Method, apparatus and device for resolving phase differences between channels of microtremor acquisition equipment

Abstract

The application relates to a micro-motion acquisition device inter-channel phase difference constraint unwrapping method, device and equipment in the micro-motion exploration technical field, which comprises the following steps: preprocessing two-channel synchronous acquisition micro-motion original time sequences, calculating mutual power spectrum and extracting folded phase; performing preliminary unwrapping on the original folded phase, correcting the polarity of the original folded phase sequence according to the preliminary unwrapping phase sequence; constructing a reference slope constraint interval, performing interval translation according to the systematic phase offset of a target acquisition device, performing global constraint unwrapping by adopting a reference line period matching method according to the unwrapping constraint interval, performing oblique period homing correction on the constraint unwrapping phase sequence, and obtaining real inter-channel phase difference data. The three-level processing mechanism of preliminary unwrapping polarity judgment + global slope constraint + period linkage homing solves the problems of unreliable polarity judgment, easy period jumping, difficult correction of device systematic deviation and poor engineering adaptability of existing unwrapping algorithms.

Description

Technical Field

[0001] This invention belongs to the field of micro-motion exploration technology, and relates to a method, apparatus and equipment for constraining and untangling the phase difference between channels in a micro-motion acquisition device. Background Technology

[0002] Micro-motion exploration is one of the core technologies of natural source surface wave exploration. It extracts Rayleigh surface wave dispersion curves by collecting weak natural vibration signals from the Earth's surface and inverts the S-wave velocity structure of shallow strata. It has advantages such as not requiring artificial seismic sources, high detection efficiency, and environmental friendliness, and is widely used in engineering geological exploration, urban underground space exploration, geological disaster monitoring and other fields.

[0003] Accurate unwrapping of the phase difference between channels is a core prerequisite for dispersion curve extraction. The conventional processing procedure is as follows: cross-power spectrum estimation is performed on the micro-motion time series acquired simultaneously from two channels to obtain the original phase sequence folded within the interval; the continuous true phase difference is recovered through the phase unwrapping algorithm; the surface wave phase velocity is calculated based on the slope of the phase difference change with frequency, and finally the dispersion curve is generated, which is then imported into professional processing software to complete the stratigraphic inversion.

[0004] Currently, the mainstream phase unwrapping technique is represented by point-by-point recursive unwrapping. This algorithm compares the phase difference between adjacent frequency points point by point, and adds or subtracts to the next frequency point when the difference exceeds the threshold to achieve phase continuity. Its core relies on the premise that "the actual phase difference between adjacent frequency points is less than the threshold". It is logically simple and has a fast calculation speed, but it has significant limitations in practical engineering applications: field-acquired data generally suffers from environmental noise interference, insufficient signal-to-noise ratio in the low-frequency band, and random phase jumps in the local area. These problems can easily lead to integer-cycle jumps during the unwrapping process, resulting in a sawtooth-shaped distortion in the unwrapped phase curve. The phase slope obtained by fitting the final phase curve deviates significantly from the true value, directly causing the dispersion curve calculation to fail.

[0005] To improve unwrapping stability, some schemes introduce fixed velocity range constraints, calculating the upper and lower limits of the phase slope based on the prior velocity range of the work area, and performing range verification on the unwrapping results. However, this scheme only sets a fixed constraint interval and does not consider the systematic integer-cycle phase shift and polarity reversal problem of the acquisition equipment itself. Different models and batches of micro-motion acquisition equipment are affected by factors such as hardware circuit design, sensor wiring polarity, and filter phase response, resulting in a generally systematic phase shift between channels, with some equipment having shifts on the order of an integer cycle. On the one hand, the overall trend polarity cannot be accurately determined in the folded phase state, which easily leads to misalignment of the constraint interval direction; on the other hand, when the equipment phase shift causes the true slope to fall outside the fixed constraint interval, the unwrapping result will be forcibly corrected to the wrong cycle, which will exacerbate the slope estimation error. Finally, the extracted dispersion curve deviates from the true geological velocity range of the work area and cannot be correctly returned to its original position.

[0006] Other complex two-dimensional unwrapping algorithms, such as quality map-guided unwrapping and minimum norm unwrapping, are mostly used in fields such as InSAR and optical interferometry. Although they have high unwrapping accuracy, their computational logic is complex and the processing time is long. For one-dimensional phase sequences in micro-motion exploration, they consume excessive computing power and are difficult to adjust parameters, making them unsuitable for the automated and engineering processing needs of large-scale exploration data. Summary of the Invention

[0007] To address the problem that existing micro-motion phase unwrapping techniques cannot simultaneously ensure reliability of polarity discrimination, unwrapping stability, repositioning accuracy, and processing efficiency, this invention proposes a constrained unwrapping method, apparatus, and device for inter-channel phase difference in micro-motion acquisition equipment. This method is adaptable to micro-motion exploration scenarios and can automatically correct polarity, suppress cycle skipping errors, correct systematic phase shifts in the equipment, and ensure correct repositioning of dispersion curves.

