CN-121978618-A - Underwater target two-dimensional direction finding method and device and computing equipment

CN121978618ACN 121978618 ACN121978618 ACN 121978618ACN-121978618-A

Abstract

The application relates to the technical field of signal processing and provides a two-dimensional direction finding method for an underwater target, which comprises the steps of adopting a two-dimensional area array model to receive an incident signal in a sonar detection area, wherein the two-dimensional area array model comprises a three-dimensional array consisting of The method comprises the steps of dividing a two-dimensional area array model into a plurality of subarrays, wherein each subarray of the L subarrays comprises The method comprises the steps of receiving array elements, respectively eliminating uncorrelated noise components of incident signals of the L subarrays to obtain beams of each subarray in the L subarrays, wherein the beams of each subarray are non-uniform diagonal load shedding minimum variance undistorted response results, carrying out overlapped subarray space smoothing on the beams of each subarray in the L subarrays to estimate azimuth angle and pitch angle of an underwater target, and determining the space azimuth of the underwater target. According to the method, incoherent noise components are effectively eliminated, the anti-noise performance of the algorithm is obviously improved, and the estimation precision and resolution of the target two-dimensional angle are improved.

Inventors

HAO CHENGPENG
YAN LINJIE
SUN JIARUI

Assignees

中国科学院声学研究所

Dates

Publication Date: 20260505
Application Date: 20260112

Claims (10)

1. A method for two-dimensional direction finding of an underwater target, the method comprising: Receiving an incident signal in a sonar detection area by adopting a two-dimensional area array model, wherein the two-dimensional area array model comprises a three-dimensional array consisting of The incidence signal comprises echo signals and noise components of an underwater target; dividing the two-dimensional area array model into L subarrays, wherein each subarray of the L subarrays comprises The value of L is at least 4; Respectively eliminating noise components of the L subarray incident signals to obtain beams of each subarray in the L subarrays, wherein the beams of each subarray are non-uniform diagonal load shedding minimum variance undistorted response (IDU-MVDR) results; and carrying out overlapped subarray space smoothing solving on wave beams of each subarray in the L subarrays to estimate azimuth angle and pitch angle of the underwater target, and determining the space azimuth of the underwater target.
2. The method of claim 1, wherein receiving the incident signal in the sonar detection area using a two-dimensional area array model comprises: Determining a guide vector a according to the wave path difference of the incident signals received by two adjacent receiving array elements , ) The guiding vector a is # , ) The method comprises the following steps: Wherein, the 、 Representing the azimuth and pitch angles of the incident signal, Indicating the received signal wave path difference of two adjacent array elements, Is the signal wavelength; performing time-frequency conversion, expectation and conjugate transposition operation according to the incident signal steering vector to obtain the incident signal covariance matrix, wherein the incident signal covariance matrix is as follows: Wherein, the 、 Representing the desired and conjugate transpose operations, respectively; for a received signal matrix: Wherein the method comprises the steps of Represent the first Frequency domain signal of each array element.
3. The method of claim 1 or 2, wherein estimating azimuth and pitch angles of the underwater target from the overlapping subarray spatial smoothing solution of the plurality of subarrays comprises: solving the load reduction amount of each array element of each subarray in the L subarrays by adopting an uneven diagonal load reduction minimum variance undistorted response (IDU-MVDR) method; According to the first Covariance matrix of sub-array received signal And (d) The load reduction amount of each array element on each subarray is determined and the load reduction is carried out Covariance matrix of each subarray The method comprises the following steps: Wherein, the Is the first On the sub-array The load of each array element is reduced, And the first step The load shedding amount of each array element comprises Uncorrelated noise components on individual array elements; Expressed in terms of Is a diagonal matrix of diagonal elements.
4. The method of claim 3, wherein solving for the load shedding amount of each element of each of the L subarrays using an uneven diagonal load shedding minimum variance distortion free response (IDU-MVDR) method comprises: and enabling the minimum eigenvalue of the covariance matrix after load shedding to be a positive value based on constraint conditions, wherein the constraint conditions are as follows: Wherein, the Is a matrix of units which is a matrix of units, The minimum eigenvalue of the covariance matrix; Representing covariance matrix Middle (f) The number of diagonal elements is one, Is a load shedding coefficient; And maximizing the total load shedding amount: 。 and solving the constraint condition and the maximum load shedding total amount to obtain the load shedding amount of each array element.
5. The method of claim 3, wherein the separately canceling uncorrelated noise components of the L subarray incident signals to obtain beams for each of the L subarrays comprises: According to the covariance matrix after the diagonal load shedding Determining the first subarray of the L subarrays Wave beam of individual subarrays The method comprises the following steps: 。 Wherein, the The azimuth angle and the pitch angle in the two-dimensional area array are determined; Is the first Frequency domain signals of each subarray are input; For the beam scan vector: 。
6. The method of claim 5, wherein the beams of the L subarrays comprise a first subarray beam, a second subarray beam, a third subarray beam, and a fourth subarray beam, the estimating azimuth and elevation angles of the underwater target from the overlapping subarray spatial smoothing solutions of the plurality of subarrays further comprising: The planar array ultrasonic beam comprises a three-ultrasonic beam and a two-four-ultrasonic beam, wherein the three-ultrasonic beam is determined according to the sum beam and the difference beam of the first subarray beam and the third subarray beam, and the two-four-ultrasonic beam is determined according to the sum beam and the difference beam of the first subarray beam and the third subarray beam; And adjusting the main lobe width and the side lobe height of the planar array ultrasonic beam based on the ultrasonic beam index and the split beam weight coefficient of the beam.
7. The method of claim 6, wherein estimating azimuth and pitch angles of the underwater target from the planar array spatial smoothing solution of the plurality of sub-arrays further comprises: determining a space weighting coefficient according to the planar array ultrasonic beam; Multiplying the spatial weighting coefficients by the beams of the L subarrays respectively to obtain weighted beams with phase information; And estimating azimuth angle and pitch angle of the underwater target according to the weighted beam with the phase information.
8. An underwater target two-dimensional direction finding device, the device comprising: A scene modeling module for receiving an incident signal in a sonar detection area by adopting a two-dimensional area array model, wherein the two-dimensional area array model comprises a three-dimensional array consisting of The incidence signal comprises echo signals and noise components of an underwater target; The subarray dividing module is used for dividing the two-dimensional area array model into L subarrays, wherein each subarray in the L subarrays comprises The value of L is at least 4; The denoising module is used for respectively eliminating uncorrelated noise components of the L subarray incident signals to obtain beams of each subarray in the L subarrays, wherein the beams of each subarray are non-uniform diagonal load reduction minimum variance undistorted response (IDU-MVDR) results; And the positioning module is used for carrying out overlapped subarray space smoothing solution on wave beams of each subarray in the L subarrays to estimate the azimuth angle and the pitch angle of the underwater target, and determining the space azimuth of the underwater target.
9. A computing device comprising at least one memory for storing a program, and at least one processor for executing the program stored in the memory, the processor for performing the method of any of claims 1-8 when the program stored in the memory is executed.
10. A computer readable storage medium storing a computer program which, when run on a processor, causes the processor to perform the method of any one of claims 1-8.

