be the depth of the m-th element. M Let f be the depth of the m-th element; the total number of elements in the large-aperture vertical array is M, and the sampling rate of the large-aperture vertical array is f. s The sampling rate f s The range is 100Hz to 40kHz.

4. The target detection method based on a deep-sea large-aperture vertical array according to claim 1, characterized in that, In step 2, the time-domain signal received by the m-th array element undergoes a Fast Fourier Transform to obtain the signal at frequency f. l The signal spectrum at point x m (f l ); where l = 1, 2, ..., L, L is the number of frequency points used, f1 is the preset lower bound of the frequency range for spatial power spectrum estimation during target detection, f L This is a preset upper bound for the frequency range of the spatial power spectrum estimation during target detection.

5. The target detection method based on a deep-sea large-aperture vertical array according to claim 4, characterized in that, The preset lower bound f1 of the target detection time-space power spectrum estimation frequency range is 0.1Hz to 3.5kHz, and the preset upper bound f1 of the target detection time-space power spectrum estimation frequency range is... L The range is 5Hz to 4kHz.

6. The target detection method based on a deep-sea large-aperture vertical array according to claim 1, characterized in that, The reference array element is selected from the element located at the center of a large-aperture vertical array.

7. The target detection method based on a deep-sea large-aperture vertical array according to claim 1, characterized in that, The target sound source radiation signal received by the large-aperture vertical array at frequency point f l The spectral vector X(f) at that location l )for: X(f l )=[x1(f l ),x2(f l ),...,x m (f l ),...,x M (f l )] T Where, x1(f l ) is the first array element at frequency point f l The signal spectrum at x2(f) l ) is the second array element at frequency point f l The signal spectrum at x; m (f l ) represents the m-th array element at frequency point f l The signal spectrum at x M (f l ) represents the frequency point f of the Mth array element. l The signal spectrum at the location; the total number of array elements of the large aperture vertical array is M; the superscript T indicates the transpose operator.

8. A target detection system based on a deep-sea large-aperture vertical array, comprising: A large-aperture vertical array, placed on the bottom of the sea, is used to receive time-domain signals radiated by target sound sources. The Fast Fourier Transform module is used to perform Fast Fourier Transform on the time-domain signals received by each array element to obtain the corresponding signal spectrum. and The estimation module is used to calculate the steering vector based on the phase difference between the depth of each element of the large-aperture vertical array and the reference element; and to process the signal spectrum of different elements based on the steering vector using the spatial power spectrum estimation method to obtain the spatial power spectrum estimation results at different angles of arrival, so as to realize the detection of the target sound source. The spatial power spectrum estimation method includes: a beamforming spatial power spectrum estimation method; The estimation module is specifically used for: Calculate at frequency point f l And angle θ k Beam output sound field B(θ) at the location k ): Wherein, the angle of arrival θ k A(θ) takes a value every N degrees within the angle range of -90° to 90°, where N∈[0.01,1]; k ,f l X(f) is the steering vector calculated based on the phase difference between the depth of each element of the large-aperture vertical array and a reference element during beamforming, where the reference element is any element in the large-aperture vertical array; l () represents the target sound source radiated signal received by a large-aperture vertical array at frequency f l The spectral vector at the location; the superscript H denotes the conjugate transpose operator; f1 is the preset lower bound of the frequency range for spatial power spectrum estimation during target detection, f L This is a preset upper bound for the frequency range of spatial power spectrum estimation during target detection; where, For the angle of arrival θ greater than zero degrees k , propagation path length r m (θ k )for: Where, d ref For the depth of the reference array element, d m Let m be the depth of the m-th element; For an angle of arrival θ equal to zero degrees k , propagation path length r m (θ k )for: r m (i k )=d m For an angle of arrival θ less than zero degrees k , propagation path length r m (θ k )for: Where D represents ocean depth; c represents the speed of sound in the seawater at the center of the receiving array.

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