[0008] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: On the one hand, a constraint unwrapping method for inter-channel phase difference in a micro-motion acquisition device is provided, including the following steps: Step 1: Preprocess the two synchronously acquired micro-motion raw time series, calculate the cross power spectrum based on the preprocessing results, and extract the folded phase based on the cross power spectrum to obtain the raw folded phase sequence.

[0009] Step 2: Use the classic point-by-point recursive algorithm to perform preliminary unwrapping on the original folded phases to obtain a preliminary unwrapped phase sequence. Then, perform polarity correction on the original folded phase sequence based on the preliminary unwrapped phase sequence.

[0010] Step 3: Construct a benchmark slope constraint interval based on the prior geological knowledge of the work area, and perform interval translation according to the systematic phase offset of the target acquisition equipment to generate an unwrapped constraint interval adapted to the target equipment.

[0011] Step 4: Based on the unwrapping constraint interval, use the reference line period matching method to perform global constraint unwrapping, and output a continuous constraint unwrapping phase sequence with compliant slope.

[0012] Step 5: Perform oblique periodic repositioning correction on the constrained unwrapped phase sequence to obtain the true inter-track phase difference data.

[0013] On the other hand, a constraint untangling device for inter-channel phase difference of a micro-motion acquisition device is also provided, including: a data input unit, a core processing unit, a human-machine interaction unit and a data storage unit.

[0014] The data input unit is used to import the original micro-motion time series acquired simultaneously from two channels and transmit the original micro-motion time series to the core processing unit.

[0015] The core processing unit includes: a cross-spectral phase extraction and polarity correction module, a constraint interval adaptation module, a global constraint unwrapping module, and a return output module. These modules sequentially complete steps 1 to 5 of the constraint unwrapping method for inter-channel phase difference of the micro-motion acquisition device, and output the final true inter-channel phase difference data.

[0016] The human-computer interaction unit is used to configure track spacing, analyze frequency band range, period repositioning amount, and upper and lower limits of constraint intervals. It displays the original folded phase, unwrapped phase curve, and fitting slope in real time, and supports operators to adjust parameters and recalculate.

[0017] Data storage unit: Used to store original phase data, unwrapping intermediate results, slope parameters, and final phase difference curves, and supports data export in industry standard formats.

[0018] In another aspect, a computer device is also provided, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps of the constraint untangling method for inter-channel phase difference of the micro-motion acquisition device described above.

[0019] One of the above technical solutions has the following advantages and beneficial effects: The aforementioned method, apparatus, and equipment for constrained unwrapping of inter-channel phase difference in micro-motion acquisition equipment include: preprocessing the original micro-motion time series acquired from two synchronous acquisitions; calculating the cross-power spectrum based on the preprocessing results; extracting folded phases based on the cross-power spectrum to obtain an original folded phase sequence; performing preliminary unwrapping of the original folded phases using a classical point-by-point recursive algorithm to obtain a preliminary unwrapped phase sequence; performing polarity correction on the original folded phase sequence based on the preliminary unwrapped phase sequence; constructing a benchmark slope constraint interval based on prior geological knowledge of the work area; performing interval translation based on the systematic phase offset of the target acquisition equipment to generate an unwrapped constraint interval adapted to the target equipment; performing global constraint unwrapping using a reference line period matching method based on the unwrapped constraint interval to output a continuous and slope-compliant constrained unwrapped phase sequence; and performing oblique periodic realignment correction on the constrained unwrapped phase sequence to obtain the true inter-channel phase difference data. This method addresses the problems of unreliable polarity determination, easy period skipping, difficulty in correcting systematic equipment offsets, inability to correctly reposition dispersion curves, and poor engineering adaptability of existing unwrapping algorithms through a three-level processing mechanism of "preliminary unwrapping polarity determination + global slope constraint + periodic linkage repositioning". While ensuring the stability of phase unwrapping and the accuracy of slope estimation, it outputs standard phase results that can be directly imported into the Geogiga Seismic Pro processing software, is compatible with existing engineering processing workflows, and is adapted for automated batch data processing. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating a method for constrained untangling of interchannel phase difference in a micro-motion acquisition device in one embodiment. Figure 2 This is a comparison diagram of the phase unwrapping results of the first, second, and fifth pairs in one embodiment. Figure 2 (a)~ Figure 2 (c) in the diagram represents the original folded phase of the first pair, the traditional point-by-point unwrapping result, and the constrained unwrapping result of this method, respectively. Figure 2 (d)~ Figure 2 In the diagram, (f) represents the original folded phase of the second pair, the traditional point-by-point unwrapping result, and the constrained unwrapping result of this method, respectively. Figure 2 (g)~ Figure 2 In the diagram, (i) represents the original folded phase of the 5th pair, the traditional point-by-point unwrapping result, and the constrained unwrapping result of this method, respectively. Figure 3 This is a comparison chart of dispersion curves before and after constraint unwrapping in the first embodiment, where... Figure 3 (a) in the figure is a schematic diagram of the dispersion curve before constraint unwrapping. Figure 3 (b) in the diagram is a schematic diagram of the dispersion curve after constraint unwrapping; Figure 4 This is a comparison chart of the dispersion curves before and after constraint unwrapping in the fifth pass of one embodiment, where... Figure 4 (a) in the figure is a schematic diagram of the dispersion curve before constraint unwrapping. Figure 4 (b) in the figure is a schematic diagram of the dispersion curve after constraint unwrapping. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0024] It should be noted that, in this document, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The presentation of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments. The term "and / or" as used herein refers to any combination of one or more of the associated listed items, and all possible combinations, including such combinations.

