Source region electromagnetic pulse waveform construction method, system, medium and equipment

Abstract

The invention discloses a source region electromagnetic pulse waveform construction method and system, a medium and equipment, and relates to the technical field of data processing, and the method comprises the steps: obtaining far region data through a receiving station with a very low frequency electromagnetic pulse signal monitoring function; preprocessing the far region data to obtain a preprocessed far region waveform; calculating a decay result of single frequency point propagation between the source region and the far region through a preset long wave propagation model; constructing a channel attenuation model according to the decay result, and correcting the channel attenuation model; reversely superposing the far region waveform into the channel attenuation model to obtain source region information, and performing waveform synthesis according to the source region information to obtain a source region waveform; and post-processing the source region waveform to obtain a source region very-low-frequency electromagnetic pulse waveform. According to the method, the reverse source region waveform modeling work is carried out by adopting the actually measured far-region very-low-frequency electromagnetic pulse data and the long-wave propagation model, so that the accuracy of source region waveform modeling is improved.

Description

Technical Field

[0001] The present invention relates to the field of data processing technology, and in particular to a method, system, medium and equipment for constructing a source region electromagnetic pulse waveform. Background Art

[0002] Lightning and nuclear explosions can cause instantaneous strong electromagnetic pulses, which may cause great damage to various systems and infrastructures that rely on electronic equipment, such as electricity, transportation, communications, and navigation positioning. Electromagnetic pulse simulation research is an important way for people to understand and prevent electromagnetic pulses. Electromagnetic pulse simulation mainly includes source area signal modeling and propagation attenuation simulation. The accuracy of the source area signal has a great influence on the simulation calculation of electromagnetic pulse propagation.

[0003] Currently, the only available source electromagnetic pulse signals are public standard waveforms. However, when the standard waveforms are used to simulate the far-field propagation of individual electromagnetic pulses, they are often very different from the actual observed waveforms. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method, system, medium and equipment for constructing a source region electromagnetic pulse waveform, aiming to solve the problem that the source region standard waveform in the existing electromagnetic pulse far-zone propagation simulation calculation cannot accurately reflect the individual source region characteristics, thereby improving the accuracy of electromagnetic pulse far-zone propagation simulation.

[0005] A first aspect of the present invention is to provide a method for constructing a source region electromagnetic pulse waveform, the method comprising: Acquire remote area data through receiving stations with electromagnetic pulse signal monitoring function; Preprocessing the far-zone data to obtain a preprocessed far-zone waveform; The attenuation result of single frequency point propagation between the source area and the far area is calculated through the preset long wave propagation model; Constructing a channel attenuation model according to the attenuation result, and correcting the channel attenuation model; The far-zone waveform is reversely superimposed on the channel attenuation model to obtain field strength and phase information of different frequency points in the source area, and waveform synthesis is performed according to the field strength and phase information of the frequency points in the source area to obtain the source area waveform; The source region waveform is post-processed to obtain a source region very low frequency electromagnetic pulse waveform.

[0006] According to one aspect of the above technical solution, the step of calculating the attenuation result of single frequency point propagation between the source area and the far area through a preset long wave propagation model includes: Determine the source point coordinates and the target point coordinates respectively, and calculate the propagation distance and azimuth between the source point coordinates and the target point coordinates; According to the source point coordinates, propagation distance and azimuth, draw an attenuation route for the waveform to reach the target point coordinates fastest in a preset earth model; Writing the source region coordinates and azimuth angle into an execution case of a long wave propagation model, setting a frequency value in the execution case, determining a maximum propagation distance, and defining a distance step; Multiple single frequency points within a preset frequency range are cyclically calculated to obtain single frequency data to determine the amplitude tensor and phase tensor of the waveform during the decay process.

[0007] According to one aspect of the above technical solution, the process of cyclically calculating multiple single frequency points within a preset frequency range is specifically as follows: The single frequency data of a total of 58 single frequency points between 3-60kHz are calculated cyclically.

[0008] According to one aspect of the above technical solution, the expression of the channel attenuation model is: ; In the formula, for The amplitude tensor in , for The phase tensor in .

[0009] According to one aspect of the above technical solution, the step of correcting the channel attenuation model includes: The channel attenuation model is corrected by using a hample filter function and a smooth smoothing function.

