196 results about "Magnetic gradient" patented technology

The invention relates to the technical field of geophysics, and particularly discloses a comprehensive inversion method and system based on bidirectional magnetic susceptibility weighted constraint, and the method comprises the steps: dividing an underground three-dimensional space, and building two different cuboid models; determining a total magnetic field observed on the ground and gradient anomaly thereof based on the observation point coordinates and the cuboid model position, and establishing a kernel function matrix; determining an inversion objective function reflecting the relationship between the total magnetic field and the gradient anomaly thereof and the physical property parameters; adding the bidirectional magnetic susceptibility weighted constraint function into an inversion objective function; the optimal solution of the comprehensive inversion target function is solved based on the conjugate gradient method, the high-level resolution capability of the magnetic gradient data and the deep detection advantage of the total magnetic field data are fused, the precision of fine depiction of the superficial anomalous body boundary and the reconstruction precision of the deep field source structure are remarkably improved, a vector cross multiplication regularization constraint mechanism is introduced, and the method has the advantages of high resolution and high resolution. The inversion multiplicity under the complex geological condition is greatly inhibited, and the reliability of the model result and the geological rationality are enhanced.

A magnetic gradiometer can be used in systems or methods for nondestructive testing, even when the material being tested is weakly magnetic. The magnetic gradiometer can include a printed circuit board (PCB) comprising a first end and a second end separated by a base length; an excitation coil encircling at least a portion of the PCB and configured to deliver an alternating current (AC) to generate an excitation magnetic field; and a differential sensor. The differential sensor can include a reference magnetic tunneling junction in magnetic vortex state (vortex MTJ) sensor array at the first end to generate a voltage based on the excitation magnetic field; and a signal vortex MTJ sensor array at the second end to generate another voltage based on the excitation magnetic field due to a composition of the measurement target. The second end of the PCB can be oriented towards the measurement target.

The invention relates to the technical field of geomagnetic vector measurement, and particularly provides a magnetic target intelligent positioning method and system based on a magnetic gradient tensor time sequence, and the method comprises the steps: employing a plurality of magnetic sensors to form a cube magnetic sensor array model; constructing magnetic gradient tensor sequence data based on the distance from the original point to the magnetic target represented by the magnetic gradient tensors of any two surfaces in the magnetic sensor array model; and adopting an LSTM neural network positioning model and taking the magnetic gradient tensor sequence data as model input to obtain a magnetic target position. The distance between the magnetic target and the original point is represented by the magnetic gradient tensor, so that the influence of the magnetic vector of the geomagnetic field on the determination of the position of the magnetic target can be reduced. According to the LSTM neural network magnetic target positioning model designed by the invention, key information of different time steps in a sequence is flexibly captured by utilizing a dynamic adjustment memory unit, noise interference is better removed, and effective signals of a magnetic target are highlighted, so that the precision of a positioning task is improved.

The invention relates to the technical field of magnetic separation, in particular to a magnetic gradient separation fire metal material evidence screening machine and a multistage magnetic field regulation and control method thereof.The magnetic gradient separation fire metal material evidence screening machine comprises a machine body, a feeding pipe and rotating cylinders are rotationally connected to an inner cavity of the machine body, magnetic separation assemblies are installed between the feeding pipe and the rotating cylinders and between the two rotating cylinders, and driven gears are installed on the outer walls of the feeding pipe and the rotating cylinders; according to the multi-stage magnetic separation device, the multi-stage magnetic separation design is adopted, magnetic force sequentially increased from top to bottom of the magnetic separation assembly is combined with centrifugal force generated by rotation of the feeding pipe and the rotating cylinders, and materials are evenly dispersed and make full contact with the magnetic separation assembly; meanwhile, the valve plate assemblies are sequentially opened in the descending process of the abutting blocks, so that the materials sequentially fall down layer by layer, sorting disorder caused by falling of a large number of materials at a time is avoided, the materials can be kept for enough time on each magnetic separation assembly, it is ensured that metal material evidences with different magnetisms are fully adsorbed, and the screening accuracy is greatly improved.