[0025] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0026] In one embodiment, such as Figure 1 As shown, a constraint unwrapping method for inter-channel phase difference in a micro-motion acquisition device is provided, which may include the following processing steps 1 to 5: Step 1: Preprocess the two synchronously acquired micro-motion raw time series, calculate the cross power spectrum based on the preprocessing results, and extract the folded phase based on the cross power spectrum to obtain the raw folded phase sequence.

[0027] Specifically, the two synchronously acquired micro-motion raw time series... , After preprocessing, the cross power spectrum is calculated and the folded phase is extracted as the basic input for subsequent processing.

[0028] Step 2: Use the classic point-by-point recursive algorithm to perform preliminary unwrapping on the original folded phases to obtain a preliminary unwrapped phase sequence. Then, perform polarity correction on the original folded phase sequence based on the preliminary unwrapped phase sequence.

[0029] Specifically, the process first obtains a continuous preliminary untangling result through traditional point-by-point recursion, then determines the overall trend polarity based on the continuous phase, and finally unifies the polarity of the original folded phase to eliminate the sign error caused by the reversal of the polarity of the equipment wiring and the inversion of the polarity of the sensor.

[0030] Step 3: Construct a benchmark slope constraint interval based on the prior geological knowledge of the work area, and perform interval translation according to the systematic phase offset of the target acquisition equipment to generate an unwrapped constraint interval adapted to the target equipment.

[0031] Specifically, a global slope-constrained unwrapping mechanism is adopted, upgrading the unwrapping basis from the traditional "local phase difference between adjacent frequency points" to a "global geological slope constraint interval." This uses prior geological knowledge of the work area to macroscopically lock in a reasonable range for the phase period, completely breaking the error propagation chain of point-by-point recursion. Local phase noise will not cause global period jump errors. Combined with the dual guarantee of reference line period matching and slope closed-loop verification, the unwrapping success rate in low signal-to-noise ratio scenarios is significantly improved, and the output phase curve is continuous and smooth, without jagged jump distortion.

[0032] Step 4: Based on the unwrapping constraint interval, use the reference line period matching method to perform global constraint unwrapping, and output a continuous constraint unwrapping phase sequence with compliant slope.

[0033] Specifically, based on the translated unwrapping constraint interval, the reference line period matching method is used for global constraint unwrapping, replacing the traditional point-by-point recursive logic, and outputting a continuous constraint unwrapping phase sequence with compliant slope.

[0034] Step 5: Perform oblique periodic repositioning correction on the constrained unwrapped phase sequence to obtain the true inter-track phase difference data.

[0035] Specifically, the constraint unwrapping phase is corrected to eliminate the influence of systematic phase shift in the equipment, restore the true inter-channel phase difference, and output phase data that meets industry standards. This data can be directly imported into the Geogiga Seismic Pro processing software to extract dispersion curves.

[0036] The "constrained interval translation + oblique periodic realignment" linkage correction mechanism: Before unwrapping, the interval translation adapts to the systematic phase shift of the equipment, ensuring that the unwrapping process always proceeds within the correct period; after unwrapping, oblique realignment accurately offsets the slope increment caused by the periodic shift, restoring the phase slope to the baseline geological velocity range. This mechanism can effectively eliminate hardware phase differences between different acquisition devices, and the final output phase slope closely matches the actual geological conditions; the dispersion curve extracted by Geogiga Seismic Pro processing software can be accurately realigned to a reasonable velocity range, significantly improving the reliability of geological interpretation, and the output results are fully compatible with existing engineering processing workflows.

[0037] This method primarily utilizes one-dimensional linear computation throughout the entire process, eliminating complex iterations and multi-path traversal. It achieves extremely short processing times per channel and low computational requirements. Core parameters (cycle repositioning, constraint intervals, analysis frequency bands, etc.) all support custom configuration. Adjusting the cycle repositioning allows for rapid adaptation to micro-motion acquisition devices with different phase characteristics, without requiring modification to the core algorithm logic. The overall solution can be directly packaged as a software module and embedded into existing micro-motion data processing workflows, supporting automated batch processing of large volumes of exploration data. It boasts low engineering implementation costs and high application value.

