Tensile-distortion-free correction method for split moving

Abstract

The invention belongs to the technical field of exploration-seismic processing interpretation, and particularly relates to a non-stretching distortion change correction method for split moving. According to the method, pre-stack seismic data to be dynamically corrected and time-speed pairs are input, the wavelength corresponding to each time-speed pair is calculated, the event center track and the dynamic correction value corresponding to each time-speed pair are calculated, dynamic correction value assignment is carried out in the half-wavelength range of the two sides of the event center, and the dynamic correction value is calculated. The method comprises the seven steps of obtaining the dynamic correction values of sampling points in other areas, splitting moving dynamic correction and outputting a non-stretching distortion change correction result, so that sampling points of an event in each seismic channel have the same dynamic correction value, and in the moving process, the sampling points before dynamic correction are split into data after dynamic correction. It is guaranteed that the amplitude of one sampling point is moved only once, and therefore stretching distortion is effectively avoided. The method makes full use of the number of effective channels for superposing the shallow and middle layers, and improves the imaging quality of the superposing shallow and middle layers.

Description

Technical Field

[0001] The invention belongs to the technical field of exploration-seismic processing and interpretation, and in particular relates to a method for correcting the non-stretching distortion of splitting and moving. Background Art

[0002] In conventional seismic data processing, in order to obtain structural information of underground interfaces, it is usually necessary to stack CMP gathers. Velocity analysis and dynamic correction processing are required before stacking. The purpose of velocity analysis is to obtain accurate seismic velocity, and then use the velocity to perform dynamic correction, flatten the event axis of the gathers and then stack. However, the conventional dynamic correction method calculates the time before dynamic correction based on the t0 time and shot offset after dynamic correction, and then obtains the amplitude through interpolation technology and directly puts it in the position after dynamic correction. This "moving method" is prone to multiple "moving" of the amplitude of the same sampling point in shallow long-channel, resulting in stretching distortion. In conventional seismic data processing, data that is stretched more than a certain proportion is usually removed. In this way, shallow seismic data is almost completely or mostly removed due to severe stretching, resulting in a reduction in the number of shallow coverage and failure to suppress noise well. In order to eliminate the stretching distortion in conventional dynamic correction, domestic and foreign scholars have begun to study new dynamic correction methods to solve the stretching distortion problem of conventional dynamic correction and retain as much long-channel seismic information as possible. Rupert et al. (1975) used the BMS method of moving the data block as a whole and summing the overlapping parts for dynamic correction. This method uses one dynamic correction amount for dynamic correction within a time window, thus avoiding the stretching distortion caused by different dynamic correction amounts. However, when the shot offset is large, it is easy to over-correct or under-correct the event axis. In addition, at the overlap of adjacent time windows, the processing method of adding the overlapping data and dividing by the number of superpositions is less effective. Lichman (1999), Cui Baowen (2007) and Shi Jian et al. (2011) used the non-stretching dynamic correction method of spectrum replacement to retain the long-path information. This method can theoretically eliminate any time difference, and due to the use of the fast Fourier transform algorithm, the entire algorithm has a high computational efficiency. However, since different events will affect each other after phase replacement, this method is often used for residual time difference correction in actual data processing. In addition, the dynamic correction of weak reflection layers will be affected by the adjacent strong reflection layers. Meng Qingsheng et al. (2007) eliminated the stretching distortion of the dynamic correction by modifying the dynamic correction velocity so that each time point of the same waveform has the same dynamic correction amount. However, it is difficult to select the appropriate time window and time shift factor in the actual data processing. Li Luming eliminated the stretching distortion by automatically detecting the vertical reflection time and velocity of the reflected wave, then calculating the reflection wave time of the offset to be corrected and moving the waveform as a whole at that time. This method requires very high accuracy of velocity analysis and is prone to miss thin layers. Zhao Bo et al. used the velocity information in the dynamic correction process to model forward, and then used filtering to eliminate the stretching distortion of the dynamic correction. This method is difficult to ensure that adjacent phase axes will not affect each other, and thin layers and weak reflection layers are easily missed. The method of superposition using parabolic Radon transform can eliminate stretching distortion. When using this method, the processor must find a suitable path in the Radon domain or automatically pick it up (the reliability is poor when there is noise). Therefore, the application of this method in industry is subject to certain restrictions.The stretch-free dynamic correction method based on the matching pursuit algorithm may have non-orthogonal projection and over-matching due to the redundancy of the wavelet library and the problems of the method itself, thus affecting the computational efficiency and dynamic correction effect. Biondi et al. (2014) adopted a multiple iteration method, performed partial correction in each iteration and used deconvolution to correct the influence of stretching. This method can reduce stretching distortion, but the conventional dynamic correction method is used in each iteration, which will still introduce stretching into the dynamic correction result. Lin Luchun et al. (2018) proposed a multi-sub-wave correction method, which effectively eliminated the stretching phenomenon. Liu Shiyou et al. (2022) regarded the stretch correction as a nonlinear optimization process and eliminated the stretching distortion phenomenon through curvelet sparse transformation. Summary of the invention

