Magnetic susceptibility sounding method, device, equipment, medium and product

Abstract

According to the magnetic susceptibility sounding method, device and equipment, the medium and the product provided by the invention, the relative difference value of cross-power spectrum in-phase parts of each observation station and base station with the same frequency is analyzed through the method, and then the relative magnetic difference of different depths can be obtained according to the fact that different frequencies correspond to different skin depths; therefore, relative magnetic anomalies of different measuring points can be evaluated more accurately and efficiently under the condition that the signal-to-noise ratio is low, so that magnetic field sounding is realized, the defect of sounding by a traditional magnetic method is overcome, the detection accuracy of a magnetic geologic body is improved, and magnetic difference distribution of different depths underground can be evaluated conveniently, quickly, simply and efficiently.

Description

Technical Field

[0001] The present application relates to the technical field of geophysical exploration, and particularly to a magnetic susceptibility sounding method, device, equipment, medium and product. Background Art

[0002] The "Magnetic Susceptibility Sounding Method" with Chinese Patent No. 202111459237.2 proposes to achieve quasi-static magnetic susceptibility sounding by observing the magnetic field signal of plane electromagnetic waves, that is, to evaluate the magnetic susceptibility differences at different underground depths through the relative differences of magnetic fields with different frequencies observed at the measurement station and the base station. Specifically, it is evaluated by calculating the relative differences between the magnetic field spectra of the measurement station and the base station. This algorithm can achieve good results when the signal-to-noise ratio of the magnetization field is relatively high. However, when the magnetic field source signal of the natural source magnetotelluric is weak, the magnetization anomaly field will be very weak and is extremely easy to be masked by noise. Therefore, it is very difficult to extract an effective magnetization field. Summary of the Invention

[0003] The present application provides a magnetic susceptibility sounding method, device, equipment, medium and product, which can solve one of the problems existing in the background art.

[0004] To achieve the above object, the present application adopts the following technical solutions:

[0005] In a first aspect, a magnetic susceptibility sounding method is provided, and the method includes:

[0006] Observing mutually orthogonal horizontal magnetic fields at a measurement station, a first base station and a second base station respectively to obtain a time-aligned magnetic field time series of the measurement station, a magnetic field time series of the first base station and a magnetic field time series of the second base station;

[0007] Performing power spectrum statistical estimation on the magnetic field time series of the measurement station, the magnetic field time series of the first base station and the magnetic field time series of the second base station to obtain a first magnetic field cross-power spectrum between the first base station and the second base station, a second magnetic field cross-power spectrum between the measurement station and the first base station, and a third magnetic field cross-power spectrum between the measurement station and the second base station, and the first magnetic field cross-power spectrum, the second magnetic field cross-power spectrum and the third magnetic field cross-power spectrum are represented by frequency;

[0008] Calculating relative magnetization differences between the measurement station and the first base station and the second base station according to the first magnetic field cross-power spectrum, the second magnetic field cross-power spectrum and the third magnetic field cross-power spectrum; and

[0009] Obtaining magnetic difference data at different skin depths by combining the relative magnetization differences according to different skin depths corresponding to different frequencies, and completing magnetic susceptibility sounding.

[0010] Based on the above technical solution, by analyzing the relative difference of the in-phase part of the cross-power spectra of each measuring station and the base station at the same frequency through the above method, and then according to different frequencies corresponding to different skin depths, the relative magnetic differences at different depths can be obtained. Thus, in the case of low signal-to-noise ratio, the relative magnetic anomalies of different measuring points can be evaluated more accurately and efficiently, so as to realize magnetic sounding. In this way, the deficiencies of traditional magnetic sounding are made up, the detection accuracy of magnetic geological bodies is improved, and the magnetic difference distribution at different underground depths can be evaluated conveniently, quickly, simply and efficiently.