[0010] According to one aspect of the above technical solution, the step of synthesizing waveforms according to the source area information to obtain source area waveforms is performed according to the following expression: ; ; ; In the formula, is the waveform data length, is the far-zone time domain waveform, is the far-zone frequency domain data, is an imaginary unit, is the frequency domain data of the source region, , They are discrete points in the time domain and discrete points in the frequency domain respectively.

[0011] According to one aspect of the above technical solution, the step of post-processing the source region waveform to obtain the source region very low frequency electromagnetic pulse waveform includes: De-noising the source region waveform to obtain theoretical modeling data; Calculating the data mean and standard deviation based on the theoretical modeling data, indexing and querying the time domain waveforms below a preset standard deviation threshold, so as to construct a source region very low frequency electromagnetic pulse waveform based on the index results; The calculation expression of the data mean is: ; The calculation expression of the data standard deviation is: .

[0012] The second aspect of the present invention is to provide a source region electromagnetic pulse waveform construction system, which is applied to the method described in the above technical solution, and the system comprises: A data acquisition module, used to acquire remote area data through a receiving station with an electromagnetic pulse signal monitoring function; A pre-processing module, used for pre-processing the far-zone data to obtain a pre-processed far-zone waveform; A calculation module, used to calculate the attenuation result of single frequency point propagation between the source area and the far area through a preset long wave propagation model; A model building module, used to build a channel attenuation model according to the attenuation result, and to modify the channel attenuation model; A waveform synthesis module, used for reversely superimposing the far-zone waveform into the channel attenuation model to obtain source area information, and performing waveform synthesis according to the source area information to obtain a source area waveform; The post-processing module is used to post-process the source region waveform to obtain a source region very low frequency electromagnetic pulse waveform.

[0013] The third aspect of the present invention is to provide a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the above technical solution.

[0014] The fourth aspect of the present invention is to provide a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the above technical solution when executing the computer program.

[0015] Compared with the prior art, the source region electromagnetic pulse waveform construction method, system, medium and device shown in the present invention have the following beneficial effects: In the process of constructing the source area very low frequency electromagnetic pulse waveform, the far area data is obtained through a receiving station with a very low frequency electromagnetic pulse signal monitoring function, and the far area data is filtered by a pre-processing method, and then the decay result of the single frequency point propagation between the source area and the far area is calculated by a preset long wave propagation model, and a channel attenuation model is constructed based on this, and then the far area waveform is reversely superimposed on the channel attenuation model to obtain the source area information, and then waveform synthesis is performed according to the source area information to obtain the source area waveform, and finally the source area waveform is post-processed to finally obtain the source area very low frequency electromagnetic pulse waveform. The present invention uses the measured far area very low frequency electromagnetic pulse data and the long wave propagation model to perform reverse source area waveform modeling, and finally different source area modeling results can be obtained for events with different characteristics when modeling the source area waveform, thereby improving the accuracy of source area waveform modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 It is a schematic diagram of the flow of a method for constructing a source region electromagnetic pulse waveform in one embodiment of the present invention; Figure 2 It is a structural block diagram of a source region electromagnetic pulse waveform construction system in one embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0018] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0020] Embodiment 1 See also Figure 1 The first embodiment of the present invention provides a method for constructing a source region electromagnetic pulse waveform, the method comprising steps S10 to S60: Step S10, acquiring far-field data through a receiving station with a very low frequency electromagnetic pulse signal monitoring function.

[0021] Since the main frequency of the far-zone electromagnetic pulse waveform is usually 10-30kHz, the source area electromagnetic pulse construction proposed by the method shown in this embodiment is also mainly aimed at the very low frequency / low frequency band, usually 3-60kHz. Because the main frequency is in the very low frequency band, it is also usually called a very low frequency electromagnetic pulse.

[0022] Specifically, due to the need for detailed modeling, far-field data needs to be obtained from receiving stations that monitor very low frequency electromagnetic pulse signals, and in order to verify accuracy, two or more receiving stations in different directions are usually required to obtain far-field data separately. Since very low frequency electromagnetic pulse propagation has obvious path differences, the large circle propagation path connecting the selected far-field points and the source area position needs to form a certain separation angle. If the far-field stations are on the same large circle propagation path, the robustness of the source area waveform cannot be reflected when analyzing the correctness of the modeling results.