Provided is a magnetic moment measurement system and method, which belong to the technical field of magnetic moment measurement, and solve the problems of insufficient accuracy, low efficiency, and vulnerability to disturbance from an external magnetic field in the existing magnetic moment measurement technique. The magnetic moment measurement method includes the following steps: acquiring a magnetic field vector and a magnetic gradient tensor at a center of a magnetic sensor array through the magnetic sensor array; calculating an angle of a magnetic moment vector; and according to the angle of the magnetic moment vector, selecting a corresponding magnetic moment inversion formula, and calculating the magnetic moment vector. By constructing the magnetic sensor array, and using the advanced inversion algorithm, this application not only significantly improves the magnetic moment measurement accuracy, but also greatly shortens the measurement cycle, simplifies the measurement system, and reduces the measurement error.

The invention relates to an array magnetic field data error correction method and device based on Transform and computer equipment. The method comprises the following steps: acquiring magnetic field data and an error optimization model; the error optimization model comprises a nonlinear mapping relation between the magnetic field data and a target magnetic gradient tensor, and the error optimization model is obtained by training a target loss function formed by magnetic gradient tensor reconstruction loss, rotation invariance loss and smoothness loss; and inputting the magnetic field data into the error optimization model, and performing dynamic error compensation and data mapping on the magnetic field data according to the attention mechanism and the nonlinear mapping relation of the error optimization model to obtain a target magnetic gradient tensor. By adopting the method, the accuracy of the target magnetic gradient tensor can be improved.

The invention relates to the technical field of magnetic field precision measurement, in particular to an atomic magnetic gradient measurement device and method. Comprising a host which is internally provided with a laser light source and a control circuit thereof, a data acquisition unit and a probe control unit; each probe comprises a polarizer, a collimating and focusing lens, an atomic gas chamber and a photoelectric detector; the laser light source generates frequency-stabilized laser, the laser is divided into a plurality of paths with equal light intensity through the light splitting device, and the plurality of paths of laser enter the plurality of probes through the optical fibers respectively; the magnetometer is provided with a plurality of probes which are completely homologous, laser homology, air chamber excitation homology, clock homology and signal synchronous processing are included, common-mode noise caused by a laser light source, a signal processing circuit and the environment of the magnetometer is reduced in a differential mode, and the magnetic field measurement sensitivity and the system anti-jamming capability are improved; therefore, the influence of geomagnetic diurnal variation and ambient noise on the quality of magnetic field measurement data can be effectively eliminated.

The invention relates to the technical field of geomagnetic vector measurement, and discloses an error correction method of a cross-shaped magnetic gradient tensor measurement system. According to the method, a coupling model containing a sensitivity error, a non-orthogonal error, a zero offset error and an array non-alignment error of a single fluxgate sensor is established, and a fitness function is designed to solve error parameters by utilizing the characteristics of high global search capability and high convergence speed of a firefly optimization algorithm (FA). Compared with the existing particle swarm optimization and the least square method, the method has the advantages that the correction precision of zero offset and non-alignment errors is remarkably improved, the single-sensor zero offset error estimation deviation is smaller than 2%, the array non-alignment angle error deviation is smaller than 1.5%, expensive equipment support is not needed, and real-time on-site implementation can be achieved. The method is suitable for the fields of magnetic anomaly detection, geophysical exploration and the like, and has the advantages of low cost, simplicity and convenience in operation and remarkable correction effect.