[0011] In a possible design of the first aspect, according to the first magnetic cross-power spectrum, the second magnetic cross-power spectrum and the third magnetic cross-power spectrum, the relative magnetization difference between the measuring station and the first base station and the second base station is calculated as follows:

[0012] Calculate the relative magnetization difference ε x (f) in the x direction of the horizontal magnetic field and the relative magnetization difference ε y (f) in the y direction according to the following formula:

[0013]

[0014] where a represents the measuring station, b represents the first base station, c represents the second base station, f is the frequency, P xab (f) is the cross-power spectrum in the x direction of the second magnetic field, P xac (f) is the cross-power spectrum in the x direction of the third magnetic field, P xbc (f) is the cross-power spectrum in the x direction of the first magnetic field, P yab (f) is the cross-power spectrum in the y direction of the second magnetic field, P yac (f) is the cross-power spectrum in the y direction of the third magnetic field, P ybc (f) is the cross-power spectrum in the y direction of the first magnetic field, and Re[] represents taking the real part of a complex number.

[0015] In a possible design of the first aspect, the cross-power spectrum in the x direction of the first magnetic field, the cross-power spectrum in the y direction of the first magnetic field, the cross-power spectrum in the x direction of the second magnetic field, the cross-power spectrum in the y direction of the second magnetic field, the cross-power spectrum in the x direction of the third magnetic field, and the cross-power spectrum in the y direction of the third magnetic field are obtained through the following calculation formulas:

[0016] P xab (f) = F{H xa (t)} · F{H xb (t)} * P yab (f) = F{H ya (t)} · F{H yb (t)} *

[0017] P xac (f) = F{Hxa (t)}·F{H xc (t)} * , P yac (f)=F{H ya (t)}·F{H yc (t)} *

[0018] P xbc (f)=F{H xb (t)}·F{H xc (t)} * , P ybc (f)=F{H yb (t)}·F{H yc (t)} *

[0019] Among them, F represents the Fourier transform, * represents the complex conjugate, t represents time, H xa (t), H ya (t) respectively represent the x-direction time series of the magnetic field at the measurement station and the y-direction time series of the magnetic field at the measurement station, H xb (t), H yb (t) respectively represent the x-direction time series of the magnetic field at the first base station and the y-direction time series of the magnetic field at the first base station, H xc (t), H yc (t) respectively represent the x-direction time series of the magnetic field at the second base station and the y-direction time series of the magnetic field at the second base station. The cross-power spectrum result is a complex number, including amplitude and phase information.

[0020] In a possible design of the first aspect, the first base station and the second base station are selected in a place without electromagnetic interference and with relatively weak rock and ore magnetism relative to the target body, and the distance between the first base station and the second base station, the distance between the first base station and the measurement station, and the distance between the second base station and the measurement station are greater than 3 times the influence radius of the noise source. The measurement station, the first base station, and the second base station are simultaneously within the coverage range of the same regional field source, ensuring that the signals among the three stations of the measurement station, the first base station, and the second base station are correlated while the noise is uncorrelated.

[0021] In a possible design of the first aspect, the formula for the skin depth is:

[0022]

[0023] Among them, ρ is the resistivity.

[0024] For the method according to claim 5, wherein the resistivity ρ is obtained according to the magnetic field far-reference magnetotelluric algorithm.

[0025] In a second aspect, a magnetic susceptibility sounding device is provided, the device comprising:

[0026] An acquisition unit configured to respectively observe mutually orthogonal horizontal magnetic fields at a measurement station, a first base station, and a second base station, to obtain a time-aligned magnetic field time series of the measurement station, a magnetic field time series of the first base station, and a magnetic field time series of the second base station;

[0027] An estimation unit configured to perform power spectrum statistical estimation on the magnetic field time series of the measurement station, the magnetic field time series of the first base station, and the magnetic field time series of the second base station, to obtain a first magnetic field cross-power spectrum between the first base station and the second base station, a second magnetic field cross-power spectrum between the measurement station and the first base station, and a third magnetic field cross-power spectrum between the measurement station and the second base station, wherein the first magnetic field cross-power spectrum, the second magnetic field cross-power spectrum, and the third magnetic field cross-power spectrum are represented by frequency;

[0028] A calculation unit configured to calculate, according to the first magnetic field cross-power spectrum, the second magnetic field cross-power spectrum, and the third magnetic field cross-power spectrum, a relative magnetization difference between the measurement station and the first base station and the second base station; and

[0029] A sounding unit configured to, according to different skin depths corresponding to different frequencies, in combination with the relative magnetization difference, obtain magnetic difference data at different skin depths, thereby completing magnetic susceptibility sounding.