[0023] Step S20, preprocessing the far-zone data to obtain a preprocessed far-zone waveform.

[0024] Specifically, in long-distance propagation, signals in the very low frequency band have low losses and long propagation distances in waveguide mode propagation. In this embodiment, it is necessary to first ensure the availability of far-zone data, and use low-pass filtering to eliminate the influence of data with a frequency higher than 60kHz. Secondly, the effective waveform is fixed within the range of 1ms. The effective waveform is a complete pulse waveform, in which the sampling resolution can generally be set to 0.5μs. If the original resolution does not meet the 0.5μs resolution, if the resolution is different from the set value, the original waveform can be sampled or interpolated to make its time resolution equal to the set value, such as 0.5μs. The measured far-zone waveform used for source area modeling in the present invention adopts the following common settings: an input waveform with a time length of 1ms, a sampling rate of 2MHz, and a resolution of 0.5μs, denoted as Dw.

[0025] Step S30, calculating the attenuation result of single frequency point propagation between the source area and the far area through a preset long wave propagation model.

[0026] First of all, it should be noted that the preset long-wave propagation model adopts the LWPC model (Long-Wavelength Propagation Capability). Since LWPC can calculate the decay process of a given single frequency point and does not involve the shape of the time domain waveform in the source area, it is used here to calculate the decay result of a single frequency point propagating from the source area to the far area using the waveguide mode method.

[0027] In this embodiment, the step of calculating the attenuation result of single frequency point propagation between the source area and the far area by using a preset long wave propagation model includes: Determine the source point coordinates and the target point coordinates respectively, and calculate the propagation distance and azimuth between the source point coordinates and the target point coordinates; According to the source point coordinates, propagation distance and azimuth, draw an attenuation route for the waveform to reach the target point coordinates fastest in a preset earth model; Writing the source region coordinates and azimuth angle into an execution case of a long wave propagation model, setting a frequency value in the execution case, determining a maximum propagation distance, and defining a distance step; Multiple single frequency points within a preset frequency range are cyclically calculated to obtain single frequency data to determine the amplitude tensor and phase tensor of the waveform during the decay process.

[0028] Specifically, the steps include: calculating the propagation distance and azimuth, and writing LWPC entry use cases.

[0029] Among them, the process of calculating the propagation distance and azimuth specifically includes: determining the coordinates of the source point and the target point, calculating the distance between the two points (in km), and calculating the azimuth between the two points. Through the three elements of the source point coordinates, azimuth, and propagation distance, a great circle line is drawn on the earth model. This great circle line is the fastest attenuation route for the waveform to reach the far area.

[0030] In addition, the process of writing LWPC entry use cases specifically includes: writing the far zone coordinates and azimuth angles into the LWPC execution use case, setting the frequency value to be calculated, determining the maximum propagation distance (no more than 15,000 km), defining the calculation distance step (100 km), and the source time expressed in universal time. Then the calculation is performed cyclically to complete a total of 58 single frequency points between 3-60 kHz.

[0031] After calculating the single-frequency data, use an N-order tensor to save the decay amplitude and phase of each frequency band at different distance steps. N is the number of frequency bands that have been calculated. This third-order tensor is denoted as M.

[0032] Step S40: construct a channel attenuation model according to the attenuation result, and modify the channel attenuation model.

[0033] In this embodiment, the expression of the channel attenuation model is:

[0034] In the formula, for The amplitude tensor in , for The phase tensor in .

[0035] In this embodiment, the constructed Model channel attenuation model needs to be corrected to a certain extent. Specifically, the model is corrected through the hample filtering function and the smooth smoothing function. The purpose is to remove abnormal wild points and smooth the decay characteristics, reduce the decay gap between each frequency point, and thus improve the generalization ability of the source area waveform corrected by the model.

[0036] Step S50, reversely superimposing the far-zone waveform into the channel attenuation model to obtain source zone information, and performing waveform synthesis according to the source zone information to obtain a source zone waveform.

[0037] In this embodiment, the step of synthesizing waveforms according to the source region information to obtain source region waveforms is performed according to the following expression: ; ; ; In the formula, is the waveform data length, is the far-zone time domain waveform, is the far-zone frequency domain data, is an imaginary unit, is the frequency domain data of the source region, , They are discrete points in the time domain and discrete points in the frequency domain respectively.