[0003] The present invention provides a split-and-move non-stretching distortion dynamic correction method, aiming to provide a method capable of eliminating the stretching distortion caused by conventional dynamic correction methods to improve the stacking effect of seismic data.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for correcting the non-stretching distortion of splitting and moving, comprising the following steps:

[0006] Step 1, input pre-stack seismic data and time-velocity pairs to be corrected;

[0007] Step 2: Calculate the wavelength corresponding to each time-velocity pair;

[0008] Step 3, calculating the event axis center trajectory and dynamic correction amount corresponding to each time-velocity pair;

[0009] Step 4: Assign the dynamic correction value within the half-wavelength range on both sides of the center of the event axis;

[0010] Step 5, obtaining the dynamic correction values ​​of the sampling points in the remaining areas;

[0011] Step 6: Disassemble and move the equipment for correction;

[0012] Step 7: Output the correction result without stretching distortion.

[0013] The method of time-speed pair in step 1 is to multiply the time sampling point by the time sampling interval to obtain the time, and the time and the corresponding speed together form a time-speed pair.

[0014] The method for calculating the wavelength corresponding to each time-speed pair in step 2 is as follows:

[0015] The first step is to use the time-velocity pair to calculate the trajectory of the event axis and intercept the data within a period of time above and below the trajectory;

[0016] Step 2: Calculate the amplitude spectrum of the data in step 1;

[0017] The third step is to smooth the amplitude spectrum;

[0018] Step 4: Calculate the wavelength using the formula λ=vf;

[0019] Where: λ is the wavelength, meters;

[0020] v is the velocity of the time-velocity pair, m / s;

[0021] f is the main frequency, Hz.

[0022] The third step of smoothing the amplitude spectrum is to set a proportional coefficient, and determine an amplitude value by multiplying the proportional coefficient and the maximum amplitude value. The amplitude value corresponds to at least two points on the amplitude spectrum, and the average of the frequencies corresponding to these points is taken as the main frequency.

[0023] The method for calculating the dynamic correction amount of the position corresponding to the time-velocity pair in step 2 is to calculate the corresponding in-phase center axis trajectory and dynamic correction amount based on the time-velocity pair, and assign the same dynamic correction amount to the range of the upper and lower half wavelengths centered on the trajectory of the in-phase axis center position.

[0024] The method for assigning the dynamic correction amount in step 4 is: according to the wavelength calculated in step 2, using the event axis center trajectory and the dynamic correction amount calculated in step 3, assigning the dynamic correction amount of the event axis in the area above and below the center of the event axis trajectory; for the sampling points above the first event axis, the dynamic correction amount is assigned to the dynamic correction amount of the first event axis, and for the sampling points below the last event axis, the dynamic correction amount is assigned to the dynamic correction amount of the last event axis.

[0025] The method for obtaining the dynamic correction values ​​of the sampling points in the remaining areas in step 5 is to obtain the dynamic correction values ​​of the remaining sampling points by interpolation.

[0026] The method for splitting the moving correction in step six is ​​based on the moving correction amount obtained in step five. For each sampling point before the moving correction, its time minus the moving correction amount is the time after the moving correction. If the time after the moving correction is not an integer multiple of the time sampling interval, the amplitude of the sampling point is split into two positions of two adjacent integer sampling time intervals after the moving correction. In the process of splitting, the energy of the sampling point is split according to the distance between the time after the moving correction and the positions of two adjacent integer sampling time intervals, and the farther the distance, the smaller the proportion.

