CN-121995502-A - Magnetic anomaly signal detection method, system, equipment and medium

CN121995502ACN 121995502 ACN121995502 ACN 121995502ACN-121995502-A

Abstract

The invention relates to the technical field of magnetic detection and discloses a magnetic anomaly signal detection method, a magnetic anomaly signal detection system, magnetic anomaly signal detection equipment and a magnetic anomaly signal detection medium. The method comprises the steps of obtaining a magnetic anomaly field of a target observation area, obtaining magnetic anomaly fields of standard magnetic dipoles with magnetic moments in the directions of x, y and z in the direction of a geomagnetic field of the target observation area as two-dimensional scalar magnetic anomaly fields, vectorizing the three two-dimensional scalar magnetic anomaly fields, forming a template matrix according to the array arrangement, carrying out matrix decomposition on the template matrix to obtain an orthogonal base matrix, constructing an orthogonal signal subspace of the magnetic dipoles according to the orthogonal base matrix, projecting the magnetic anomaly fields of the target observation area to the orthogonal signal subspace, and carrying out magnetic target detection according to the energy distribution condition of the magnetic anomaly fields of the target observation area in the orthogonal signal subspace. The invention can realize magnetic anomaly detection under low signal-to-noise ratio without target depth priori information and a large amount of training data.

Inventors

MU YAXIN
ZHANG JINGWEI

Assignees

北京信息科技大学

Dates

Publication Date: 20260508
Application Date: 20260210

Claims (10)

1. A method for detecting a magnetic anomaly signal, the method comprising: acquiring a magnetic abnormal field of a target observation area; Acquiring magnetic anomaly fields of three standard magnetic dipoles with magnetic moments along x, y and z directions in the geomagnetic field direction of a target observation area as two-dimensional scalar magnetic anomaly fields; Vectorizing three two-dimensional scalar magnetic anomaly fields, then arranging the three two-dimensional scalar magnetic anomaly fields according to columns to form a template matrix, and carrying out matrix decomposition on the template matrix to obtain an orthogonal base matrix; constructing an orthogonal signal subspace of the magnetic dipole according to the orthogonal base matrix, and projecting a magnetic abnormal field of the target observation area to the orthogonal signal subspace; And carrying out magnetic target detection according to the energy distribution condition of the magnetic abnormal field of the target observation area in the orthogonal signal subspace.
2. The method of claim 1, wherein the two-dimensional scalar magnetic anomaly field is a standard magnetic dipole having three magnetic moments along x, y, and z directions, respectively, a magnetic anomaly field in a geomagnetic field direction of an observation plane within a target observation area; Wherein, the magnetic moment of the standard magnetic dipole is 1, and the depth is any depth in the underground space; the size of the observation plane is 2 times of the vertical height of the observation plane and the standard magnetic dipole.
3. The method for detecting a magnetic anomaly signal according to claim 1, wherein the matrix decomposition method of the template matrix is QR decomposition with column selection principal elements or singular value decomposition SVD.
4. The method of claim 1, wherein the orthogonal signal subspace of the magnetic dipole is constructed by the following formula: ; projecting the magnetic anomaly field of the target observation region into the orthogonal signal subspace by the following formula: ; in the formula, Is an orthogonal base matrix which is used for the data processing, For the orthogonal signal subspace, For a magnetic anomaly field of the target observation region, The energy distribution of the magnetic anomaly field in the orthogonal signal subspace.
5. The method for detecting a magnetic anomaly signal according to claim 1, wherein the detecting a magnetic anomaly field according to an energy distribution of a magnetic anomaly field of a target observation region in an orthogonal signal subspace comprises: According to the energy distribution condition of the magnetic abnormal field of the target observation area in the orthogonal signal subspace, extracting an area of which the energy exceeds a preset energy threshold value in the target observation area by a local maximum detection method; and detecting the magnetic target according to the region of which the energy exceeds the preset energy threshold value in the target observation region.
6. The method of claim 5, wherein the local maxima detection method uses a non-maxima suppression algorithm with 8 neighborhoods or windows greater than 8 neighborhoods.
7. The method of claim 2, wherein projecting the magnetic anomaly field of the target observation region into the orthogonal signal subspace comprises: Based on a sliding window method, the magnetic abnormal field of the target observation area is projected to the orthogonal signal subspace.
8. A magnetic anomaly signal detection system, the system comprising: The first magnetic field acquisition module is used for acquiring a magnetic abnormal field of the target observation area; the second magnetic field acquisition module is used for acquiring magnetic anomaly fields of three standard magnetic dipoles with magnetic moments along the x, y and z directions in the geomagnetic field direction of the target observation area respectively, and the magnetic anomaly fields are used as two-dimensional scalar magnetic anomaly fields; The matrix construction and decomposition module is used for vectorizing the three two-dimensional scalar magnetic anomaly fields, forming a template matrix according to the arrangement of the columns, and carrying out matrix decomposition on the template matrix to obtain an orthogonal base matrix; the first magnetic field projection module is used for constructing an orthogonal signal subspace of the magnetic dipole according to the orthogonal base matrix and projecting a magnetic abnormal field of the target observation area to the orthogonal signal subspace; And the magnetic target detection module is used for detecting the magnetic target according to the energy distribution condition of the magnetic abnormal field signal subspace of the target observation area.
9. A computer device comprising at least one processor and a memory communicatively coupled to the at least one processor, wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the magnetic anomaly signal detection method of any one of claims 1 to 7.
10. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the magnetic anomaly signal detection method according to any one of claims 1 to 7.