[0038] The aforementioned constrained unwrapping method for inter-channel phase difference of the micro-motion acquisition device includes: preprocessing the original micro-motion time series acquired from two synchronous acquisitions; calculating the cross-power spectrum based on the preprocessing results; extracting the folded phase based on the cross-power spectrum to obtain the original folded phase sequence; performing preliminary unwrapping of the original folded phase using a classical point-by-point recursive algorithm to obtain a preliminary unwrapped phase sequence; performing polarity correction on the original folded phase sequence based on the preliminary unwrapped phase sequence; constructing a benchmark slope constraint interval based on prior geological knowledge of the work area; performing interval translation based on the systematic phase offset of the target acquisition device to generate an unwrapped constraint interval adapted to the target device; performing global constraint unwrapping using a reference line period matching method based on the unwrapped constraint interval to output a continuous and slope-compliant constrained unwrapped phase sequence; and performing oblique periodic realignment correction on the constrained unwrapped phase sequence to obtain the true inter-channel phase difference data. This method addresses the problems of unreliable polarity determination, easy period skipping, difficulty in correcting systematic equipment offsets, inability to correctly reposition dispersion curves, and poor engineering adaptability of existing unwrapping algorithms through a three-level processing mechanism of "preliminary unwrapping polarity determination + global slope constraint + periodic linkage repositioning". While ensuring the stability of phase unwrapping and the accuracy of slope estimation, it outputs standard phase results that can be directly imported into the Geogiga Seismic Pro processing software, is compatible with existing engineering processing workflows, and is adapted for automated batch data processing.

[0039] In one embodiment, step 1 includes: performing mean removal, linear trend removal, and segmented windowing processing on the two synchronously acquired micro-motion raw time series to obtain a first processing result and a second processing result; performing Fast Fourier Transform on the i-th segment of the time-domain data of the first processing result and the second processing result to obtain a first frequency domain sequence and a second frequency domain sequence; calculating the cross-power spectrum of the first frequency domain sequence and the second frequency domain sequence in each segment; averaging the cross-power spectra of all segments to obtain a smoothed cross-power spectrum; and extracting the argument of the smoothed cross-power spectrum to obtain the folded cross-power spectrum. The original folded phase sequence within the interval.

[0040] Specifically, the process of cross-power spectrum calculation and folded phase extraction includes: (1) Data preprocessing: This involves removing the mean, removing linear trends, and segmenting the data into windows. Let the length of a single data segment be... The segment overlap rate is The Hanning window was used to apply windowing to each segment of data; for the first segment... Time-domain data , Perform a Fast Fourier Transform to obtain the corresponding frequency domain sequence. , .

[0041] (2) Cross-power spectrum estimation: Average the cross-power spectrum of all segments to obtain the smoothed cross-power spectrum. for: ; in, The total number of valid segments, for .

[0042] (3) Folded Phase Extraction: Take the argument of the cross-power spectrum to obtain the folded phase. Original folded phase sequence within the interval , .

[0043] In one embodiment, step 2 includes: performing preliminary unwrapping of the original folded phase using a classical point-by-point recursive algorithm to obtain a continuous but potentially locally skipped period error preliminary unwrapped phase sequence; selecting frequency segments at the beginning and end of the preliminary unwrapped phase sequence, each accounting for a predetermined percentage of the total length, and calculating the phase mean within the selected first and last frequency segments to obtain the first phase mean and the last phase mean; if the last phase mean is less than the first phase mean, it is determined to be a negative slope polarity, and the original folded phase is reversed as a whole; otherwise, the original folded phase remains unchanged.

[0044] Specifically, the preliminary untangling and automatic polarity correction process includes: (1) Preliminary point-by-point unwrapping: The original folded phase is initially unwrapped using the classical point-by-point recursive algorithm to obtain a continuous but potentially localized periodic jump error preliminary unwrapped phase. .

[0045] (2) Overall polarity determination: Take frequency segments that account for 10% of the total length at the beginning and end of the preliminary unwrapped phase sequence, and calculate the average phase value within each segment: ; in, To effectively analyze the initial frequency, To effectively analyze the termination frequency, To analyze the frequency band bandwidth.

[0046] (3) Polarity correction output: If If the slope polarity is negative, the original folded phase is reversed; otherwise, the original folded phase remains unchanged. ; Folded phase after output polarity correction Then proceed to the subsequent constraint untangling process.

[0047] In one embodiment, step 3 includes: constructing a benchmark slope constraint interval based on prior geological knowledge of the work area; pre-calibrating the periodic repositioning amount according to the systematic phase offset characteristics of the target acquisition equipment; and based on the periodic repositioning amount and... The phase shift over an entire cycle is used to determine the bandwidth of the analysis frequency band. The corresponding slope increment is ;in The periodic repositioning amount is used; the baseline constraint interval is shifted as a whole based on the slope increment to generate an untangling constraint interval adapted to the target device.

[0048] In one embodiment, constructing a benchmark slope constraint interval based on prior geological knowledge of the work area includes: determining the slope of the inter-track phase difference as a function of frequency according to the principle of surface wave propagation: ; in, The slope of the inter-channel phase difference as a function of frequency. There are two spacing lines. For surface wave phase velocity, Inter-channel phase difference, For frequency.

[0049] Combined with the reasonable surface wave phase velocity range of the work area The slope of the change is converted to obtain the reference slope constraint interval of the phase difference slope; the reference slope constraint interval serves as the geological benchmark for unwrapping verification and periodic repositioning.