[0038] Specifically, after obtaining the channel information of the source region decaying to the far region, in this embodiment, the far region signal is reversely superimposed on the above channel attenuation model to obtain the source region information, that is, the source region waveform.

[0039] Step S60, post-processing the source region waveform to obtain a source region very low frequency electromagnetic pulse waveform.

[0040] In this embodiment, since there are still noise points in the modeled data, it is necessary to complete the denoising process in this step to obtain the theoretical modeling data. By calculating the data mean and standard deviation, the standard deviation threshold T is set as needed in this embodiment, and the time domain waveform index below the standard deviation threshold is queried, where the calculation formula of the data mean is: ; The calculation formula for the data standard deviation is: .

[0041] Compared with the prior art, the source region electromagnetic pulse waveform construction method shown in this embodiment has the following beneficial effects: In the process of constructing the source area very low frequency electromagnetic pulse waveform, the far area data is obtained through a receiving station with a very low frequency electromagnetic pulse signal monitoring function, and the far area data is filtered by a pre-processing method, and then the attenuation result of the single frequency point propagation between the source area and the far area is calculated by a preset long wave propagation model, and a channel attenuation model is constructed based on this, and then the far area waveform is reversely superimposed on the channel attenuation model to obtain the source area information, and then waveform synthesis is performed according to the source area information to obtain the source area waveform, and finally the source area waveform is post-processed to finally obtain the source area very low frequency electromagnetic pulse waveform. This embodiment uses the measured far area very low frequency electromagnetic pulse data and the long wave propagation model to perform reverse source area waveform modeling, and finally different source area modeling results can be obtained for events with different characteristics when modeling the source area waveform, thereby improving the accuracy of source area waveform modeling.

[0042] Embodiment 2 See also Figure 2 The second embodiment of the present invention provides a source region electromagnetic pulse waveform construction system, which is applied to the method described in the first embodiment above, and the system includes: The data acquisition module 10 is used to acquire remote area data through a receiving station with a very low frequency electromagnetic pulse signal monitoring function.

[0043] Specifically, due to the need for detailed modeling, far-field data needs to be obtained from receiving stations that monitor very low frequency electromagnetic pulse signals, and in order to verify accuracy, two or more receiving stations in different directions are usually required to obtain far-field data separately. Since very low frequency electromagnetic pulse propagation has obvious path differences, the large circle propagation path connecting the selected far-field points and the source area position needs to form a certain separation angle. If the far-field stations are on the same large circle propagation path, the robustness of the source area waveform cannot be reflected when analyzing the correctness of the modeling results.

[0044] The pre-processing module 20 is used to pre-process the far-zone data to obtain a pre-processed far-zone waveform.

[0045] Specifically, in long-distance propagation, signals in the very low frequency band have low losses and long propagation distances in waveguide mode propagation. In this embodiment, it is necessary to first ensure the availability of far-zone data, and use low-pass filtering to eliminate the influence of data with a frequency higher than 60kHz. Secondly, the effective waveform is fixed within the range of 1ms. The effective waveform is a complete pulse waveform, in which the sampling resolution can generally be set to 0.5μs. If the original resolution does not meet the 0.5μs resolution, if the resolution is different from the set value, the original waveform can be sampled or interpolated to make its time resolution equal to the set value, such as 0.5μs. The measured far-zone waveform used for source area modeling in the present invention adopts the following common settings: an input waveform with a time length of 1ms, a sampling rate of 2MHz, and a resolution of 0.5μs, denoted as Dw.

[0046] The calculation module 30 is used to calculate the attenuation result of single frequency point propagation between the source area and the far area through a preset long wave propagation model.

[0047] First of all, it should be noted that the preset long-wave propagation model adopts the LWPC model (Long-Wavelength Propagation Capability). Since LWPC can calculate the decay process of a given single frequency point and does not involve the shape of the time domain waveform in the source area, it is used here to calculate the decay result of a single frequency point propagating from the source area to the far area using the waveguide mode method.