[0030] In a third aspect, an electronic device is provided, the electronic device comprising: a processor, and a memory coupled to the processor, the memory being configured to store a computer program; the processor being configured to execute the computer program stored in the memory, so that the electronic device executes the method according to any one of the possible implementation manners in the first aspect.

[0031] In a fourth aspect, a computer-readable storage medium is provided, comprising a computer program or instruction, which, when running on a computer, causes the computer to execute the method according to any one of the possible implementation manners in the first aspect.

[0032] In a fifth aspect, a computer program product is provided, comprising: a computer program or instruction, which, when running on a computer, causes the computer to execute the method according to any one of the possible implementation manners in the first aspect. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for use in the embodiments or the description of related technologies. Obviously, the accompanying drawings in the following description are only some embodiments of the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0034] Figure 1 is a flowchart of a method for estimating the quasi-static magnetic susceptibility of plane electromagnetic waves provided by an embodiment of the present application;

[0035] Figure 2 is a magnetic field auto-power spectrum diagram provided by an embodiment of the present application;

[0036] Figure 3 is a real part diagram of the magnetic field cross-power spectrum provided by an embodiment of the present application;

[0037] Figure 4 is a diagram of the quasi-static magnetic susceptibility calculated by different algorithms provided by an embodiment of the present application. Among them, label 1: calculation result of the real part of the cross-power spectrum; label 2: calculation result of the spectrum difference between the measurement station and base station 1; label 3: calculation result of the spectrum difference between the measurement station and base station 2;

[0038] Figure 5 is a diagram of the quasi-static magnetic susceptibility at different depths provided by an embodiment of the present application. Detailed implementation manners

[0039] In order to make the objectives, technical solutions, and advantages of the present application more clear and understandable, the following further details the present application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] It should be noted that although the functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order from the module division in the device or the order in the flowchart. Terms such as "first" and "second" in the description, claims, and the above accompanying drawings are used to distinguish similar objects and do not necessarily describe a specific order or sequence.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0042] Before introducing the embodiments of the present application, the method principle on which the embodiments of the present application are based will be described first.

[0043] Under the action of an alternating magnetic field, a conductive and magnetic body within the skin depth range of the alternating magnetic field will be excited by the alternating magnetic field to generate a magnetized secondary magnetic field and an induced secondary magnetic field. In the quasi-static frequency band, when the depth of the target body is much smaller than the skin depth, it is in a low induction number state. Under this condition, the induced secondary magnetic field is much smaller than the primary magnetic field and lags behind the primary magnetic field. If the primary field is taken as a reference, there is a phase difference between the induced field and the primary magnetic field, which can be decomposed into an in-phase component (real part) and a quadrature component (imaginary part). The in-phase component is smaller than the quadrature component, while the magnetization field is in phase with the primary field and has only an in-phase component. For strongly magnetic ore bodies, the in-phase component of the induced field is much smaller than the in-phase component of the magnetization field.

[0044] Under the theory of quasi-static plane wave electromagnetic sounding, when the distance between the measuring station and the base station is less than the wavelength of the field source in air (wavelength = wave velocity / frequency, when the frequency is 10 kHz, the corresponding wavelength in air is about 30 km, and the lower the frequency, the longer the wavelength), it can be considered that the primary fields of the measuring station and the base station are of the same origin. If the first and second base stations are selected in an area with locally uniform non-conductive and non-magnetic surrounding rocks, that is, the induced magnetic field and the magnetization magnetic field on the base stations can be ignored.

[0045] Let the complex exponential expression of the primary magnetic field be H1 = A1e jωt , where the amplitude is A1, e is the natural constant, j is the imaginary unit, t is the time, the angular frequency ω = 2πf, and the frequency is f.

