Method and device for extracting marine magnetic anomaly bands under the interference of magmatic activity

Abstract

The present invention discloses a method and device for extracting marine magnetic anomaly strips under the interference of magmatic activity, belonging to the technical field of marine magnetism. The method comprises performing two-dimensional Fourier transform on target magnetic anomaly strip data to obtain target magnetic anomaly strip data in the frequency domain, wherein the target magnetic anomaly strip data is marine magnetic anomaly strip data under the interference of magma; performing anisotropic filtering on the target magnetic anomaly strip data in the frequency domain by using an anisotropic filter to obtain the filtering result in the frequency domain; performing two-dimensional Fourier inverse transform on the filtering result in the frequency domain to obtain the magnetic anomaly strip extraction result in the space domain. The present invention realizes the effective extraction of marine magnetic anomaly strips under the interference of magmatic activity, reduces the interference of magnetic anomalies of magmatic activity, and improves the accuracy of interpretation of marine magnetic anomaly strips.

Description

Technical Field

[0001] The invention relates to the technical field of marine magnetism, and in particular to a method and a device for extracting marine magnetic anomaly bands under the interference of magma activity. Background Art

[0002] Marine magnetic anomaly bands are formed by the intensity changes of the geomagnetic field recorded by thermoremanent magnetism during the formation of the oceanic crust, and contain rich information on the structure of the oceanic crust and the reversal of the geomagnetic field. By identifying the magnetic anomaly bands, information on the age and expansion process of the ocean basin can be provided, providing rich geological information for marine oil and gas exploration. However, the actual marine magnetic anomaly bands are often disturbed by magmatic activities, including seamounts protruding from the seafloor and magmatic intrusions that are not exposed on the seafloor, which are formed during or after the seafloor expansion. The magnetic anomalies generated by magmatic activities are randomly distributed spot-like closures superimposed on the magnetic anomaly bands, causing the magnetic anomaly bands to be discontinuous and locally distorted, which brings difficulties to the interpretation of the magnetic anomaly bands.

[0003] In the related art, the invention patent application with publication number CN 108490494 A discloses a method for suppressing ocean magnetic noise based on spectral subtraction and wavelet analysis, and the implementation steps include: step S1, establishing an ocean wave magnetic field model; step S2, performing spectral subtraction and denoising on the magnetic anomaly detection signal with ocean wave magnetic field noise; step S3, determining the decomposition level, and performing wavelet analysis on the processed signal. Therefore, this method uses spectral subtraction, wavelet analysis decomposition and reconstruction to suppress and process ocean wave noise and improve the signal-to-noise ratio, but it is not suitable for processing ocean magnetic anomaly strips under the interference of magmatic activity.

[0004] In summary, there is currently no effective method to extract marine magnetic anomaly bands under the interference of magmatic activity. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to effectively extract the marine magnetic anomaly bands under the interference of magma activity.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] On the one hand, the present invention provides a method for extracting marine magnetic anomaly bands under the interference of magmatic activity, the method comprising:

[0008] Performing a two-dimensional Fourier transform on the target magnetic anomaly strip data in the spatial domain to obtain the target magnetic anomaly strip data in the frequency domain, wherein the target magnetic anomaly strip data is the marine magnetic anomaly strip data under magma interference;

[0009] Anisotropic filtering is performed on the target magnetic anomaly strip data in the frequency domain using an anisotropic filter to obtain a frequency domain filtering result;

[0010] Performing a two-dimensional inverse Fourier transform on the frequency domain filtering result to obtain a magnetic anomaly strip extraction result in the spatial domain;

[0011] Wherein, the anisotropic filter f(u,v) is expressed as:

[0012]

[0013] Wherein, Δu and Δv are the major axis length and minor axis length of the anisotropic filter, respectively, and u and v are the wave numbers in the x-axis direction and the y-axis direction in the spatial domain corresponding to the frequency domain, respectively.