[0048] In this embodiment, the calculation module 30 is specifically used for: Determine the source point coordinates and the target point coordinates respectively, and calculate the propagation distance and azimuth between the source point coordinates and the target point coordinates; According to the source point coordinates, propagation distance and azimuth, draw an attenuation route for the waveform to reach the target point coordinates fastest in a preset earth model; Writing the source region coordinates and azimuth angle into an execution case of a long wave propagation model, setting a frequency value in the execution case, determining a maximum propagation distance, and defining a distance step; Multiple single frequency points within a preset frequency range are cyclically calculated to obtain single frequency data to determine the amplitude tensor and phase tensor of the waveform during the decay process.

[0049] Specifically, the steps include: calculating the propagation distance and azimuth, and writing LWPC entry use cases.

[0050] Among them, the process of calculating the propagation distance and azimuth specifically includes: determining the coordinates of the source point and the target point, calculating the distance between the two points (in km), and calculating the azimuth between the two points. Through the three elements of the source point coordinates, azimuth, and propagation distance, a great circle line is drawn on the earth model. This great circle line is the fastest attenuation route for the waveform to reach the far area.

[0051] In addition, the process of writing LWPC entry use cases specifically includes: writing the far zone coordinates and azimuth angles into the LWPC execution use case, setting the frequency value to be calculated, determining the maximum propagation distance (no more than 15,000 km), defining the calculation distance step (100 km), and the world time when the propagation occurs. Then the calculation is performed cyclically to complete a total of 58 single frequency points between 3-60 kHz.

[0052] After calculating the single-frequency data, use an N-order tensor to save the decay amplitude and phase of each frequency band at different distance steps. N is the number of frequency bands that have been calculated. This third-order tensor is denoted as M.

[0053] The model building module 40 is used to build a channel attenuation model according to the attenuation result and to modify the channel attenuation model.

[0054] In this embodiment, the expression of the channel attenuation model is:

[0055] In the formula, for The amplitude tensor in , for The phase tensor in .

[0056] In this embodiment, the constructed Model channel attenuation model needs to be corrected to a certain extent. Specifically, the model is corrected through the hample filtering function and the smooth smoothing function. The purpose is to remove abnormal wild points and smooth the decay characteristics, reduce the decay gap between each frequency point, and thus improve the generalization ability of the source area waveform corrected by the model.

[0057] The waveform synthesis module 50 is used to reversely superimpose the far-zone waveform into the channel attenuation model to obtain source area information, and perform waveform synthesis according to the source area information to obtain the source area waveform.

[0058] In this embodiment, the step of synthesizing waveforms according to the source region information to obtain source region waveforms is performed according to the following expression: ; ; ; In the formula, is the waveform data length, is the far-zone time domain waveform, is the far-zone frequency domain data, is an imaginary unit, is the frequency domain data of the source region, , They are discrete points in the time domain and discrete points in the frequency domain respectively.

[0059] Specifically, after obtaining the channel information of the source region decaying to the far region, in this embodiment, the far region signal is reversely superimposed on the above channel attenuation model to obtain the source region information, that is, the source region waveform.

[0060] The post-processing module 60 is used to post-process the source region waveform to obtain a source region very low frequency electromagnetic pulse waveform.

[0061] In this embodiment, since there are still noise points in the modeled data, it is necessary to complete the denoising process in this step to obtain the theoretical modeling data. By calculating the data mean and standard deviation, the standard deviation threshold T is set as needed in this embodiment, and the time domain waveform index below the standard deviation threshold is queried, where the calculation formula of the data mean is: ; The calculation formula for the data standard deviation is: .

[0062] Compared with the prior art, the system constructed by using the source region electromagnetic pulse waveform shown in this embodiment has the following beneficial effects: In the process of constructing the source area very low frequency electromagnetic pulse waveform, the far area data is obtained through a receiving station with a very low frequency electromagnetic pulse signal monitoring function, and the far area data is filtered by a pre-processing method, and then the decay result of the single frequency point propagation between the source area and the far area is calculated by a preset long wave propagation model, and a channel attenuation model is constructed based on this, and then the far area waveform is reversely superimposed on the channel attenuation model to obtain the source area information, and then waveform synthesis is performed according to the source area information to obtain the source area waveform, and finally the source area waveform is post-processed to finally obtain the source area very low frequency electromagnetic pulse waveform. The present invention uses the measured far area very low frequency electromagnetic pulse data and the long wave propagation model to perform reverse source area waveform modeling, and finally when modeling the source area waveform, different source area modeling results can be obtained for events with different characteristics, thereby improving the accuracy of source area waveform modeling.