[0050] Specifically, slope constraint interval construction and device adaptation translation: (1) Construction of the reference slope constraint interval: According to the principle of surface wave propagation, the distance between the two channels is The phase velocity of the surface wave is At that time, the slope of the inter-channel phase difference as a function of frequency is: slope With phase velocity One-to-one correspondence, unit is Combined with the reasonable surface wave velocity range of the work area The benchmark constraint range for the phase difference slope is obtained by conversion. This interval corresponds to the reasonable range of the true phase slope under the geological conditions of the work area, and serves as the geological benchmark for unwrapping verification and periodic repositioning.

[0051] (2) Synchronous translation of the untangled constraint interval: Based on the systematic phase offset characteristics of the target acquisition equipment, the periodic repositioning amount is pre-calibrated. (Unit: individuals) The cycle can be calibrated by benchmarking against a high-precision reference device.

[0052] The phase shift of a whole cycle is in The corresponding slope increment within the bandwidth is The baseline constraint interval is shifted as a whole to generate an unwrapping constraint interval adapted to the equipment, ensuring that the unwrapping process is locked within the correct period after the equipment offset. For high-precision acquisition equipment without systematic whole-cycle phase shift, The untangling constraint interval is consistent with the benchmark constraint interval.

[0053] In one embodiment, step 4 includes: using the median of the unwrapping constraint interval as a reference slope, and taking the folding phase corresponding to the initial frequency as the starting point, generating an ideal reference phase that linearly varies with frequency as follows: ; in, For an ideal reference phase line, The starting frequency, For reference slope, Starting frequency The corresponding folded phase, For frequency; For each frequency point, calculate the difference between the folded phase and the reference phase, and match the nearest... Period, to obtain the initial untangling phase ;in, The period compensation number corresponds to the frequency point; for the initial unwrapped phase Perform a first-order linear fit to obtain the actual slope. ;like Then subtract the entire phase sequence as a whole. ;in The maximum value of the untangling constraint interval; if Then add to the entire phase sequence as a whole. Repeat the fitting and verification process until the slope falls within the unwrapping constraint range, and output the final constrained unwrapping phase sequence.

[0054] Specifically, the process of untangling the phase of the global reference line constraint includes: (1) Generate ideal reference phase line: take the median of the unwrapping constraint interval as the reference slope. : , at the starting frequency Corresponding folded phase Starting from this point, an ideal reference phase line that varies linearly with frequency is generated: .

[0055] (2) Point-by-point periodic matching and unwrapping: For each frequency point, calculate the difference between the folded phase and the reference phase, and match the nearest folded phase. Period, to obtain the initial untangling phase ; in, This represents the number of period compensations for the corresponding frequency point.

[0056] (3) Slope closed-loop verification: for the initial unwrapped phase Perform a first-order linear fit to obtain the actual slope. .like Then subtract the entire phase sequence as a whole. ;like Then add to the entire phase sequence as a whole. Repeat the fitting and verification process until the slope falls within the unwrapping constraint range, and output the final constrained unwrapping phase sequence.

[0057] In one embodiment, step 5 includes: performing an oblique linear translation on the constrained unwrapped phase sequence to pull the phase slope back to the reference geological velocity range, resulting in the repositioned phase as follows: ; in, The phase after repositioning. This is the initial untangling phase. For periodic repositioning quantity, The starting frequency, To analyze the frequency band bandwidth, For frequency.

[0058] A linear fit is performed on the repositioned phase to obtain the intercept. The intercept is subtracted from the whole to make the phase curve pass through the zero frequency point, eliminating the systematic intercept offset, and the final true inter-channel phase difference curve is obtained. The true inter-channel phase difference curve conforms to the SEG-2 and SAC industry standard data formats and is used for subsequent surface wave dispersion curve extraction, dispersion fitting and formation velocity inversion.

[0059] Specifically, the process of periodic repositioning correction and standard data output includes: (1) Oblique periodic repositioning: The constrained unwrapped phase is obliquely linearly shifted to offset the slope increment caused by the periodic offset, and the phase slope is pulled back to the reference geological velocity range:

[0060] (2) Zeroing the intercept: Perform linear fitting on the repositioned phase to obtain the intercept. Subtracting the intercept from the whole curve makes the phase curve pass through the zero frequency point, eliminating the systematic intercept offset, and obtaining the final true inter-channel phase difference curve:

[0061] (3) Standard data output: The output true inter-channel phase difference curves conform to industry standard data formats such as SEG-2 and SAC, and can be directly imported into Geogiga Seismic Pro processing software. The software can then complete the subsequent surface wave dispersion curve extraction, dispersion fitting, and formation velocity inversion. Since this method has ensured the accuracy of the phase slope, the dispersion curves extracted by Geogiga Seismic Pro processing software can be correctly assigned to the reasonable geological velocity range of the work area.