Description

Underwater target two-dimensional direction finding method and device and computing equipment Technical Field The application relates to the technical field of underwater detection, in particular to a two-dimensional direction finding method, a device and computing equipment for an underwater target. Background Acoustic target localization continues to raise a high degree of interest in the underwater acoustic community as a core technology in the field of underwater exploration. Unmanned observation platforms such as autonomous underwater vehicles are of great importance to the estimation capability of position parameters such as azimuth angles, radial distances and the like of non-cooperative targets. The method is not only a basis for realizing target position sensing and continuous monitoring, but also provides necessary information support for effective striking or reasonable avoidance of subsequent implementation. One common direction finding method is to process the array received signal by beam forming technology and determine the direction of arrival of the target based on the spectral peak search result. On the basis, the matching signals are utilized to perform pulse compression processing on the wave beams, and target distance estimation is achieved. Therefore, a high-resolution target direction finding method capable of retaining phase information to realize matched filtering is a guarantee of realizing accurate target positioning. The super beam forming technology is initially used for a radar beam pattern azimuth searching system, can effectively reduce the width of a main lobe, inhibit side lobes and further realize accurate orientation, and is widely applied to the field of underwater sound detection. The conventional super-beam forming method mainly has three limitations that 1) the conventional super-beam forming method is mainly based on a uniform linear array model, so that the conventional super-beam forming method does not have pitch angle estimation capability and cannot determine the spatial orientation of a target, and 2) nonlinear summation operation is introduced in the algorithm processing process, so that the phase and frequency characteristics of beam signals are distorted. Therefore, the output result is only suitable for energy detection scenes, but cannot support the fine processing of matched filtering, spectrum analysis and the like, and 3) the method has poor anti-noise interference capability, and the matrix inversion operation in the processing process causes the problem of poor algorithm robustness. Disclosure of Invention In order to realize high-precision two-dimensional direction finding and improve the noise immunity of an algorithm, the patent focuses on the defect of a conventional ultrasonic beam method in the target two-dimensional direction finding process and provides an underwater target two-dimensional direction finding method based on improved ultrasonic beam forming. In a first aspect, an embodiment of the present application provides a two-dimensional direction-finding method for an underwater target, including receiving an incident signal in a sonar detection area by using a two-dimensional area array model, where the two-dimensional area array model includes a three-dimensional array ofThe method comprises the steps of dividing a two-dimensional area array model into L subarrays, wherein each subarray in the L subarrays comprisesThe method comprises the steps of receiving array elements, wherein the value of L is at least 4, eliminating uncorrelated noise components of incident signals of the L subarrays to obtain beams of each subarray in the L subarrays, enabling the beams of each subarray to be a non-uniform diagonal load shedding minimum variance undistorted response (IDU-MVDR) result, carrying out overlapped subarray space smoothing on the beams of each subarray in the L subarrays to estimate azimuth angle and pitch angle of an underwater target, and determining the space azimuth of the underwater target. In some possible embodiments, the two-dimensional area array model is used for receiving the incident signals in the sonar detection area, and the method comprises the steps of determining a guide vector a according to the wave path difference of the incident signals received by two adjacent receiving array elements, ) Guide vector a #, ) The method comprises the following steps: Wherein, the 、Representing the azimuth and elevation angles of the incident signal,Indicating the received signal wave path difference of two adjacent array elements,Performing time-frequency conversion, expected and conjugate transposition operation according to an incident signal guiding vector to obtain an incident signal covariance matrix, wherein the incident signal covariance matrix is as follows: Wherein, the 、Representing the desired and conjugate transpose operations, respectively; for a received signal matrix: Wherein the method comprises the steps of Repres