[0063] Embodiment 3 A third embodiment of the present invention provides a readable storage medium having a computer program stored thereon, which implements the steps of the method described in the above embodiment when executed by a processor.

[0064] Embodiment 4 A fourth embodiment of the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the above embodiment when executing the computer program.

[0065] 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.

[0066] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for constructing a source region electromagnetic pulse waveform, characterized in that: The method comprises: Acquire remote area data through receiving stations with VLF electromagnetic pulse signal monitoring function; Preprocessing the far-zone data to obtain a preprocessed far-zone waveform; The attenuation result of single frequency point propagation between the source area and the far area is calculated through the preset long wave propagation model; Constructing a channel attenuation model according to the attenuation result, and correcting the channel attenuation model; Inversely superimposing the far-zone waveform onto the channel attenuation model to obtain source zone information, and performing waveform synthesis according to the source zone information to obtain a source zone waveform; The source region waveform is post-processed to obtain a source region very low frequency electromagnetic pulse waveform.

2. The method for constructing a source region electromagnetic pulse waveform according to claim 1, characterized in that: The step of calculating the attenuation result of single frequency point propagation between a source area and a far area by using a preset long wave propagation model comprises: Determine the source point coordinates and the target point coordinates respectively, and calculate the propagation distance and azimuth between the source point coordinates and the target point coordinates; According to the source point coordinates, propagation distance and azimuth, draw an attenuation route for the waveform to reach the target point coordinates fastest in a preset earth model; Writing the source region coordinates and azimuth angle into an execution case of a long wave propagation model, setting a frequency value in the execution case, determining a maximum propagation distance, and defining a distance step; Multiple single frequency points within a preset frequency range are cyclically calculated to obtain single frequency data to determine the amplitude tensor and phase tensor of the waveform during the decay process.

3. The method for constructing a source region electromagnetic pulse waveform according to claim 2, characterized in that: The process of cyclically calculating multiple single frequency points within a preset frequency range is as follows: The single frequency data of a total of 58 single frequency points between 3-60kHz are calculated cyclically.

4. The method for constructing a source region electromagnetic pulse waveform according to claim 1, characterized in that: The expression of the channel attenuation model is: ； In the formula, for The amplitude tensor in , for The phase tensor in .

5. The method for constructing a source region electromagnetic pulse waveform according to claim 4, characterized in that: The step of correcting the channel attenuation model comprises: The channel attenuation model is corrected by using a hample filter function and a smooth smoothing function.

6. The method for constructing a source region electromagnetic pulse waveform according to claim 1, characterized in that: The step of synthesizing waveforms according to the source region information to obtain source region waveforms is performed according to the following expression: ； ； ； In the formula, is the waveform data length, is the far-zone time domain waveform, is the far-zone frequency domain data, is an imaginary unit, is the frequency domain data of the source region, , They are discrete points in the time domain and discrete points in the frequency domain respectively.

7. The method for constructing a source region electromagnetic pulse waveform according to claim 6, characterized in that: The step of post-processing the source region waveform to obtain a source region very low frequency electromagnetic pulse waveform comprises: De-noising the source region waveform to obtain theoretical modeling data; Calculating the data mean and standard deviation based on the theoretical modeling data, indexing and querying the time domain waveforms below a preset standard deviation threshold, so as to construct a source region very low frequency electromagnetic pulse waveform based on the index results; The calculation expression of the data mean is: ； The calculation expression of the data standard deviation is: 。 8. A source region electromagnetic pulse waveform construction system, characterized in that: The method applied to any one of claims 1 to 7, wherein the system comprises: A data acquisition module, used to acquire remote area data through a receiving station with a very low frequency electromagnetic pulse signal monitoring function; A pre-processing module, used for pre-processing the far-zone data to obtain a pre-processed far-zone waveform; A calculation module, used to calculate the attenuation result of single frequency point propagation between the source area and the far area through a preset long wave propagation model; A model building module, used to build a channel attenuation model according to the attenuation result, and to modify the channel attenuation model; A waveform synthesis module, used for reversely superimposing the far-zone waveform into the channel attenuation model to obtain source area information, and performing waveform synthesis according to the source area information to obtain a source area waveform; The post-processing module is used to post-process the source region waveform to obtain a source region very low frequency electromagnetic pulse waveform.

9. A readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

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