A three-dimensional passive positioning method for low-frequency sound sources of a deep-sea small-aperture array

Abstract

The application discloses a kind of low-frequency sound source three-dimensional passive positioning methods of deep-sea small aperture array, belong to ocean engineering, underwater acoustic engineering, array signal processing and sonar technology technical field, comprising the following steps: S1, setting small aperture array initial parameter;S2, small aperture array carries out super directivity azimuth estimation;S3, using small aperture array carries out the matching field positioning of super directivity;S4, using S2 and S3 estimation result, using small aperture array beam output result estimation target depth;The application breaks through the limitation that conventional scalar array cannot simultaneously obtain target azimuth, distance and depth information under the condition of smaller array aperture, can simultaneously obtain target azimuth and distance information with smaller aperture, and obtains target depth information according to known target azimuth and distance information, and has good azimuth estimation performance, and is convenient to lay and recover, more widely applicable, and lower cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ocean engineering, underwater acoustic engineering, array signal processing and sonar technology, and particularly relates to a low-frequency sound source three-dimensional passive positioning method of a deep-sea small-aperture array. BACKGROUND

[0002] Low-frequency target passive positioning in a deep-sea environment is of great significance to the fields of ocean resource development and underwater acoustic detection. For low-frequency targets, a large-aperture vertical array is often used for range estimation and depth estimation, and a horizontal array is used for horizontal angle estimation. Due to the limitation of the array, in the case of only using a set of conventional scalar receiving array, the three types of information of the low-frequency sound source, i.e., azimuth, range and depth, cannot be obtained simultaneously.

[0003] In order to obtain the three-dimensional information of the passive sound source, a passive sound source three-dimensional positioning method suitable for deep-sea direct sound area environment is disclosed in Chinese Patent (Publication No. CN202211256111.X). This method is a distributed array, which requires that the distance between any two sensors is not less than 2 km, and the total number of sensors should not be less than 5. The distributed array has a large aperture, which makes it difficult to apply in practice.

[0004] As mentioned in the literature "Research on reliable acoustic path Physical properties and a source localization method, Chinese Physics B 21(12) 2012", a passive target positioning method suitable for reliable acoustic path is proposed. This method can only obtain the distance and depth information of the target, and cannot estimate the target azimuth. Moreover, it cannot accurately position the target under a small array aperture.

[0005] As mentioned in Chinese Patent (Publication No. CN202211256111.X), a passive moving sound source three-dimensional positioning method suitable for deep-sea direct sound area environment is disclosed. This method is only suitable for moving targets, and requires two sets of large-aperture horizontal receiving arrays located on the seabed. The method has low applicability.

[0006] As mentioned in Chinese Patent (Publication No. CN201210468673.0), a passive positioning method based on a single vector hydrophone is proposed. This method can only estimate the target azimuth and velocity, and the azimuth estimation can only use the sound pressure signal and horizontal velocity signal received by the single vector hydrophone. The azimuth estimation performance is poor.

[0007] A three-dimensional positioning method and device are provided in Chinese Patent (Publication No. CN202310501124.7), but the method only uses sound pressure signals and horizontal vibration velocity signals for target azimuth estimation, and the azimuth estimation performance is poor. Moreover, a large-aperture vector vertical array is used, which has high cost and is difficult to deploy and recover.

[0008] Therefore, there is a need for a deep-sea small-aperture array low-frequency sound source three-dimensional passive positioning method to solve the above problems. SUMMARY

[0009] The purpose of the present application is to provide a deep-sea small-aperture array low-frequency sound source three-dimensional passive positioning method to solve the problems raised in the background art.

[0010] To achieve the above purpose, the present application provides the following technical solution: a deep-sea small-aperture array low-frequency sound source three-dimensional passive positioning method, comprising the following steps:

[0011] S1, setting the initial parameters of the small-aperture array;

[0012] S2, the small-aperture array performs super-directivity azimuth estimation;

[0013] S3, the small-aperture array performs super-directivity matched field positioning;

[0014] S4, the small-aperture array estimates the target depth.

[0015] The method uses the super-directivity azimuth estimation method to obtain the horizontal angle estimation; then uses the super-directivity matched field positioning method to obtain the target distance information; given the target horizontal angle and pitch angle estimation value, the received signal is beam output to improve the signal-to-noise ratio of the received signal, and the single-channel beam output result is extracted for cepstrum processing to estimate the time delay difference, which is matched with the ray model simulation multi-path arrival time delay difference to obtain the target depth value.

[0016] As a preferred scheme, in "S1", the small-aperture array pattern is set, the number of array elements M, the hydrophone is non-directional, and the array flow vector is set and , wherein , , is the pitch angle, is the horizontal angle, , represents the wavelength of the incident plane wave, is the coordinate position of the mth array element; it is assumed is the N snapshots of the plane wave signal incident from the direction The actual received data is , wherein is the random noise unrelated to the signal.