Description

Magnetic anomaly signal detection method, system, equipment and medium Technical Field The present invention relates to the field of magnetic detection technology, and in particular, to a method, a system, an apparatus, and a medium for detecting a magnetic anomaly signal. Background Magnetic anomaly detection is one of the important means of near-surface target detection, and has the advantages of rapid detection and passive detection. In an actual test, a magnetic anomaly signal generated by a target is often affected by geomagnetic field fluctuation, surrounding environment magnetic noise, carrier platform interference and other factors, so that the magnetic anomaly signal generated by the target is buried in a noise signal. The magnetic anomaly signal detection capability under low signal-to-noise ratio can improve the recognition distance and precision of the deeply buried and small ferromagnetic targets, and breaks through the depth bottleneck of the traditional magnetic method detection. The existing magnetic anomaly signal detection methods are divided into two main types, namely detection methods based on signal processing and detection methods based on deep learning. Detection methods based on signal processing, such as 1D/2D quadrature basis filtering (Orthogonal Basis Filtering, OBF) and minimum entropy filters (minimum entropy detector, MED), require the depth of the magnetic target as a priori information to design the filter, and if the designed filter depth does not match the actual target depth, serious signal distortion or omission can result. The method for detecting the magnetic anomaly signals based on deep learning mainly comprises the steps of detecting whether target magnetic anomaly signals exist or not through supervision training data, wherein a common network architecture is ResNet, CNN and the like. Disclosure of Invention The invention aims to provide a magnetic anomaly signal detection method, a system, equipment and a medium, which can solve the technical problems. The embodiment of the invention provides a magnetic anomaly signal detection method, which comprises the following steps: acquiring a magnetic abnormal field of a target observation area; Acquiring magnetic anomaly fields of three standard magnetic dipoles with magnetic moments along x, y and z directions in the geomagnetic field direction of a target observation area as two-dimensional scalar magnetic anomaly fields; Vectorizing three two-dimensional scalar magnetic anomaly fields, then arranging the three two-dimensional scalar magnetic anomaly fields according to columns to form a template matrix, and carrying out matrix decomposition on the template matrix to obtain an orthogonal base matrix; constructing an orthogonal signal subspace of the magnetic dipole according to the orthogonal base matrix, and projecting a magnetic abnormal field of the target observation area to the orthogonal signal subspace; And carrying out magnetic target detection according to the energy distribution condition of the magnetic abnormal field of the target observation area in the orthogonal signal subspace. Further, the two-dimensional scalar magnetic anomaly field is a standard magnetic dipole with three magnetic moments along the x, y and z directions respectively, and is a magnetic anomaly field in the geomagnetic field direction of an observation plane in the target observation area; Wherein, the magnetic moment of the standard magnetic dipole is 1, and the depth is any depth in the underground space; the size of the observation plane is 2 times of the vertical height of the observation plane and the standard magnetic dipole. Further, the matrix decomposition method of the template matrix is QR decomposition or singular value decomposition SVD with column selection principal elements. Further, the orthogonal signal subspace of the magnetic dipole is constructed by the following formula: ; projecting the magnetic anomaly field of the target observation region into the orthogonal signal subspace by the following formula: ; in the formula, Is an orthogonal base matrix which is used for the data processing,For the orthogonal signal subspace,For a magnetic anomaly field of the target observation region,The energy distribution of the magnetic anomaly field in the orthogonal signal subspace. Further, the detecting the magnetic target according to the energy distribution of the magnetic abnormal field of the target observation area in the orthogonal signal subspace includes: According to the energy distribution condition of the magnetic abnormal field of the target observation area in the orthogonal signal subspace, extracting an area of which the energy exceeds a preset energy threshold value in the target observation area by a local maximum detection method; and detecting the magnetic target according to the region of which the energy exceeds the preset energy threshold value in the target observation region. Further, the local maximu