[0014] The present invention converts the marine magnetic anomaly strip data under magma interference into the frequency domain through two-dimensional Fourier transform, analyzes the anisotropy of the magnetic anomaly data under the frequency domain rate, and finds that the frequency spectrum of the magnetic anomaly strip is concentrated in the direction perpendicular to the magnetic anomaly strip, while the isotropic annular frequency spectrum is randomly distributed due to the interference of magma activity. The designed anisotropic filter utilizes this characteristic of the frequency domain to perform anisotropic filtering on the target magnetic anomaly strip under the frequency domain, allowing the frequency spectrum components of the marine magnetic anomaly strip to pass through while filtering out the frequency components of the magnetic anomaly interfered by magma activity. The effective extraction of the marine magnetic anomaly strip under the interference of magma activity is achieved, the interference of the magnetic anomaly of magma activity is reduced, and the accuracy of the interpretation of the marine magnetic anomaly strip is improved.

[0015] Furthermore, the method further comprises:

[0016] Rotating the anisotropic filter so that the long axis direction of the frequency domain anisotropic filter is perpendicular to the direction of the target magnetic anomaly strip data in the spatial domain;

[0017] Wherein, the coordinates of the rotated anisotropic filter are expressed as:

[0018]

[0019] Wherein, u', v' are the wave numbers of the anisotropic filter in the frequency domain after rotation, u, v are the wave numbers in the x-axis direction and the y-axis direction of the spatial domain corresponding to the frequency domain, and θ is the angle of rotation from the original coordinate to the new coordinate.

[0020] Furthermore, the long axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the long axis direction of the magnetic anomaly data. max ;

[0021] The length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data max .

[0022] Furthermore, the long-axis response of the anisotropic filter is an all-pass filter.

[0023] In addition, the present invention also proposes a device for extracting marine magnetic anomaly bands under the interference of magmatic activity, the device comprising:

[0024] A Fourier transform module is used to perform a two-dimensional Fourier transform on the target magnetic anomaly strip data to obtain the target magnetic anomaly strip data in the frequency domain, wherein the target magnetic anomaly strip data is the marine magnetic anomaly strip data under magma interference;

[0025] An anisotropic filtering module is used to perform anisotropic filtering on the target magnetic anomaly strip data in the frequency domain using an anisotropic filter to obtain a frequency domain filtering result;

[0026] An inverse Fourier transform module is used to perform a two-dimensional inverse Fourier transform on the frequency domain filtering result to obtain a magnetic anomaly strip extraction result in the spatial domain;

[0027] Wherein, the anisotropic filter f(u,v) is expressed as:

[0028]

[0029] Wherein, Δu and Δv are the major axis length and minor axis length of the anisotropic filter, respectively, and u and v are the wave numbers in the x-axis direction and the y-axis direction in the spatial domain corresponding to the frequency domain, respectively.

[0030] Furthermore, the device also includes:

[0031] A coordinate rotation module, used for rotating the anisotropic filter so that the long axis direction of the frequency domain anisotropic filter is perpendicular to the direction of the target magnetic anomaly strip data in the spatial domain;

[0032] Wherein, the coordinates of the rotated anisotropic filter are expressed as:

[0033]

[0034] Wherein, u', v' are the wave numbers of the anisotropic filter in the frequency domain after rotation, u, v are the wave numbers in the x-axis direction and the y-axis direction of the spatial domain corresponding to the frequency domain, and θ is the angle of rotation from the original coordinate to the new coordinate.

[0035] Furthermore, the long axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the long axis direction of the magnetic anomaly data. max ;

[0036] The length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data max .

[0037] Furthermore, the long-axis response of the anisotropic filter is an all-pass filter.

[0038] In addition, the present invention also proposes a device for extracting marine magnetic anomaly bands under the interference of magmatic activity, which includes a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the method as described above.

[0039] In addition, the present invention also proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described above is implemented.

[0040] The advantages of the present invention are:

[0041] (1) The data of marine magnetic anomaly strips under magma interference are converted to the frequency domain by two-dimensional Fourier transform. The anisotropy of the magnetic anomaly data in the frequency domain is analyzed. It can be found that the spectrum of the magnetic anomaly strips is concentrated in the direction perpendicular to the magnetic anomaly strips, while the isotropic annular spectrum is the randomly distributed spectrum of the anomaly interference of magma activity. The designed anisotropic filter utilizes this characteristic of the frequency domain to perform anisotropic filtering on the target magnetic anomaly strips in the frequency domain, allowing the spectrum components of the marine magnetic anomaly strips to pass through while filtering out the frequency components of the magnetic anomaly interference of magma activity. The effective extraction of the marine magnetic anomaly strips under the interference of magma activity is achieved, the interference of the magnetic anomaly of magma activity is reduced, and the accuracy of the interpretation of the marine magnetic anomaly strips is improved.