[0027] Beneficial effects:

[0028] (1) The present invention includes seven steps: inputting pre-stack seismic data and time-velocity pairs to be corrected, calculating the wavelength corresponding to each time-velocity pair, calculating the center trajectory of the event axis corresponding to each time-velocity pair and its dynamic correction value, assigning the dynamic correction value within a half-wavelength range on both sides of the event axis center, obtaining the dynamic correction value of the sampling points in the remaining areas, splitting and moving the dynamic correction, and outputting the dynamic correction result without stretching distortion. In this way, each sampling point of an event axis in each seismic trace has the same dynamic correction value, and the moving process is to split the sampling points before the dynamic correction into the data after the dynamic correction, thereby ensuring that the amplitude of a sampling point is moved only once, thereby effectively avoiding stretching distortion.

[0029] (2) The present invention makes full use of the number of effective channels for shallow and middle layer stacking, thereby improving the imaging quality of the shallow and middle layers after stacking.

[0030] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a flow chart of the present invention.

[0033] Figure 2 This is a schematic diagram of the conventional XX contiguous three-dimensional pure wave correction superposition.

[0034] Figure 3 This is a schematic diagram of the superposition of the XX-piece three-dimensional pure wave correction of the present invention.

[0035] Figure 4 Schematic diagram of model data before dynamic correction in an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of the dynamic correction amount of the conventional dynamic correction method before dynamic correction.

[0037] Figure 6 It is a schematic diagram of the dynamic correction amount of the dynamic correction method of the present invention before dynamic correction.

[0038] Figure 7 Yes Figure 4 Schematic diagram of the results after conventional dynamic correction.

[0039] Figure 8 Yes Figure 4 A schematic diagram of the result of the non-stretching dynamic correction of the split moving of the present invention.

[0040] Fig. 9 is the result of conventional dynamic correction (attached Figure 5 ) schematic diagram of the amplitude spectrum.

[0041] Fig.10 The invention is the dynamic correction result (attached Figure 8 ) schematic diagram of the amplitude spectrum.

[0042] Fig.11 This is a CRP gather of actual data and a schematic diagram of the results after reaction correction.

[0043] Fig.12 Schematic diagram of the dynamic correction amount of the conventional dynamic correction method before dynamic correction.

[0044] Fig.13 Schematic diagram of the dynamic correction amount of the dynamic correction method of the present invention before dynamic correction.

[0045] Fig.14 It is attached Fig.11 Schematic diagram of the results after conventional dynamic correction.

[0046] Fig.15 It is attached Fig.11 A schematic diagram of the result of the non-stretching dynamic correction of the splitting and moving process according to the present invention.

[0047] Fig.16 is the result of conventional dynamic correction (attached Fig.14 ) schematic diagram of the amplitude spectrum.

[0048] Fig.17 This is the dynamic correction result of the present invention (see Fig.15 ) schematic diagram of the amplitude spectrum. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0050] Embodiment 1:

[0051] according to Figure 1 The method for correcting the non-stretching distortion of splitting and moving shown in the figure comprises the following steps:

[0052] Step 1, input pre-stack seismic data and time-velocity pairs to be corrected;

[0053] Step 2: Calculate the wavelength corresponding to each time-velocity pair;

[0054] Step 3, calculating the event axis center trajectory and dynamic correction amount corresponding to each time-velocity pair;

[0055] Step 4: Assign the dynamic correction value within the half-wavelength range on both sides of the center of the event axis;

[0056] Step 5, obtaining the dynamic correction values ​​of the sampling points in the remaining areas;

[0057] Step 6: Disassemble and move the equipment for correction;

[0058] Step 7: Output the correction result without stretching distortion.

[0059] The present invention uses seven steps to ensure that each sampling point of an event axis in each seismic channel has the same dynamic correction amount, and the moving process is to split the sampling points before the dynamic correction into the data after the dynamic correction, ensuring that the amplitude of a sampling point is moved only once, thereby effectively avoiding stretching distortion.

[0060] The present invention makes full use of the number of effective channels of shallow and middle layer stacking, and improves the imaging quality of shallow and middle layers after stacking.

[0061] Embodiment 2:

[0062] according to Figure 1 The difference between the non-stretching distortion correction method of split moving shown in the embodiment 1 is that the time-speed pair method in step 1 is to multiply the time sampling point by the time sampling interval to obtain the time, and the time and the corresponding speed together form a time-speed pair. Figure 2 The pre-stack seismic data to be corrected contains four phase axes. The corresponding input four time-velocity pairs are (325, 1980), (703, 2030), (1042, 2410), (1384, 2730). The first one represents the time sampling point, which is multiplied by the time sampling interval to get the time, and the second one is the velocity.