The invention relates to the field of magnetic field measurement and sensor error compensation, and provides a magnetic gradient tensor array double-stage calibration method based on direction regularization, which comprises the following steps: acquiring magnetic vector observation data under multiple attitudes; constructing a twelve-parameter error model for explicitly distinguishing an internal error of the sensor from an array attitude error; based on the model, establishing an optimization objective function considering both module value consistency and direction consistency; a two-stage optimization strategy based on a differential evolution algorithm is adopted, in the first stage, all parameters are estimated to achieve coarse calibration, and in the second stage, estimated array attitude error parameters are optimized on the basis of internal error parameters of a fixed sensor; and finally, correcting a magnetic vector observation value according to the estimated calibration parameter, and calculating a magnetic gradient tensor through a symmetric difference method. Under the condition that no external magnetic field reference is needed, the measurement precision is improved by correcting the magnetic vector observation value, the accuracy of magnetic gradient tensor calculation is finally guaranteed, and the method has good engineering adaptability and popularization prospects.

The invention provides a transient electromagnetic near-surface target feature recognition system and method, and relates to the technical field of underground target recognition, and the method comprises the steps: arranging a measurement grid, collecting a response voltage component of each measurement point through a JPMD sensor, calculating a magnetic gradient tensor, generating a target position vector, building a global coordinate system, and carrying out the Gaussian-Newton algorithm, thereby achieving the feature recognition of a transient electromagnetic near-surface target. And determining a positioning result based on the actual detection value and the predicted value of the single dipole model. The length-width ratio of the target is obtained by decomposing the magnetic gradient tensor, the attenuation time coefficient is corrected in combination with the soil conductivity to judge the conductivity of the target, clustering analysis is carried out on the target to improve the classification accuracy, and finally, target recognition models are trained for different clusters to recognize the types of the targets in the clusters. And the real-time target is identified through the corresponding target identification model after being distributed to the cluster. According to the method, multi-measurement-point data are fused, and the positioning precision and the target recognition efficiency are improved.

The invention discloses a magnetic target boundary recognition method and system based on a magnetic gradient tensor, and relates to the technical field of geophysical exploration and industrial nondestructive testing, and the method comprises the following steps: collecting spatial magnetic gradient tensor data through a magnetic gradient sensor array, and obtaining nine components of the magnetic gradient tensor; calculating the vertical guide modulus of the vertical component of the magnetic gradient tensor; calculating a Z-direction analysis signal ASAz and a vertical guide thereof; a boundary recognition amount is generated by a ratio operation, and a boundary position of the magnetic target is determined based on a maximum value position of the boundary recognition amount. According to the method, a vertical component derivative and analytic signal derivative dual-derivative coupling mechanism is combined for the first time, the limitation that a traditional method depends on a single parameter is overcome, the vertical component derivative accurately captures the change rate of the boundary in the vertical direction, and the analytic signal derivative effectively suppresses background noise.

The invention belongs to the technical field of magnetic field measurement and instruments, and relates to a magnetic gradient tensor field interpolation method under physical potential field constraint, which comprises the steps of establishing a Gaussian process model of a magnetic gradient tensor field, acquiring a magnetic potential core and performing hyper-parameter optimization. According to the method, multi-component interpolation and curving are fused into a unified Gaussian process regression framework, and the multi-component interpolation and the curving are subjected to potential field physical constraints in a unified manner; a complete potential field physical constraint is used, meanwhile, no-rotation and no-divergence constraints are met, and magnetic gradient tensor measurement data interpolation with measurement errors is more accurate and better in anti-interference capability; by introducing a complete physical constraint fusion Gaussian process regression framework, the magnetic gradient tensor interpolation precision and stability are improved. Based on the magnetic potential core, all magnetic gradient tensor components can be modeled at the same time in the joint probability model, physical constraints among the components are guaranteed, non-planar data which are distributed at will can be processed naturally based on a Gaussian process regression framework, and an additional potential field continuation step is not needed.