[0017] As a preferred scheme, in "S2", the sound source positioning is performed by using the super-directivity direction estimation method, and for the super-directivity direction estimation method, the distortionless response constraint of the received data output is minimized as , wherein is a weight vector, is an array received data sample covariance matrix, and is a direction spectrum of the super-directivity direction estimation method, a peak value of the direction spectrum is an angle estimation value of the low-frequency passive sound source, and the super-directivity direction estimation method is used to simultaneously estimate and .

[0018] As a preferred scheme, in "S3", the target ranging is performed by using the super-directivity matched field positioning method, and the target position is set as wherein z is a target distance from the sea surface depth, r is a target distance from the array in the horizontal direction, and a multipath arrival angle of the signal is wherein is determined by the environment and can be calculated by using the ray theory, the in "S2" is used for calculation, and an elevation angle estimation value is obtained. The target elevation angle is estimated, and the estimation result is matched with , and a most suitable result is the target position.

[0019] As a preferred scheme, in "S3", the matched field positioning of the super-directivity is performed by using the small aperture array, after the target horizontal angle estimation value is obtained, the array manifold vector is optimized, and the horizontal angle is the estimation result of "S2"; the multipath arrival structure is obtained by using the ray model, the elevation angle estimation value of the super-directivity direction estimation is matched with the multipath arrival angle calculated by using the ray model, a two-dimensional fuzzy plane of the depth and the distance is obtained, and a bright spot is the target positioning estimation result.

[0020] As a preferred scheme, in "S4", the multipath arrival structure is obtained by using the ray model simulation, the target horizontal angle and the distance information are known, that is, the target horizontal angle and the elevation angle are known, the received signal is subjected to beam output, the signal noise ratio of the received signal is improved, and the error of the depth estimation of the small aperture array is reduced, and the beam output result is , the beam output result of the center element of the small aperture receiving array is selected to obtain the time delay difference by using the cepstrum, and the time delay difference obtained by using the simulation result is matched, and the depth corresponding to the minimum value sequence number is the depth estimation value.

[0021] Compared with the prior art, the present application has the beneficial effects of:

[0022] The present application breaks through the limitation that the conventional scalar array cannot simultaneously acquire the target azimuth, distance and depth information under the condition of smaller array aperture, can simultaneously acquire the target azimuth and distance information with smaller aperture, acquires the target depth information according to the known target azimuth and distance information, has better azimuth estimation performance, is convenient for laying and recovering, has wider application range and lower cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flow chart of the three-dimensional passive positioning method of the small-aperture array of the present application;

[0024] Figure 2 The three-dimensional view and top view of the five-layer cylindrical array array pattern structure of the present application

[0025] Figure 3 The azimuth and distance estimation result graph of the present application;

[0026] Figure 4 The ranging schematic diagram of the super-directivity matching field positioning method of the present application;

[0027] Figure 5 The beam output signal spectrum graph of the present application;

[0028] Figure 6 The beam output cepstrum result graph of the present application;

[0029] Figure 7 The depth estimation graph of the present application. DETAILED DESCRIPTION

[0030] The present application will be further described below in combination with examples.

[0031] The following examples are used to illustrate the present application, but cannot be used to limit the protection scope of the present application. The conditions in the examples can be further adjusted according to specific conditions, and the simple improvement of the method of the present application under the concept of the present application belongs to the protection scope of the present application.

[0032] Please refer to Figures 1-7 The present application provides a three-dimensional passive positioning method of a low-frequency sound source of a small-aperture array in deep sea, comprising the following steps:

[0033] S1, setting the initial parameters of the small-aperture array;

[0034] Setting the array pattern of the small-aperture array, a small-aperture cylindrical array is simulated, the number of array elements is From top to bottom, it is the first to fifth layer, 8 hydrophones are uniformly arranged in each layer, the diameter is 6 meters, the interval between layers is 1 meter, and the array element position coordinates are as follows Figure 2As shown; set the array manifold vector In the formula , , The pitch angle, It is a horizontal angle. , This represents the wavelength of the incident plane wave. Let m be the coordinate position of the m-th array element; assume From For N snapshots of a plane wave signal incident in a specific direction, the actual received data is: ,in The signal-to-noise ratio of the received data is 30dB, which is random noise unrelated to the signal.

[0035] Ray model simulation conditions: Using the BELLHOP acoustic toolbox, distance meshes were generated. (Unit: km) Delineation of sound source depth grid (Unit: m), receiving array depth 4200m, sea depth 5000m, using Munk sound velocity profile, the sound velocity of the water near the water-sediment interface is 1567m / s, the sediment layer thickness is 50m, the seabed is composed of sediment layer and basement layer, the signal is 250Hz line spectrum, the sound source depth is 50m, and the distance between the sound source and the receiving array is 7km.

[0036] S2. Small aperture array for super-directional azimuth estimation;

[0037] Sound source localization is performed using a super-directional azimuth estimation method. For this method, the constraint of minimizing the distortion-free response of the received data output is: and ,in For weighted vectors, The sampled covariance matrix of the array received data is given by... The azimuth spectrum of the super-directional azimuth estimation method is: The azimuth spectrum peak value is the angle estimate of the low-frequency passive sound source. A super-directivity azimuth estimation method is used for... Make an estimate.