[0063] The method for calculating the wavelength corresponding to each time-speed pair in step 2 is as follows:

[0064] The first step is to use the time-velocity pair to calculate the trajectory of the event axis and intercept the data within a period of time above and below the trajectory;

[0065] Step 2: Calculate the amplitude spectrum of the data in step 1;

[0066] The third step is to smooth the amplitude spectrum;

[0067] Step 4: Calculate the wavelength using the formula λ=vf;

[0068] Where: λ is the wavelength, meters;

[0069] v is the velocity of the time-velocity pair, m / s;

[0070] f is the main frequency, Hz.

[0071] The third step of smoothing the amplitude spectrum is to set a proportional coefficient (such as 0.6), and determine an amplitude value by multiplying the proportional coefficient and the maximum amplitude value. The amplitude value corresponds to at least two points on the amplitude spectrum, and the average of the frequencies corresponding to these points is taken as the main frequency.

[0072] The method for calculating the dynamic correction amount of the position corresponding to the time-velocity pair in step 2 is to calculate the corresponding in-phase center axis trajectory and dynamic correction amount based on the time-velocity pair, and assign the same dynamic correction amount to the range of the upper and lower half wavelengths centered on the trajectory of the in-phase axis center position.

[0073] The method for assigning the dynamic correction amount in step 4 is: according to the wavelength calculated in step 2, using the event axis center trajectory and the dynamic correction amount calculated in step 3, assigning the dynamic correction amount of the event axis in the area above and below the center of the event axis trajectory; for the sampling points above the first event axis, the dynamic correction amount is assigned to the dynamic correction amount of the first event axis, and for the sampling points below the last event axis, the dynamic correction amount is assigned to the dynamic correction amount of the last event axis.

[0074] The method for obtaining the dynamic correction values ​​of the sampling points in the remaining areas in step 5 is to obtain the dynamic correction values ​​of the remaining sampling points by interpolation.

[0075] The method of splitting the moving dynamic correction in step 6 is based on the dynamic correction amount obtained in step 5. For each sampling point before the dynamic correction, its time minus the dynamic correction amount is the time after the dynamic correction. If the time after the dynamic correction is not an integer multiple of the time sampling interval, the amplitude of the sampling point is split into two positions of two adjacent integer sampling time intervals after the dynamic correction. In the process of splitting, the energy of the sampling point is split according to the distance between the time after the dynamic correction and the position of the two adjacent integer sampling time intervals. The farther the distance, the smaller the proportion. For example, if the time sampling interval is 1 millisecond and the time after the dynamic correction is 1228.2 milliseconds, the two adjacent integer sampling time intervals are 1228 and 1229 milliseconds. When the energy is split, 1228 milliseconds and 1229 milliseconds account for 0.8 and 0.2 respectively.

[0076] Attached Figure 3The flowchart is a specific embodiment of the non-stretching distortion dynamic correction method of the split moving of the present invention. Compared with the conventional dynamic correction method, it has three differences: first, the calculation steps of the conventional dynamic correction method are reversed, and the position after dynamic correction is calculated from the position before dynamic correction; second, the dynamic correction amount of the corresponding co-directional axis is calculated according to the time-distance curve using the TV speed pair, and then interpolated, while the conventional dynamic correction is to interpolate the speed first and then calculate the static correction amount; third, the conventional combined moving is changed to split moving.

[0077] Embodiment three:

[0078] As attached Figure 1 In step 1, input the pre-stack seismic data and time-velocity pairs to be corrected. Figure 2 The pre-stack seismic data to be corrected contains four phase axes. The corresponding input four time-velocity pairs are (325, 1980), (703, 2030), (1042, 2410), (1384, 2730). The first one represents the time sampling point, which is multiplied by the time sampling interval to get the time, and the second one is the velocity.

[0079] In step 2, the wavelength corresponding to each time-velocity pair is calculated.

[0080] In step three, the event axis center trajectory and dynamic correction corresponding to each time-velocity pair are calculated.

[0081] In step 4, the dynamic correction value is assigned, according to the wavelength calculated in step 2, the center trajectory of the event axis calculated in step 3 and the dynamic correction value, and the dynamic correction value of the event axis is assigned to the area above and below the center of the event axis trajectory. For the sampling points above the first event axis, the dynamic correction value is assigned to the dynamic correction value of the first event axis, and for the sampling points below the last event axis, the dynamic correction value is assigned to the dynamic correction value of the last event axis.