The invention discloses a slope monitoring method and system based on an unmanned aerial vehicle, and relates to the technical field of intelligent geological disaster monitoring, and the method comprises the steps: carrying a magnetic gradient measurement unit and a laser radar through the unmanned aerial vehicle, and collecting magnetic gradient tensor collection and slope surface point cloud from multiple heights and multiple routes; on the basis of a gradient adaptive weighted total variation inversion method, slope gradient information extracted by a digital elevation model is introduced into regularization weight adjustment, so that an inversion result can be adaptively adjusted in different gradient areas; based on a magnetic susceptibility distribution model, a magnetic construction adaptive clustering and risk index calculation method is used, and through amplitude density index and gradient constraint search, clustering identification and risk quantitative partitioning of a high-gradient accumulation area are carried out. Therefore, expansion from surface slope deformation monitoring to deep concealed structure detection is realized, and concealed slip zones or fissure zones can be accurately revealed under complex terrain conditions.

The invention discloses an unmanned ship gravity and magnetic measurement method and system, and belongs to the technical field of geophysical exploration, and the method comprises the steps: obtaining the real-time attitude data of an unmanned ship, and generating an inclination angle compensation parameter; adjusting data acquisition frequency according to the inclination angle compensation parameter, and generating a positioning enhancement signal; triggering collection operation data based on the positioning enhancement signal, and generating gravity original data and magnetic force original data; extracting magnetic field gradient abrupt change points in the magnetic force original data, and generating wave characteristic parameters; fusing the inclination angle compensation parameter, the wave characteristic parameter and the gravity original data to generate a wave noise compensation value; and correcting the wave noise compensation value to generate target gravity field data. According to the method, three core technology systems of dynamic inclination angle closed-loop compensation, magnetic gradient-wave feature mapping modeling and time accurate alignment triggering are adopted, the interference influence of wave noise on a gravity field can be effectively overcome, and time-space synchronization jump of gravity and magnetic measurement is achieved.

The invention belongs to the technical field of magnetic field detection, and discloses a cross-shaped variable baseline magnetic flux gate array and method for measuring a three-order magnetic gradient tensor. The cross-shaped variable baseline magnetic flux gate array comprises a cross-shaped array rack, each supporting arm is provided with a sliding groove with the length of 1, and a sensor is installed on each sliding groove in a clamped mode. A sensor is mounted at the central point of the cross array rack; the baseline distances d between the adjacent sensors are equal, and the sensors slide in the corresponding sliding grooves. According to the adjusting method, the baseline distance is adjusted through the sliding groove. According to the rotation correction method, the surrounding sensors are corrected through the middle sensor, the measurement precision is improved, the zero-order magnetic gradient tensor and the first-order magnetic gradient tensor at the position of each sensor and the second-order magnetic gradient tensor and the third-order magnetic gradient tensor at the position of the center sensor can be measured at the same time, rich target magnetic field information is obtained, and the measurement accuracy is improved. The engineering practical value is realized.

The invention discloses a ship far-field magnetic field inversion method based on magnetic gradient tensor. According to a traditional naval vessel magnetic field inversion method based on magnetic induction intensity, in the naval vessel magnetic field separation step, an additional sensor needs to be arranged for obtaining a reference background geomagnetic field, measurement errors are difficult to control, measurement data are inaccurate, and errors are generated during naval vessel far-field magnetic field inversion. According to the method, the magnetic gradient tensor is used as data for constructing the magnetic field model, a background geomagnetic field does not need to be measured, the measurement steps are simplified, and meanwhile inversion of the far-field magnetic field of the naval vessel has high accuracy. According to the method, the ship model is solved by using the MOAEMDE algorithm, control parameters of the algorithm can be adaptively adjusted, repeated manual parameter configuration according to different measurement environments is not needed, and the method is high in adaptability and convenient to use.

The invention discloses a ferromagnetic material defect identification method and system based on magnetic gradient tensor measurement, and relates to the technical field of nondestructive testing, and the method comprises the following steps: acquiring magnetic gradient tensor data of a to-be-tested piece; calculating a total horizontal derivative based on the magnetic gradient tensor data; calculating a z-direction partial derivative of each component based on the total horizontal derivative and calculating a vertical derivative based on the magnetic gradient tensor data; and identifying a defect boundary by using the magnetic gradient tensor fusion derivative detector and the magnetic gradient tensor anti-noise boundary detector, and outputting a defect profile diagram. According to the invention, the MGTFDED and MGTNRED detectors specially designed for industrial defect detection scenes are provided for the first time, and the problem that a geophysical method is not suitable for direct transplantation is solved. According to the method, the edges of various defects from surface cracks to deep buried holes and the like can be identified with high precision, and the accuracy, noise resistance and intelligent level of detection are remarkably improved.