[0062] In a specific embodiment, the phase unwrapping results of the first, second, and fifth pairs are as follows: Figure 2 As shown, where Figure 2 (a) to Figure 2 (c) in the diagram represents the original folded phase of the first pair, the traditional point-by-point unwrapping result, and the constrained unwrapping result of this method, respectively. Figure 2 (d) to Figure 2 In the diagram, (f) represents the original folded phase of the second pair, the traditional point-by-point unwrapping result, and the constrained unwrapping result of this method, respectively. Figure 2 (g) to Figure 2 In the diagram, (i) represents the original folded phase of the 5th pair, the traditional point-by-point unwrapping result, and the constrained unwrapping result of this method, respectively. Figure 2 Each pair of traces sequentially displays the original folded phase, the traditional point-by-point unwrapping result, and the constrained unwrapping result of this method. Among them, the traditional unwrapping of the first and fifth trace pairs shows obvious period skipping distortion, which can be effectively corrected by this method; the data quality of the second trace pair is good, and the results of the traditional unwrapping and this method are consistent, verifying that this method does not introduce additional bias when the data quality is good, and has good universality.

[0063] The first comparison of dispersion curves before and after constraint unwrapping is shown in the figure below. Figure 3 As shown, where Figure 3 (a) in the figure is a schematic diagram of the dispersion curve before constraint unwrapping. Figure 3 (b) in the diagram is a schematic diagram of the dispersion curve after constraint unwrapping; Figure 3 The results visually demonstrate the improvement in the dispersion curve from discrete chaos to continuous alignment after periodic distortion correction.

[0064] The fifth diagram compares the dispersion curves before and after constraint unwrapping, as shown below. Figure 4 As shown, where Figure 4 (a) in the figure is a schematic diagram of the dispersion curve before constraint unwrapping. Figure 4 (b) in the figure is a schematic diagram of the dispersion curve after constraint unwrapping. For samples with more severe unwrapping distortion, the corrective ability of this method to correctly reposition the dispersion curve is verified.

[0065] It should be understood that, although Figure 1The steps are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order in which these steps are executed; they can be performed in other orders. Figure 1 At least some of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0066] In one embodiment, a constraint untangling device for inter-channel phase difference of a micro-motion acquisition device is also provided, comprising: a data input unit, a core processing unit, a human-machine interaction unit, and a data storage unit.

[0067] The data input unit is used to import the original micro-motion time series acquired simultaneously from two channels and transmit the original micro-motion time series to the core processing unit.

[0068] Specifically, the data input unit is used to import the original time series of micromotions acquired simultaneously from two channels, supporting input of mainstream seismic data formats such as SEG-2, SAC, and MiniSEED, and transmitting the original data to the core processing unit.

[0069] The core processing unit includes: a cross-spectral phase extraction and polarity correction module, a constraint interval adaptation module, a global constraint unwrapping module, and a return output module. These modules sequentially complete steps 1 to 5 of the constraint unwrapping method for inter-channel phase difference of the micro-motion acquisition device, and output the final true inter-channel phase difference data.

[0070] Specifically, the core processing unit is the computing core of the device, which has built-in cross-spectral phase extraction module, polarity correction module, constraint interval adaptation module, global constraint unwrapping module, and return output module. It sequentially completes the above-mentioned steps 1 to 5 computing processes and outputs the final real inter-channel phase difference data.

[0071] The human-computer interaction unit is used to configure track spacing, analyze frequency band range, period repositioning amount, and upper and lower limits of constraint intervals. It displays the original folded phase, unwrapped phase curve, and fitting slope in real time, and supports operators to adjust parameters and recalculate.

[0072] Data storage unit: used to store original phase data, unwrapping intermediate results, slope parameters, and final phase difference curves, and supports data export in industry standard formats.

[0073] In one embodiment, the cross-spectral phase extraction and polarity correction module is further configured to sequentially perform mean removal, linear trend removal, and segmented windowing processing on the two synchronously acquired micro-motion raw time series to obtain a first processing result and a second processing result; perform Fast Fourier Transform on the i-th segment of time-domain data of the first and second processing results to obtain a first frequency domain sequence and a second frequency domain sequence; calculate the cross-power spectrum of the first and second frequency domain sequences in each segment; average the cross-power spectra of all segments to obtain a smoothed cross-power spectrum; and extract the argument of the smoothed cross-power spectrum to obtain the folded cross-power spectrum. The original folded phase sequence within the interval.

[0074] In one embodiment, the cross-spectral phase extraction and polarity correction module is used to perform preliminary unwrapping of the original folded phase using a classical point-by-point recursive algorithm to obtain a continuous but potentially locally skipped period error preliminary unwrapped phase sequence; select frequency segments at the beginning and end of the preliminary unwrapped phase sequence, each accounting for a preset percentage of the total length, and calculate the phase mean within the selected first and last frequency segments respectively to obtain the first phase mean and the last phase mean; if the last phase mean is less than the first phase mean, it is determined to be a negative slope polarity, and the original folded phase is reversed as a whole; otherwise, the original folded phase remains unchanged.

[0075] In one embodiment, the constraint interval adaptation module is used to construct a benchmark slope constraint interval based on prior geological knowledge of the work area; pre-calibrate the periodic repositioning amount according to the systematic phase offset characteristics of the target acquisition equipment; and based on the periodic repositioning amount and... The phase shift over an integer period, of which This refers to the periodic repositioning quantity; within the analysis frequency band bandwidth. The corresponding slope increment within the bandwidth is The baseline constraint interval is translated as a whole based on the slope increment to generate an untangling constraint interval adapted to the target device.