[0042] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic flow chart of a method for extracting marine magnetic anomaly bands under the interference of magmatic activity in one embodiment of the present invention;

[0044] Figure 2 It is the marine magnetic anomaly strip disturbed by magmatic activity in the present invention;

[0045] Figure 3 is the logarithmic power spectrum of the marine magnetic anomaly bands disturbed by magmatic activity in the present invention;

[0046] Figure 4It is the anisotropic filter for extracting magnetic anomaly strips in the frequency domain in the present invention;

[0047] Figure 5 It is the comparison between the long-axis anisotropic filter response and the normalized amplitude spectrum of magnetic anomaly in the present invention;

[0048] Figure 6 It is the comparison between the short-axis anisotropic filter response and the normalized amplitude spectrum of magnetic anomaly in the present invention;

[0049] Figure 7 It is the magnetic anomaly strip extracted in the present invention;

[0050] Figure 8 It is a schematic diagram of the structure of a device for extracting an anomaly marine magnetic strip under the interference of magma activity in one embodiment of the present invention;

[0051] Fig. 9 It is a structural schematic diagram of an ocean magnetic anomaly strip extraction device under the interference of magma activity in one embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] Reference Figure 1 An embodiment of the present invention provides a method for extracting marine magnetic anomaly bands under the interference of magmatic activity, and the method comprises the following steps:

[0054] S10, performing a two-dimensional Fourier transform on the target magnetic anomaly strip data to obtain the target magnetic anomaly strip data in the frequency domain, wherein the target magnetic anomaly strip data is the marine magnetic anomaly strip data under magma interference;

[0055] S20, using an anisotropic filter to perform anisotropic filtering on the target magnetic anomaly strip data in the frequency domain to obtain a frequency domain filtering result;

[0056] S30, performing a two-dimensional Fourier inverse transform on the frequency domain filtering result to obtain a magnetic anomaly strip extraction result in the spatial domain;

[0057] Wherein, the anisotropic filter f(u,v) is expressed as:

[0058]

[0059] Wherein, Δu and Δv are the major axis length and minor axis length of the anisotropic filter, respectively, and u and v are the wave numbers in the x-axis direction and the y-axis direction in the spatial domain corresponding to the frequency domain, respectively.

[0060] Specifically, Figure 2 It shows the marine magnetic anomaly strips disturbed by magmatic activity, in which the magnetic anomaly strips are superimposed with the interference of magmatic activity, and randomly distributed spot-like closures appear, causing the magnetic anomaly strips to be discontinuous and locally distorted.

[0061] Figure 3 The logarithmic power spectrum of the marine magnetic anomaly strips disturbed by magmatic activity is shown. The marine magnetic anomaly strips disturbed by magmatic activity are subjected to a two-dimensional Fourier transform to obtain their spectrum. The logarithmic power spectrum of the marine magnetic anomaly strips disturbed by magmatic activity is obtained by taking the logarithm of the square sum of the real and imaginary parts of the spectrum, as shown in Figure 4 It can be found that the spectrum response of the magnetic anomaly strip is concentrated in the horizontal direction perpendicular to the magnetic anomaly strip, and the spectrum response of the magnetic anomaly interference by magma is isotropically distributed in a circular shape.

[0062] This embodiment designs an anisotropic filter based on the frequency spectrum characteristics of magnetic anomaly strips and magmatic activity interfering with magnetic anomalies. The anisotropic filter performs anisotropic filtering on the magnetic anomaly strips in the frequency domain, allowing the frequency spectrum components of the marine magnetic anomaly strips to pass through, while filtering out the frequency components of the magnetic anomaly interfering with magmatic activity. The extraction of marine magnetic anomaly strips disturbed by magmatic activity is achieved, the interpretation accuracy of magnetic anomaly strips is improved, and the problem that the marine magnetic anomaly strips are disturbed by magmatic activity, discontinuity, local distortion, and difficulty in interpreting the magnetic anomaly strips is solved.