The invention relates to a single-vector magnetometer motion direction magnetic gradient anomaly detection method, which comprises the following steps: based on a single-sensor magnetic gradient measurement technology, obtaining an x-axis motion direction magnetic gradient signal through spatial sampling; preprocessing the magnetic gradient signal in the x-axis motion direction; presetting an orthogonal basis function of the magnetic gradient in the x-axis motion direction; and carrying out magnetic gradient anomaly detection on the preprocessed signal based on a preset orthogonal basis function. The method is superior to a traditional vertical motion directional array double-sensor column magnetic gradient anomaly OBF detection method under the conditions of low noise ratio and platform shaking, has the advantages of being high in real-time performance, low in cost, small in size and the like, and shows a good application prospect under the scenes of danger detection, explosion removal, intrusion monitoring and the like.

The invention provides a movement control device, and the device comprises a plurality of magnet groups which are fixed at a first side edge of a movable workbench and are arranged in a non-collinear manner, and each magnet group comprises a pair of magnets with opposite polarities, so as to form a gradient magnetic field region; the Hall sensors are fixed to the second side edge of the main substrate, the second side edge of the main substrate is opposite to the first side edge of the movable workbench, and the induction face of each Hall sensor is parallel to the magnetic gradient face of the corresponding magnet set in the magnet sets; and the controller is used for receiving sensing data of the plurality of Hall sensors to form a real-time data matrix and controlling the movable workbench to move to a zero position according to the real-time data matrix. Through the technical scheme, the movable workbench can accurately move to the zero position, the manufacturing cost is reduced, and meanwhile the structure is simplified.

The present invention belongs to the technical field of underwater weak magnetic target detection, and proposes an underwater weak magnetic moving target detection method and system based on unmanned dual aircraft. First, two unmanned aircraft equipped with geomagnetic gradient tensor instruments are used to cooperatively locate underwater magnetic targets, initially eliminating the interference of the geomagnetic field on measurement; then, the rough positioning coordinates are projected onto three planes, and binary Hough detection including point accumulation and power accumulation is performed on the tracks of the three planes respectively, so as to maximize the extraction of the true track of the weak magnetic target from the positioning data; finally, when the Hough line detection is unsuccessful, the amount of data to be detected is reduced, so that the possible tracks can be approximately linearized in a short time. The detection of underwater weak magnetic moving targets is ultimately realized through the above method.

The application discloses a kind of ocean stereo magnetic survey system and method based on unmanned platform, belong to marine detection equipment technical field, including water surface magnetic transverse gradient measurement subsystem, underwater magnetic total field measurement subsystem, ground magnetic diurnal variation observation station and data synchronization and compensation processing center.Processing center, built-in improved 18 items Tolles-Lawson magnetic interference compensation model, real-time solution and eliminate platform constant field, induction field and eddy current field interference.The application is realized through the cooperation of combined navigation and automatic roll reduction device, attitude depth adjustment mechanism, water surface / underwater platform high-precision attitude positioning and attitude keeping;After diurnal variation correction, attitude correction and position calculation, water surface transverse magnetic gradient and vertical magnetic gradient are solved, and water surface-underwater stereo magnetic survey cooperative operation and high dynamic platform magnetic interference real-time compensation are realized, which significantly improves the precision, efficiency and spatial resolution of marine magnetic anomaly detection.