[0082] Step 5: Get the dynamic correction of the remaining sampling points by interpolation. Figure 5 and attached Figure 6 is the dynamic correction amount. It can be seen that the dynamic correction amount of the shallow layer is larger, and that of the deep layer is smaller. Figure 5 is the normal movement correction amount of the conventional normal movement correction method before normal movement correction. Since the conventional method calculates the amplitude before normal movement correction based on the position after normal movement correction, the position of the shallow far channel (corresponding to the adjacent Figure 5 The upper right corner) is blank; the present invention first calculates the dynamic correction amount before dynamic correction, and then moves the data before dynamic correction to the track gather after dynamic correction, so as shown in the attached Figure 6 As shown, the entire dynamic correction amount has data, but the position of the shallow distant track (corresponding to the adjacent Figure 6When the dynamic correction amount is set to the upper right corner, the dynamic correction at that position is automatically canceled because the time after correction is a negative value.

[0083] In step six, the dynamic correction is split. According to the dynamic correction amount calculated in step five, for each sampling point before the dynamic correction, its time minus the dynamic correction amount is the time after the dynamic correction. Since the time after the dynamic correction is usually not an integer multiple of the time sampling interval, it is necessary to split the amplitude of the sampling point into two adjacent integer sampling time intervals after the dynamic correction. In the splitting process, the energy of the sampling point is split according to the distance between the time after the dynamic correction and the positions of the two adjacent integer sampling time intervals. The farther the distance, the smaller the proportion. For example, if the time sampling interval is 1 millisecond and the time after the dynamic correction is 1228.2 milliseconds, the two adjacent integer sampling time intervals are 1228 and 1229 milliseconds. When the energy is split, 1228 milliseconds and 1229 milliseconds account for 0.8 and 0.2 respectively.

[0084] Step 7 Output the correction result without stretching distortion, attached Figure 7 is the result of conventional dynamic correction. Figure 4 Compared with the model data before dynamic correction, it can be seen that the phase axis has stretching distortion at far offset. Figure 8 This is the dynamic correction result of the present invention. Since each sampling point of the in-phase axis waveform has the same dynamic correction amount, and the splitting and moving process will not cause the same sampling point to be moved by multiple waves, it can effectively avoid dynamic correction stretching distortion. Fig. 9 This is the amplitude spectrum of the conventional dynamic correction result. It can be seen that with the increase of the offset, the frequency tends to move toward low frequency, which is caused by stretching distortion. Fig.10 This is the amplitude spectrum of the dynamic correction result of the present invention. It can be seen that there is no trend of frequency moving toward low frequency, which shows that the present invention can effectively realize dynamic correction without stretching distortion.

[0085] In order to illustrate the processing effect of the present invention on actual data, the attached Fig.11 Perform dynamic correction on the CRP gathers shown in the figure and analyze the dynamic correction effect. Fig.12 and attached Fig.13 is the dynamic correction amount. It can be seen that the dynamic correction amount of the shallow layer is larger, and that of the deep layer is smaller. Fig.12 is the normal movement correction amount of the conventional normal movement correction method before normal movement correction. Since the conventional method calculates the amplitude before normal movement correction based on the position after normal movement correction, the position of the shallow far channel (corresponding to the adjacent Fig.12 The upper right corner) is blank; the present invention first calculates the dynamic correction amount before dynamic correction, and then moves the data before dynamic correction to the track gather after dynamic correction, so as shown in the attached Fig.13 As shown in the figure, the whole dynamic correction amount has data, but when the dynamic correction amount of the shallow and distant position is used, the dynamic correction of this position is automatically cancelled because the time after correction is a negative value. Fig.14 This is the result of conventional dynamic correction. It can be seen that there is stretching distortion at the far offset positions of 1 second, 1.2 seconds, and 1.4 seconds, and the smaller the time, the more serious the stretching distortion. Fig.15 This is the result of the non-stretching dynamic correction of the split-and-moved method of the present invention. It can be seen that the waveform of the strong event axis is not stretched. Fig.16 is the amplitude spectrum of the conventional dynamic correction result. It can be seen that as the offset increases, the energy of the high frequency gradually decreases, that is, it moves toward the low frequency direction. Fig.17 This is the amplitude spectrum of the dynamic correction result of the present invention. It can be seen that the trend of the frequency moving toward the low frequency direction is suppressed, indicating that the present invention can effectively avoid the stretching distortion of the conventional dynamic correction.