[0046] Then the total observed fields H a , H b , H c are respectively:

[0047] Measuring station: H a = H1 + H m + H g + H na ;

[0048] First base station: H b = H1 + H nb ;

[0049] Second base station: H c = H1 + H nc .

[0050] Among them, H m is the magnetization magnetic field of the measuring station: H m = A m e jωt = εA1e jωt , A m is the amplitude of the magnetization magnetic field, and ε = A m / A1 is the magnetization coefficient;

[0051] H gThe induced magnetic field of the measuring station: A g is the amplitude of the induced magnetic field, and is the phase difference between the induced field and the primary field;

[0052] H na , H nb , H nc are the observation noises of the three stations respectively.

[0053] Since the primary field and the secondary field are correlated, while the noise is uncorrelated with the primary field and the secondary field, and the noises among the three stations are uncorrelated with each other, that is:

[0054]

[0055] The cross-power spectrum between the measuring station and the first base station:

[0056]

[0057] So

[0058]

[0059] The cross-power spectrum between the measuring station and the second base station:

[0060]

[0061] So

[0062]

[0063] The cross-power spectrum between the first base station and the second base station:

[0064]

[0065] So:

[0066]

[0067] is the in-phase component of the induced secondary magnetic field. Under the condition of low induction number, its value is very small. For strongly magnetic ore bodies, it can be considered that Therefore, when studying strongly magnetic ore bodies, the calculation result is approximately equal to the ratio of the magnetization field to the primary field, that is, approximately equal to the magnetization coefficient,

[0068]

[0069] If only one base station is set, it is required that the noise at the base station location is very small, and the calculation is carried out according to the following algorithm

[0070]

[0071] The previous algorithm is calculated according to the spectrum as follows:

[0072]

[0073] Assume that the noise at the measurement station and the base station is both 0, and when studying strongly magnetic ore bodies, there is:

[0074]

[0075] It can be seen that only when the noise at the measurement station and the base station is 0, the calculation result is approximately equal to the ratio of the magnetization field to the primary field, that is, approximately equal to the magnetic susceptibility. However, if the noise is strong, the calculation result will bring a large error.

[0076] Based on the above analysis, as Figure 1 shown, the embodiment of the present application provides a method for estimating the quasi-static magnetic susceptibility of plane electromagnetic waves, which involves the following processes:

[0077] S1. Synchronously observe the mutually orthogonal horizontal alternating magnetic fields at the measurement station and two base stations to obtain the magnetic field time series H xa (t), H ya (t) and the electric field time series E xa (t), E ya (t) of the measurement station, and the magnetic field time series H xb (t), H yb (t) of the first base station, and the magnetic field time series H xc (t), H yc (t) of the second base station, where x and y represent the mutually orthogonal horizontal directions, a represents the measurement station, b represents the first base station, c represents the second base station, H xa (t), H ya (t) respectively represent the magnetic field time series in the x direction and the magnetic field time series in the y direction of the measurement station, H xb (t), H yb (t) respectively represent the magnetic field time series in the x direction and the magnetic field time series in the y direction of the first base station, H xc (t), H yc (t) respectively represent the magnetic field time series in the x direction and the magnetic field time series in the y direction of the second base station;

[0078] S2. Perform power spectrum statistical estimation on the magnetic field time series of each measurement station and base station observed in the same time period in step S1 to obtain the cross-power spectrum of the magnetic fields of the first base station and the second base station, the cross-power spectrum of the magnetic fields of the measurement station and the first base station, and the cross-power spectrum of the magnetic fields of the measurement station and the second base station:

[0079] P xab (f) = F{H xa (t)} · F{H xb (t)} * ,P yab(f) = F{H ya (t)}·F{H yb (t)} *

[0080] P xac (f) = F{H xa (t)}·F{H xc (t)} * , P yac (f) = F{H ya (t)}·F{H yc (t)} *