[0076] In one embodiment, constructing a benchmark slope constraint interval based on prior geological knowledge of the work area includes: determining the slope of the inter-track phase difference as a function of frequency according to the principle of surface wave propagation: ; in, The slope of the inter-channel phase difference as a function of frequency. There are two spacing lines. For surface wave phase velocity, Inter-channel phase difference, For frequency.

[0077] Combined with the reasonable surface wave phase velocity range of the work area The slope of the change is converted to obtain the reference slope constraint interval of the phase difference slope; the reference slope constraint interval serves as the geological benchmark for unwrapping verification and periodic repositioning.

[0078] In one embodiment, the global constraint unwrapping module is used to generate an ideal reference phase that linearly varies with frequency, using the median of the unwrapping constraint interval as a reference slope and the folded phase corresponding to the initial frequency as the starting point: ; in, For an ideal reference phase line, The starting frequency, For reference slope, Starting frequency The corresponding folded phase.

[0079] For each frequency point, calculate the difference between the folded phase and the reference phase, and match the nearest... Period, to obtain the initial untangling phase ;in, The period compensation number corresponds to the frequency point; for the initial unwrapped phase Perform a first-order linear fit to obtain the actual slope. ;like Then subtract the entire phase sequence as a whole. ;in The maximum value of the untangling constraint interval; if Then add to the entire phase sequence as a whole. Repeat the fitting and verification process until the slope falls within the unwrapping constraint range, and output the final constrained unwrapping phase sequence.

[0080] In one embodiment, the repositioning output module is used to perform an oblique linear shift on the constrained unwrapped phase sequence, pulling the phase slope back to the reference geological velocity range, resulting in the repositioned phase as follows: ; in, The phase after repositioning. This is the initial untangling phase. For periodic repositioning quantity, The starting frequency, To analyze the frequency band bandwidth.

[0081] A linear fit is performed on the repositioned phase to obtain the intercept. The intercept is subtracted from the whole to make the phase curve pass through the zero frequency point, eliminating the systematic intercept offset, and the final true inter-channel phase difference curve is obtained. The true inter-channel phase difference curve conforms to the SEG-2 and SAC industry standard data formats and is used for subsequent surface wave dispersion curve extraction, dispersion fitting and formation velocity inversion.

[0082] It is understood that for a detailed explanation of the constraint unwrapping device for the inter-channel phase difference of the micro-motion acquisition device, please refer to the corresponding explanations of the various embodiments of the constraint unwrapping method for the inter-channel phase difference of the micro-motion acquisition device above, and will not be repeated here. Each module in the aforementioned constraint unwrapping device for the inter-channel phase difference of the micro-motion acquisition device can be implemented entirely or partially through software, hardware, or a combination thereof. Each module can be embedded in hardware or independently of a device with data processing capabilities, or stored in software in the memory of the aforementioned device, so that the processor can call and execute the operations corresponding to each module. The aforementioned device can be, but is not limited to, various types of data processing computer devices already existing in the art.

[0083] In one embodiment, a computer device is also provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the embodiment of the constraint untangling method for inter-channel phase difference of the micro-motion acquisition device described above.

[0084] It is understood that, in addition to the memory and processor mentioned above, the computer equipment described above also includes other hardware and software components not listed in this specification. The specific components can be determined according to the model of the image processing computer in different application scenarios, and will not be listed and described in detail in this specification.

[0085] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0086] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and all such modifications and improvements fall within the scope of protection of this application.

Claims

1. A method for constrained untangling of inter-channel phase difference in a micro-motion acquisition device, characterized in that, Including the following steps: Step 1: Preprocess the two synchronously acquired micro-motion raw time series, calculate the cross power spectrum based on the preprocessing results, and extract the folded phase based on the cross power spectrum to obtain the raw folded phase sequence; Step 2: Use the classic point-by-point recursive algorithm to perform preliminary unwrapping on the original folded phase to obtain a preliminary unwrapped phase sequence. Then, perform polarity correction on the original folded phase sequence based on the preliminary unwrapped phase sequence. Step 3: Construct a benchmark slope constraint interval based on the prior geological knowledge of the work area, and perform interval translation according to the systematic phase offset of the target acquisition equipment to generate an unwrapped constraint interval adapted to the target equipment; Step 4: Based on the unwrapping constraint interval, perform global constraint unwrapping using the reference line period matching method, and output a continuous constraint unwrapping phase sequence with compliant slope; Step 5: Perform oblique periodic repositioning correction on the constrained unwrapped phase sequence to obtain the true inter-track phase difference data.

2. The constraint untangling method for inter-channel phase difference in a micro-motion acquisition device according to claim 1, characterized in that, Step 1 includes: The two synchronously acquired micro-motion raw time series are subjected to mean removal, linear trend removal, and segmented windowing processing respectively to obtain the first processing result and the second processing result. The i-th segment of time domain data of the first processing result and the second processing result are subjected to fast Fourier transform to obtain the first frequency domain sequence and the second frequency domain sequence respectively. Calculate the cross power spectrum of the first frequency domain sequence and the second frequency domain sequence in each segment, and average the cross power spectrum of all segments to obtain the smoothed cross power spectrum. Extracting the argument of the smoothed cross-power spectrum yields the folded... The original folded phase sequence within the interval.