[0063] In one embodiment, the method further comprises the following steps:

[0064] Rotating the anisotropic filter so that the long axis direction of the frequency domain anisotropic filter is perpendicular to the direction of the target magnetic anomaly strip data in the spatial domain;

[0065] Wherein, the coordinates of the rotated anisotropic filter are expressed as:

[0066]

[0067] Wherein, u', v' are the wave numbers of the anisotropic filter in the frequency domain after rotation, u, v are the wave numbers in the x-axis direction and the y-axis direction of the spatial domain corresponding to the frequency domain, respectively, and θ is the angle of rotation from the original coordinate to the new coordinate, and the long axis of the anisotropic filter is rotated to an azimuth angle of 90°.

[0068] It should be noted that, because the directions of marine magnetic anomaly strips in different regions are different, for magnetic anomaly strips with different directions, this embodiment rotates the anisotropic filter so that the long axis direction of the anisotropic filter is perpendicular to the direction of the magnetic anomaly strip, and uses the rotated anisotropic filter to perform anisotropic filtering on the target magnetic anomaly strip data in the frequency domain to ensure the filtering effect.

[0069] In one embodiment, the long axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the long axis direction of the magnetic anomaly data. max ;

[0070] The length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data max .

[0071] It should be noted that, in this embodiment, when setting the parameters of the anisotropic filter, the long axis direction of the anisotropic filter is perpendicular to the direction of the magnetic anomaly stripe, and the amplitude spectrum of the magma interference magnetic anomaly stripe perpendicular to the direction of the magnetic anomaly stripe is taken and normalized so that the long axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the long axis direction of the magnetic anomaly data max , ensuring that all frequency components of the magnetic anomaly strip pass through.

[0072] Take the amplitude spectrum of the magma interference magnetic anomaly strip parallel to the magnetic anomaly strip and normalize it so that the length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data. max , to ensure that the spectral components of abnormal magma interference are filtered out.

[0073] In one embodiment, Figure 5 The comparison between the long-axis anisotropic filter and the magnetic anomaly amplitude spectrum is shown. The amplitude spectrum of the magnetic anomaly strip disturbed by magma is normalized. The long-axis response of the anisotropic filter is a full-pass filter. The long-axis Δu of the filter is 6.28 rad / km. The maximum wave number u in the long-axis direction of the magnetic anomaly data is max =6.28rad / km, ensuring that all spectra of the magnetic anomaly bands pass through.

[0074] Figure 6 The comparison between the short-axis anisotropy filter and the magnetic anomaly amplitude spectrum is shown. The amplitude spectrum of the magnetic anomaly strip disturbed by magma is normalized. The short-axis length of the anisotropy filter is Δv = 0.026 rad / km, and the maximum wave number v in the short-axis direction of the magnetic anomaly data is max =6.28rad / km, in order to filter out the spectral components of abnormal magma interference.

[0075] Figure 7The extracted magnetic anomaly strips are shown. The extracted magnetic anomaly strips are obtained by performing two-dimensional Fourier inverse transform to the spatial domain on the magnetic anomaly strips after anisotropic filtering. It can be seen that the extracted spectrum is in the form of band-shaped magnetic anomaly strips, which are distributed perpendicular to the direction of the magnetic anomaly strips, and there are no magnetic anomalies caused by annular magma interference.

[0076] In addition, refer to Figure 8 An embodiment of the present invention further provides a device for extracting marine magnetic anomaly bands under the interference of magmatic activity, the device comprising:

[0077] The Fourier transform module 10 is used to perform a two-dimensional Fourier transform on the target magnetic anomaly strip data to obtain the target magnetic anomaly strip data in the frequency domain, wherein the target magnetic anomaly strip data is the marine magnetic anomaly strip data under magma interference;

[0078] An anisotropic filtering module 20 is used to perform anisotropic filtering on the target magnetic anomaly strip data in the frequency domain using an anisotropic filter to obtain a frequency domain filtering result;

[0079] The inverse Fourier transform module 30 is used to perform a two-dimensional inverse Fourier transform on the frequency domain filtering result to obtain a magnetic anomaly strip extraction result in the space domain;

[0080] Wherein, the anisotropic filter f(u,v) is expressed as:

[0081]

[0082] Wherein, Δu and Δv are the major axis length and minor axis length of the anisotropic filter, respectively, and u and v are the wave numbers in the x-axis direction and the y-axis direction in the spatial domain corresponding to the frequency domain, respectively.