[0081] P xbc (f) = F{H xb (t)}·F{H xc (t)} * , P ybc (f) = F{H yb (t)}·F{H yc (t)} *

[0082] Where: F represents the Fourier transform, * represents the complex conjugate, the cross-power spectrum result is a complex number, containing amplitude and phase information, f is the frequency, P xab (f) is the cross-power spectrum of the second magnetic field in the x direction, P xac (f) is the cross-power spectrum of the third magnetic field in the x direction, P xbc (f) is the cross-power spectrum of the first magnetic field in the x direction, P yab (f) is the cross-power spectrum of the second magnetic field in the y direction, P yac (f) is the cross-power spectrum of the third magnetic field in the y direction, P ybc (f) is the cross-power spectrum of the first magnetic field in the y direction.

[0083] S3. Calculate the magnetization coefficient based on the cross-power spectrum data obtained in step S2, defined as the quasi-static magnetic susceptibility, and calculate it separately for different directions, representing the quasi-static magnetic susceptibilities in different directions:

[0084]

[0085] Where: Re[] represents taking the real part of a complex number.

[0086] S4. According to different frequencies corresponding to different skin depths, combined with the quasi-static magnetic susceptibilities obtained in step S3, obtain the magnetic difference data at different depths. The skin depth calculation formula is:

[0087]

[0088] In the formula: f is the frequency; ρ is the resistivity, which is obtained according to the far - reference magnetotelluric algorithm of the magnetic field. The following algorithm can be selected. Of course, there can also be other algorithms:

[0089] If the magnetic field of the first base station is used as the reference, then

[0090]

[0091] If the magnetic field of the second base station is used as the reference, then

[0092]

[0093] In the formula: μ is the magnetic permeability; ω is the angular frequency.

[0094] Furthermore, the first base station and the second base station are selected in an area with locally uniform non - conducting and non - magnetic surrounding rocks, within the coverage range of the same regional field source. And the distance between the base stations and between the base station and the measuring station must be greater than 3 times the influence radius of the noise source (this radius is generally the skin depth corresponding to the noise source frequency), ensuring that the primary fields among the three stations are correlated while the noises are uncorrelated.

[0095] A plane - wave quasi - static susceptibility sounding method according to an embodiment of the present application has the following advantages: By analyzing the relative difference of the in - phase part of the cross - power spectra of each measuring station and the base station at the same frequency through the above method, and then according to different skin depths corresponding to different frequencies, the relative magnetic differences at different depths can be obtained. Thus, the relative magnetic anomalies of different measuring points can be evaluated more accurately and efficiently, thereby realizing magnetic sounding, making up for the deficiencies of traditional magnetic sounding, improving the detection accuracy of magnetic geological bodies. Therefore, with this method, the magnetic difference distribution at different underground depths can be evaluated conveniently, quickly, simply and efficiently.

[0096] Specific application example:

[0097] Such as Figure 2 shows the auto - power spectrum in the x - direction of a certain measuring station and two base stations; such as Figure 3 shows the real part of the cross - power spectra between every two of the three stations; it can be seen that the auto - power spectra and the real parts of the cross - power spectra are consistent macroscopically and have differences locally, which are considered to be mainly caused by the observed noise; Figure 4 are the magnetic susceptibility coefficients calculated according to the spectral differences between the measuring station and a single base station, and the magnetic susceptibility coefficients calculated according to the real parts of the cross - power spectra between every two of the three stations. It can be seen that the calculation results of the spectral differences according to a single base station are different due to different base stations. Especially when the spectral amplitude is low, the perturbation is large, while the calculation results according to the real parts of the cross - power spectra are more stable. Figure 5 are the quasi - static susceptibilities at different depths, and the depth is obtained according to the apparent resistivity and the skin depth. The figure shows that a relatively strong magnetic ore body appears at about 1600 m depth.