[0086] The present invention enables each sampling point of an event axis in each seismic trace to have the same dynamic correction amount, and the moving process is to split the sampling points before dynamic correction into the data after dynamic correction, ensuring that the amplitude of a sampling point is moved only once, thereby effectively avoiding stretching distortion. The present invention makes full use of the number of effective traces in shallow and middle layer stacking, and improves the imaging quality of shallow and middle layers after stacking.

[0087] In the absence of conflicts, technicians in this field can combine the relevant technical features in the above examples according to actual conditions to achieve corresponding technical effects. The specific combinations are not described here one by one.

[0088] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0089] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0090] The above are only preferred embodiments of the present invention. The present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein. Any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for correcting distortion without stretching during splitting and moving, characterized by: The steps include: Step 1, input pre-stack seismic data and time-velocity pairs to be corrected; Step 2: Calculate the wavelength corresponding to each time-velocity pair; Step 3, calculating the event axis center trajectory and dynamic correction amount corresponding to each time-velocity pair; Step 4: Assign the dynamic correction value within the half-wavelength range on both sides of the center of the event axis; Step 5, obtaining the dynamic correction values ​​of the sampling points in the remaining areas; Step 6: Disassemble and move the equipment for correction; Step 7: Output the correction result without stretching distortion.

2. A method for correcting the non-stretching distortion of splitting and moving as claimed in claim 1, characterized in that: The method of time-speed pair in step 1 is to multiply the time sampling point by the time sampling interval to obtain the time, and the time and the corresponding speed together form a time-speed pair.

3. The method for correcting the non-stretching distortion of splitting and moving as claimed in claim 1, characterized in that: The method for calculating the wavelength corresponding to each time-speed pair in step 2 is as follows: The first step is to use the time-velocity pair to calculate the trajectory of the event axis and intercept the data within a period of time above and below the trajectory; Step 2: Calculate the amplitude spectrum of the data in step 1; The third step is to smooth the amplitude spectrum; Step 4: Calculate the wavelength using the formula λ=vf; Where: λ is the wavelength, meters; v is the velocity of the time-velocity pair, m / s; f is the main frequency, Hz.

4. A method for correcting the non-stretching distortion of splitting and moving as claimed in claim 3, characterized in that: The third step of smoothing the amplitude spectrum is to set a proportional coefficient, and determine an amplitude value by multiplying the proportional coefficient and the maximum amplitude value. The amplitude value corresponds to at least two points on the amplitude spectrum, and the average of the frequencies corresponding to these points is taken as the main frequency.

5. The method for correcting the non-stretching distortion of splitting and moving as claimed in claim 1, characterized in that: The method for calculating the dynamic correction amount of the position corresponding to the time-velocity pair in step 2 is to calculate the corresponding event axis center trajectory and dynamic correction amount based on the time-velocity pair, and assign the same dynamic correction amount to the range of the upper and lower half wavelengths centered on the trajectory of the event axis center position.

6. The method for correcting the non-stretching distortion of splitting and moving equipment according to claim 1, characterized in that: The method for assigning the dynamic correction amount in step 4 is: according to the wavelength calculated in step 2, using the event axis center trajectory and the dynamic correction amount calculated in step 3, assigning the dynamic correction amount of the event axis in the area above and below the center of the event axis trajectory; for the sampling points above the first event axis, the dynamic correction amount is assigned to the dynamic correction amount of the first event axis, and for the sampling points below the last event axis, the dynamic correction amount is assigned to the dynamic correction amount of the last event axis.

7. The method for correcting the non-stretching distortion of splitting and moving equipment according to claim 1, characterized in that: The method for obtaining the dynamic correction values ​​of the sampling points in the remaining areas in step 5 is to obtain the dynamic correction values ​​of the remaining sampling points by interpolation.

8. The method for correcting the non-stretching distortion of splitting and moving equipment as claimed in claim 1, characterized in that: The method for splitting the moving correction in step six is ​​based on the moving correction amount obtained in step five. For each sampling point before the moving correction, its time minus the moving correction amount is the time after the moving correction. If the time after the moving correction is not an integer multiple of the time sampling interval, the amplitude of the sampling point is split into two positions of two adjacent integer sampling time intervals after the moving correction. In the process of splitting, the energy of the sampling point is split according to the distance between the time after the moving correction and the positions of two adjacent integer sampling time intervals, and the farther the distance, the smaller the proportion.

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