[0083] It should be noted that this embodiment uses an anisotropic filter to perform anisotropic filtering on the magnetic anomaly strips in the frequency domain, allowing the frequency spectrum components of the marine magnetic anomaly strips to pass through, while filtering out the frequency components of the magnetic anomaly disturbed by magmatic activity. This achieves the extraction of marine magnetic anomaly strips disturbed by magmatic activity, improves the interpretation accuracy of magnetic anomaly strips, and solves the problem that marine magnetic anomaly strips are disturbed by magmatic activity, causing discontinuity and local distortion, which makes it difficult to interpret the magnetic anomaly strips.

[0084] In one embodiment, the device further comprises:

[0085] A coordinate rotation module, used for rotating the anisotropic filter so that the long axis direction of the frequency domain anisotropic filter is perpendicular to the direction of the target magnetic anomaly strip data in the spatial domain;

[0086] Wherein, the coordinates of the rotated anisotropic filter are expressed as:

[0087]

[0088] Wherein, u', v' are the wave numbers of the anisotropic filter in the frequency domain after rotation, u, v are the wave numbers in the x-axis direction and the y-axis direction of the spatial domain corresponding to the frequency domain, and θ is the angle of rotation from the original coordinate to the new coordinate.

[0089] It should be noted that, because the directions of marine magnetic anomaly strips in different regions are different, for magnetic anomaly strips with different directions, this embodiment rotates the anisotropic filter so that the long axis direction of the anisotropic filter is perpendicular to the direction of the magnetic anomaly strip, and uses the rotated anisotropic filter to perform anisotropic filtering on the target magnetic anomaly strip data in the frequency domain to ensure the filtering effect.

[0090] In one embodiment, the long axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the long axis direction of the magnetic anomaly data. max ;

[0091] The length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data max .

[0092] It should be noted that, in this embodiment, when setting the parameters of the anisotropic filter, the long axis direction of the anisotropic filter is perpendicular to the direction of the magnetic anomaly stripe, and the amplitude spectrum of the magma interference magnetic anomaly stripe perpendicular to the direction of the magnetic anomaly stripe is taken and normalized so that the long axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the long axis direction of the magnetic anomaly data max , ensuring that all frequency components of the magnetic anomaly strip pass through.

[0093] Take the amplitude spectrum of the magma interference magnetic anomaly strip parallel to the magnetic anomaly strip and normalize it so that the length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data. max , to ensure that the spectral components of abnormal magma interference are filtered out.

[0094] It should be noted that other embodiments of the device for extracting marine magnetic anomaly bands under the interference of magmatic activity described in the present invention or methods for implementing the device can refer to the above-mentioned method embodiments, which will not be repeated here.

[0095] In addition, refer to Fig. 9An embodiment of the present invention further proposes a device for extracting marine magnetic anomaly bands under the interference of magmatic activity, the device comprising a processor 100, a memory 200 storing program instructions, a bus 300 and a communication interface 400, the processor 100, the communication interface 400 and the memory 200 are connected via the bus 300; the processor 100 is configured to execute the method for extracting marine magnetic anomaly bands under the interference of magmatic activity as described in the above embodiment when executing the program instructions.

[0096] The memory 200 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory. The communication connection between the system network element and at least one other network element is realized through at least one communication interface 703 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

[0097] The bus 300 may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory 200 is used to store programs, and the processor 100 executes the programs after receiving the execution instructions. The marine magnetic anomaly strip extraction program under the interference of magmatic activity disclosed in any of the embodiments of the present application may be applied to the processor 100, or implemented by the processor 100.

[0098] The processor 100 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 100. The above processor 100 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a readily available programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor to be executed, or the hardware and software modules in the decoding processor can be executed. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 200, and the processor 100 reads the information in the memory 200 and completes the steps of the above-mentioned method for extracting marine magnetic anomaly bands under the interference of magmatic activity in combination with its hardware.