[0098] The embodiment of the present application also provides a magnetic susceptibility sounding device, which includes:

[0099] An acquisition unit, configured to respectively observe mutually orthogonal horizontal magnetic fields at a measuring station, a first base station, and a second base station, so as to obtain a time-aligned measuring station magnetic field time series, a first base station magnetic field time series, and a second base station magnetic field time series;

[0100] An estimation unit, configured to perform power spectrum statistical estimation on the measuring station magnetic field time series, the first base station magnetic field time series, and the second base station magnetic field time series, so as to obtain a first magnetic field cross-power spectrum between the first base station and the second base station, a second magnetic field cross-power spectrum between the measuring station and the first base station, and a third magnetic field cross-power spectrum between the measuring station and the second base station, where the first magnetic field cross-power spectrum, the second magnetic field cross-power spectrum, and the third magnetic field cross-power spectrum are represented by frequencies;

[0101] A calculation unit, configured to calculate a relative magnetization difference between the measuring station and the first base station and the second base station according to the first magnetic field cross-power spectrum, the second magnetic field cross-power spectrum, and the third magnetic field cross-power spectrum; and

[0102] A sounding unit, configured to obtain magnetic difference data at different skin depths according to different skin depths corresponding to different frequencies and in combination with the relative magnetization difference, so as to complete magnetic susceptibility sounding.

[0103] The embodiment of the present application also provides an electronic device, including: a processor and a memory coupled to the processor, where the memory is configured to store a computer program; the processor is configured to execute the computer program stored in the memory, so that the electronic device executes the method described in any one of the above embodiments.

[0104] The electronic device may be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The electronic device may include, but is not limited to, a processor and a memory.

[0105] The so-called processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor is the control center of the electronic device, and connects various parts of the entire device through various interfaces and lines.

[0106] The memory can be used to store the computer program. By running or executing the computer program stored in the memory, and by invoking the data stored in the memory, the processor realizes various functions of the electronic device.

[0107] The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as a hard disk, memory, plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage devices.

[0108] The embodiments of the present application also provide a storage medium. The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be realized. Among them, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0109] The embodiment of the present application also provides a computer program product, including: a computer program or instruction, when the computer program or instruction runs on a computer, enabling the computer to execute the method of any of the above possible implementation manners.

[0110] The above is the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present application.

Claims

1. A magnetic susceptibility sounding method, characterized in that: The method comprises: Observe mutually orthogonal horizontal magnetic fields at the measuring station, the first base station and the second base station respectively, and obtain a time-aligned measuring station magnetic field time series, a first base station magnetic field time series and a second base station magnetic field time series; Performing power spectrum statistical estimation on the magnetic field time series of the measuring station, the magnetic field time series of the first base station, and the magnetic field time series of the second base station to obtain a first magnetic field mutual power spectrum between the first base station and the second base station, a second magnetic field mutual power spectrum between the measuring station and the first base station, and a third magnetic field mutual power spectrum between the measuring station and the second base station, wherein the first magnetic field mutual power spectrum, the second magnetic field mutual power spectrum, and the third magnetic field mutual power spectrum are represented by frequency; calculating the relative magnetization difference between the measuring station and the first base station and the second base station according to the first magnetic field mutual power spectrum, the second magnetic field mutual power spectrum and the third magnetic field mutual power spectrum; and According to the different skin depths corresponding to the different frequencies and in combination with the relative magnetization difference, magnetic difference data at different skin depths are obtained to complete the magnetic susceptibility depth measurement.

2. The method according to claim 1, characterized in that The relative magnetization differences between the measuring station and the first base station and the second base station are calculated according to the first magnetic field mutual power spectrum, the second magnetic field mutual power spectrum and the third magnetic field mutual power spectrum, specifically: The relative magnetization difference ε in the x direction of the horizontal magnetic field is calculated according to the following formula x (f) and the relative magnetization difference ε in the y direction y (f): Where a represents the measuring station, b represents the first base station, c represents the second base station, f represents the frequency, P xab (f) is the x-direction mutual power spectrum of the second magnetic field, P xac (f) is the x-direction mutual power spectrum of the third magnetic field, P xbc (f) is the first magnetic field x-direction mutual power spectrum, P yab (f) is the y-direction mutual power spectrum of the second magnetic field, P yac (f) is the y-direction mutual power spectrum of the third magnetic field, P ybc (f) is the mutual power spectrum of the first magnetic field in the y direction, Re[] represents the real part of the complex number.