[0038] S3. Using a small-aperture array for super-directional matching field localization, after obtaining the target horizontal angle estimate, optimize the array manifold vector. The horizontal angle... The estimated result for "S2" is given; the multipath arrival structure is obtained using Bellhop simulation, and the target range is measured using a super-directional matched field localization method, setting the target position. Where z is the target's depth above the sea surface, r is the target's horizontal distance from the array, and the signal's multipath angle of arrival is... ,in Determined by the environment, can be calculated by ray theory, using the "S2" in Calculate to get the pitch angle estimate , the target pitch angle is estimated, and the estimation result Match with The best matching result is the target position , define the fuzzy plane of the super-directivity matching field positioning method and perform normalization processing: At this time, draw the fuzzy plane of distance and depth.

[0039] S4, estimate the target depth using a small aperture array;

[0040] Obtain the multipath arrival structure through the ray model of "S3", extract the time delay information of the direct wave and the first sea surface reflection wave respectively, and obtain the time delay difference matrix of the direct wave and the first sea surface reflection wave of the center array element of the receiving array under different sound source depth conditions , wherein R represents the distance grid number, D represents the sound source depth grid number, and the distance estimate value is selected according to the known target horizontal angle and distance at this time The time delay difference of the direct wave and the first sea surface reflection wave of the array element , the array acquisition signal is subjected to beam output, and the beam output result is , the beam output result of the center array element of the receiving array is selected for cepstrum analysis, and the cepstrum is , the corresponding peak value in the cepstrum is found, which is the time delay of the corresponding multipath arrival sound line, and the time delay difference is calculated Match with the simulation result, minimize the measured value and the calculated value, and the minimum value corresponding to the average of multiple cycles is the depth estimate value: .

[0041] The working principle and use process of the application are as follows: first, set the initial parameters of the small aperture array, then perform super-directivity azimuth estimation and matching field positioning using the small aperture array in turn, finally estimate the target depth using the small aperture array, obtain the multipath arrival structure using BELLHOP simulation, and know the target horizontal angle and distance information, that is, the target horizontal angle and pitch angle, improve the signal-to-noise ratio of the received signal by performing beam output on the received signal, reduce the error of the small aperture array depth estimation, and the beam output result is , the beam output result of the center array element of the small aperture receiving array is selected for cepstrum to obtain the time delay difference Match the time delay difference obtained from the simulation result, and the depth corresponding to the minimum value number is the depth estimate value.

[0042] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A method for three-dimensional passive localization of low-frequency sound sources of a deep-sea small-aperture array, characterized in that: The method comprises the following steps: S1, setting initial parameters of a small-aperture array; Set small aperture array, array element number M, hydrophone nondirectional, set array flow vector and , wherein , , is the pitch angle, is the horizontal angle, , represents the wavelength of the incident plane wave, is the coordinate position of the mth array element; S2, performing super-directivity direction estimation by the small-aperture array; The super-directive DOA estimation method is used for sound source positioning. For the super-directive DOA estimation method, a minimum distortionless response constraint of received data output is , , wherein is a weighting vector, is an array received data sample covariance matrix, and is a super-directive DOA estimation method, and a DOA spectrum of the super-directive DOA estimation method is , a peak value of the DOA spectrum is an angle estimation value of a low-frequency passive sound source, and the super-directive DOA estimation method is used for simultaneously estimating and . S3, performing super-directivity matched field positioning by the small-aperture array; The target distance is measured by using the super-directivity matched field positioning method, and the target position is set as Wherein z is the target distance from the sea surface depth, r is the horizontal distance of the target from the array, and the multi-path arrival angle of the signal is Wherein Determined by the environment, it can be calculated by ray theory, and the is calculated to obtain the estimated value of the pitch angle The target pitch angle is estimated, and the estimation result is matched with , and the best matching result is the target position ; The horizontal angle estimation value of the target is obtained by using the small aperture array to perform the matched field localization of the super-directivity, and the array flow vector is optimized The multi-path arrival structure is obtained by using the ray model, the elevation angle estimation value of the super-directivity azimuth estimation is matched with the multi-path arrival angle calculated by the ray model, a two-dimensional fuzzy plane of depth and distance is obtained, and the bright spot is the target positioning estimation result. S4, estimating target depth by the small-aperture array; The multi-path arrival structure is simulated by using the ray model. The horizontal angle and distance information of the target are known, that is, the horizontal angle and the pitch angle of the target are known. The signal-to-noise ratio of the received signal is improved by performing beam output on the received signal, and the error of the small-aperture array depth estimation is reduced. At this time, the beam output result is . The beam output result of the central array element of the small-aperture receiving array is selected to obtain the time delay difference by performing cepstrum. The time delay difference obtained by the simulation result is matched, and the minimum value sequence number corresponds to the depth estimation value.

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