According to the guidance device and method based on magnetic detection, magnetic field information on the two sides of a projectile body is synchronously collected and magnetic field gradients on the two sides of the projectile body are obtained by utilizing the rule that a target magnetic gradient is larger than a surrounding environment magnetic gradient, and then the magnetic field gradient difference between the two sides of the projectile body is obtained, so that guidance information is generated, and the motion direction of the projectile body is controlled. For an ultra-high-speed torpedo or other missiles under limited conditions, the traditional guidance technology is limited, the device and the method solve the problem by introducing magnetic guidance, and the hit probability and the striking effect of weapons such as the torpedo and the missiles are improved.

The invention belongs to the technical field of degaussing, and relates to a ship winding degaussing current solving method based on a gradient tensor, which comprises the following steps: acquiring the magnetic gradient tensor of a plane ship when coils are not electrified; respectively performing simulation electrification on the winding coils to obtain the magnetic gradient tensor of the electrified measurement plane; and calculating an efficiency matrix of the magnetic gradient tensor excited by the unit current. The gradient of the geomagnetic field is extremely small, direct detection of the magnetic gradient tensor of the ship and the electrified coil can better reflect the magnetic characteristics of the ship and the coil compared with detection of a magnetic vector, and better resolution is achieved for magnetic field changes caused by magnetic anomalies; under the motion platform, the magnetic gradient tensor is insensitive to the attitude angle error, and more accurate detection data can be obtained; in addition, the gradient tensor is weak in response to time-varying geomagnetic disturbance, and has higher anti-interference capability. Therefore, according to the method, the accuracy of ship magnetic field modeling and degaussing current calculation is improved, and the magnetic stealth performance of a ship facing high-sensitivity magnetic gradient detection equipment is enhanced.

The invention provides a single-axis magnetic gradient detection method and system based on an active attitude, and relates to the field of single-axis magnetic gradient detection.The method comprises the steps that the attitude of a carrier is adjusted according to the magnetic gradient detection requirement; acquiring magnetic gradient information, position information of a carrier and attitude information of the carrier; constructing an inversion equation of active attitude single-axis magnetic gradient detection data; and obtaining three-dimensional magnetic distribution of the detection space by combining the magnetic gradient information, the position information and the attitude information with an inversion equation. According to the technical scheme, a solution can be provided for single-axis magnetic gradient detection of the dynamic load platform, and the detection efficiency and the detection precision are effectively improved by actively utilizing the attitude change information.

The utility model relates to an unmanned aerial vehicle for underground electromagnetic anomaly detection, and belongs to the technical field of unmanned aerial vehicle detection. Comprising an unmanned aerial vehicle body; the magnetic gradient detection device is carried on the unmanned aerial vehicle body; the magnetic gradient detection device comprises a telescopic supporting arm, a posture switching mechanism and at least two magnetic sensing units. The at least two magnetic sensing units are arranged at intervals in the axial direction of the telescopic supporting arm; the posture switching mechanism is connected with the unmanned aerial vehicle body and the telescopic supporting arm and used for driving the telescopic supporting arm to be switched between the horizontal storage position and the vertical working position. The vertical distance between the at least two magnetic sensing units is obviously increased in the vertical direction, and the requirement of geomagnetic vertical gradient measurement for the length of a sensor base line is met.

The invention relates to a geologic body burial depth detection method and system based on a gravity and magnetic Tilt gradient, and belongs to the technical field of geological prospecting. The burial depth detection method comprises the following steps: receiving gravity or magnetic field anomaly observation data of a target area; performing gridding processing on the gravity or magnetic field anomaly observation data to obtain gridding data; calculating a Tilt gradient value of each grid point in the grid based on the gridding data to obtain a Tilt gradient value data set; traversing the Tilt gradient value data set, screening a grid point of which the Tilt gradient value meets a preset gradient value requirement as a target point, and obtaining a plane coordinate of the target point in a grid; determining an abnormal center point of the target area according to the gridding data, and determining the position of a corresponding target geologic body; acquiring a plane coordinate of the abnormal center point in the grid, and calculating a corresponding distance value in combination with the plane coordinate of the target point; and obtaining the burial depth value of the target geologic body according to the distance value. According to the invention, the burial depth detection precision of the weak abnormal geologic body can be improved.