3. The method according to claim 2, characterized in that The first magnetic field x-direction mutual power spectrum, the first magnetic field y-direction mutual power spectrum, the second magnetic field x-direction mutual power spectrum, the second magnetic field y-direction mutual power spectrum, the third magnetic field x-direction mutual power spectrum, and the third magnetic field y-direction mutual power spectrum are obtained by the following calculation formulas: P xab (f)=F{H xa (t)}·F{H xb (t)} * ,P yab (f)=F{H ya (t)}·F{H yb (t)} * P xac (f)=F{H xa (t)}·F{H xc (t)} * ,P yac (f)=F{H ya (t)}·F{H yc (t)} * P xbc (f)=F{H xb (t)}·F{H xc (t)} * ,P ybc (f)=F{H yb (t)}·F{H yc (t)} * Where F represents Fourier transform, * represents complex conjugate, t represents time, H xa (t), H ya (t) represent the x-direction time series and y-direction time series of the magnetic field at the measuring station, respectively. H xb (t), H yb (t) respectively represent the x-direction time series of the magnetic field of the first base station and the y-direction time series of the magnetic field of the first base station, H xc (t), H yc (t) respectively represent the x-direction time series of the magnetic field of the second base station and the y-direction time series of the magnetic field of the second base station. The cross-power spectrum result is a complex number, including amplitude and phase information.

4. The method according to claim 1, characterized in that The first base station and the second base station are selected in places without electromagnetic interference and where the magnetic properties of rocks and minerals are relatively weak relative to the target body, and the distance between the first base station and the second base station, the distance between the first base station and the measuring station, and the distance between the second base station and the measuring station are greater than 3 times the noise source influence radius, and the measuring station, the first base station and the second base station are simultaneously in the same area field source coverage range, ensuring that the signals among the measuring station, the first base station and the second base station are correlated but the noises are uncorrelated.

5. The method according to claim 2, characterized in that The formula for calculating skin depth is: Where ρ is the resistivity.

6. The method according to claim 5, characterized in that The resistivity ρ is obtained based on the magnetic field remote reference magnetotelluric algorithm.

7. A magnetic susceptibility sounding device, characterized in that: The device comprises: An acquisition unit is used to observe mutually orthogonal horizontal magnetic fields at the measuring station, the first base station and the second base station respectively, and obtain a time-aligned measuring station magnetic field time series, a first base station magnetic field time series and a second base station magnetic field time series; an estimating unit, configured to perform power spectrum statistical estimation on the magnetic field time series of the measuring station, the magnetic field time series of the first base station, and the magnetic field time series of the second base station, to obtain a first magnetic field mutual power spectrum between the first base station and the second base station, a second magnetic field mutual power spectrum between the measuring station and the first base station, and a third magnetic field mutual power spectrum between the measuring station and the second base station, wherein the first magnetic field mutual power spectrum, the second magnetic field mutual power spectrum, and the third magnetic field mutual power spectrum are represented by frequencies; a calculation unit, configured to calculate the relative magnetization difference between the measuring station and the first base station and the second base station according to the first magnetic field mutual power spectrum, the second magnetic field mutual power spectrum and the third magnetic field mutual power spectrum; and The depth measurement unit is used to obtain magnetic difference data of different skin depths according to different skin depths corresponding to different frequencies in combination with the relative magnetization difference, so as to complete the magnetic susceptibility depth measurement.

8. An electronic device, characterized in that: The electronic device comprises: a processor, and a memory coupled to the processor, The memory is used to store a computer program; and The processor is used to execute the computer program stored in the memory, so that the electronic device executes the method as claimed in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a computer program or instructions. When the computer program or instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The computer program product comprises: a computer program or instructions, and when the computer program or instructions are run on a computer, the computer is caused to execute the method according to any one of claims 1 to 6.

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