[0099] In addition, an embodiment of the present invention further proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for extracting marine magnetic anomaly bands under the interference of magmatic activity as described above is implemented.

[0100] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0101] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0102] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0103] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0104] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for extracting marine magnetic anomaly bands under the interference of magmatic activity, characterized in that: The method comprises: Performing a two-dimensional Fourier transform on the target magnetic anomaly strip data to obtain the target magnetic anomaly strip data in the frequency domain, wherein the target magnetic anomaly strip data is the marine magnetic anomaly strip data under magma interference; Anisotropic filtering is performed on the target magnetic anomaly strip data in the frequency domain using an anisotropic filter to obtain a frequency domain filtering result; Performing a two-dimensional inverse Fourier transform on the frequency domain filtering result to obtain a magnetic anomaly strip extraction result in the spatial domain; Wherein, the anisotropic filter f(u,v) is expressed as: Wherein, Δu and Δv are the major axis length and minor axis length of the anisotropic filter, respectively; u and v are the wave numbers in the x-axis direction and y-axis direction of the spatial domain corresponding to the frequency domain; the major axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the major axis direction of the magnetic anomaly data. max , and the long axis response of the anisotropic filter is an all-pass filter; the length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data max .

2. The method for extracting marine magnetic anomaly bands under the interference of magmatic activity according to claim 1, characterized in that: The method further comprises: Rotating the anisotropic filter so that the long axis direction of the frequency domain anisotropic filter is perpendicular to the direction of the target magnetic anomaly strip data in the spatial domain; Wherein, the coordinates of the rotated anisotropic filter are expressed as: Wherein, u', v' are the wave numbers of the anisotropic filter in the frequency domain after rotation, u, v are the wave numbers in the x-axis direction and the y-axis direction of the spatial domain corresponding to the frequency domain, and θ is the angle of rotation from the original coordinate to the new coordinate.

3. A device for extracting marine magnetic anomaly bands under the interference of magmatic activity, characterized in that: The device comprises: A Fourier transform module is used to perform a two-dimensional Fourier transform on the target magnetic anomaly strip data to obtain the target magnetic anomaly strip data in the frequency domain, wherein the target magnetic anomaly strip data is the marine magnetic anomaly strip data under magma interference; An anisotropic filtering module is used to perform anisotropic filtering on the target magnetic anomaly strip data in the frequency domain using an anisotropic filter to obtain a frequency domain filtering result; An inverse Fourier transform module is used to perform a two-dimensional inverse Fourier transform on the frequency domain filtering result to obtain a magnetic anomaly strip extraction result in the spatial domain; Wherein, the anisotropic filter f(u,v) is expressed as: Wherein, Δu and Δv are the major axis length and minor axis length of the anisotropic filter, respectively; u and v are the wave numbers in the x-axis direction and y-axis direction of the spatial domain corresponding to the frequency domain; the major axis Δu of the anisotropic filter is greater than or equal to the maximum wave number u in the major axis direction of the magnetic anomaly data. max , and the long axis response of the anisotropic filter is an all-pass filter; the length Δv of the short axis of the anisotropic filter is less than or equal to 1 / 2 of the maximum wave number v in the short axis direction of the magnetic anomaly data max .

4. The device for extracting marine magnetic anomaly bands under the interference of magmatic activity as claimed in claim 3, characterized in that: The device also includes: A coordinate rotation module, used for rotating the anisotropic filter so that the long axis direction of the frequency domain anisotropic filter is perpendicular to the direction of the target magnetic anomaly strip data in the spatial domain; Wherein, the coordinates of the rotated anisotropic filter are expressed as: Wherein, u', v' are the wave numbers of the anisotropic filter in the frequency domain after rotation, u, v are the wave numbers in the x-axis direction and the y-axis direction of the spatial domain corresponding to the frequency domain, and θ is the angle of rotation from the original coordinate to the new coordinate.

5. A device for extracting marine magnetic anomaly bands under the interference of magmatic activity, characterized in that: The device includes a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the method according to any one of claims 1-2.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 2 is implemented.

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