The invention discloses an unmanned aerial vehicle magnetic gradient data soft compensation method and system based on semi-supervised learning, and relates to the technical field of aviation geophysical exploration, and the method comprises the steps: designing an octagonal calibration flight scheme, enabling an unmanned aerial vehicle to execute a single maneuvering action in each route, and obtaining the response data of an interference magnetic field to the flight attitude change; actually measuring the high-altitude compensation flight data and the low-altitude survey line flight data based on the high-altitude compensation flight data and the low-altitude survey line flight data in the response data of the interference magnetic field to the flight attitude change, establishing a simulation dynamic measurement noise data set through a forward modeling formula, and dividing the simulation dynamic measurement noise data set into a training set, a verification set and a test set; through an improved octagonal calibration flight scheme and in combination with a Transform-based semi-supervised learning residual error compensation method, the soft compensation precision and efficiency are improved.

The invention discloses a geomagnetic gradient tensor depth representation learning method and system, and belongs to the technical field of information processing, and the method comprises the steps: obtaining a geomagnetic three-component data matrix of a magnetic object, and building an original gradient tensor data set; generating a gradient matrix based on the original gradient tensor data set, and performing orthogonal decomposition on the gradient matrix to obtain mutually independent rotation isovariant features and direction sensitive features; inputting the rotation isovariant features and the direction sensitive features into a rotation isovariant convolutional neural network for feature extraction; constructing a geometric constraint loss function including an angle constraint loss function and a direction constraint loss function, and optimizing the training network; the geomagnetic gradient tensor data is subjected to deep representation based on the trained network, the innovative gradient matrix orthogonal decomposition technology solves the problem that rotation invariance and direction sensitivity are difficult to consider at the same time, the feature representation accuracy is improved by about 30-40%, the processing speed is improved by 2-3 times, and the anti-interference capability is remarkably enhanced.

The invention provides a black box magnetic induction searching device and method.The black box magnetic induction searching device comprises an MCU main control circuit, a data acquisition front-end processing circuit and a magnetic gradient sensor, the magnetic gradient sensor comprises two magnetic probes used for detecting the magnetic field intensity of different positions, and the two magnetic probes form a magnetic gradient difference; the magnetic gradient sensor is connected with the input end of the data acquisition front-end processing circuit, the output end of the data acquisition front-end processing circuit is connected with the MCU main control circuit, and the data acquisition front-end processing circuit is used for converting an acquired analog magnetic signal into a digital signal and then sending the digital signal to the MCU main control circuit for analysis and processing. And the MCU main control circuit matches the acquired magnetic field intensity data with a preset magnetic field intensity threshold value, and determines the position of the black box according to a matching result. According to the invention, accurate positioning and searching of the black box at the depth of 0.5 m from the ground are realized, the problem that the black box cannot be searched and positioned when an airplane crashes on the land is solved, and rapid and effective searching of the black box on the land is realized.

The invention discloses an electromagnetic anomaly detection method based on tensor shrinkage and orthogonal basis function decomposition, and belongs to the technical field of magnetic detection and correction, and the method comprises the steps: enabling a metal target to be equivalent to a magnetic dipole, and building an AC radiation field model; then, deducing a magnetic gradient tensor of a metal target scattered field; next, taking the square of the reduced tensor of the scattering field as a detection quantity, and calculating a primary function of mutual orthogonality of the detection quantity; and finally, establishing an energy function to complete electromagnetic anomaly detection of the metal target. According to the invention, the non-ferromagnetic metal target in the space can be effectively detected based on the electromagnetic emission source, the signal-to-noise ratio of electromagnetic anomaly detection is improved, and the method is of great significance to detection of metal anomalous objects in anti-submarine, anti-mine, anti-landmine and other scenes.