3. The constraint untangling method for inter-channel phase difference in a micro-motion acquisition device according to claim 1, characterized in that, Step 2 includes: The original folded phase is initially unwrapped using the classic point-by-point recursive algorithm to obtain a continuous but potentially localized periodic skip error preliminary unwrapped phase sequence; Select frequency segments at the beginning and end of the preliminary unwrapped phase sequence, each representing a predetermined percentage of the total length. Calculate the average phase value within the selected first and last frequency segments to obtain the first and last average phase values. If the mean value of the tail phase is less than the mean value of the first phase, it is determined to be a negative slope polarity, and the original folded phase is reversed as a whole; otherwise, the original folded phase remains unchanged.

4. The constraint untangling method for inter-channel phase difference in a micro-motion acquisition device according to claim 1, characterized in that, Step 3 includes: A baseline slope constraint interval is constructed based on prior geological knowledge of the work area. Based on the systematic phase offset characteristics of the target acquisition device, the periodic repositioning amount is pre-calibrated; Based on the periodic repositioning amount and The phase shift over an entire cycle is used to determine the bandwidth of the analysis frequency band. The corresponding slope increment is ;in This refers to the periodic repositioning amount; The baseline constraint interval is translated as a whole based on the slope increment to generate an untangled constraint interval adapted to the target device.

5. The constraint untangling method for inter-channel phase difference in a micro-motion acquisition device according to claim 1, characterized in that, Based on prior geological knowledge of the work area, a benchmark slope constraint interval is constructed, including: Based on the principle of surface wave propagation, the slope of the inter-channel phase difference as a function of frequency is determined as follows: in, The slope of the inter-channel phase difference as a function of frequency. There are two spacing lines. For surface wave phase velocity, Inter-channel phase difference, For frequency; Combined with the reasonable surface wave phase velocity range of the work area The slope of the change is converted to obtain the reference slope constraint interval of the phase difference slope; the reference slope constraint interval serves as the geological reference for unwrapping verification and periodic repositioning.

6. The constraint untangling method for inter-channel phase difference in a micro-motion acquisition device according to claim 1, characterized in that, Step 4 includes: Using the median of the unwrapped constraint interval as the reference slope, and taking the folded phase corresponding to the initial frequency as the starting point, an ideal reference phase that linearly varies with frequency is generated as follows: in, For an ideal reference phase line, The starting frequency, For reference slope, For frequency Starting frequency The corresponding folded phase; For each frequency point, calculate the difference between the folded phase and the reference phase, and match the nearest... Period, to obtain the initial untangling phase ; in, This represents the number of period compensations for the corresponding frequency point; For the initial unwrapping phase Perform a first-order linear fit to obtain the actual slope. ; like Then subtract the entire phase sequence as a whole. ;in This represents the maximum value within the untangling constraint interval; like Then add to the entire phase sequence as a whole. Repeat the fitting and verification process until the slope falls within the unwrapping constraint range, and output the final constrained unwrapping phase sequence.

7. The constraint untangling method for inter-channel phase difference in a micro-motion acquisition device according to claim 1, characterized in that, Step 5 includes: By performing an oblique linear shift on the constrained unwrapped phase sequence, the phase slope is pulled back to the reference geological velocity range, resulting in the corrected phase: in, The phase after repositioning. This is the initial untangling phase. For periodic repositioning quantity, The starting frequency, To analyze the frequency band bandwidth, For frequency; A linear fit is performed on the repositioned phase to obtain the intercept. The intercept is subtracted from the whole to make the phase curve pass through the zero frequency point, eliminating the systematic intercept offset, and the final true inter-channel phase difference curve is obtained. The true inter-channel phase difference curve conforms to the SEG-2 and SAC industry standard data formats and is used for subsequent surface wave dispersion curve extraction, dispersion fitting and formation velocity inversion.

8. A constraint untangling device for inter-channel phase difference in a micro-motion acquisition device, characterized in that, include: Data input unit, core processing unit, human-computer interaction unit, and data storage unit; The data input unit is used to import the original micro-motion time series acquired simultaneously from two channels and transmit the original micro-motion time series to the core processing unit. The core processing unit includes: a cross-spectral phase extraction and polarity correction module, a constraint interval adaptation module, a global constraint unwrapping module, and a return output module, which sequentially complete steps 1 to 5 in claim 1 and output the final true inter-channel phase difference data. The human-computer interaction unit is used to configure track spacing, analyze frequency band range, period repositioning amount, upper and lower limits of constraint interval, and display the original folded phase, unwrapped phase curve, and fitting slope in real time, supporting operators to adjust parameters and recalculate. The data storage unit is used to store the original phase data, unwrapping intermediate results, slope parameters, and final phase difference curves, and supports data export in industry standard formats.

9. The constraint untangling device for inter-channel phase difference in a micro-motion acquisition device according to claim 8, characterized in that, The cross-spectral phase extraction and polarity correction module is also used to perform mean removal, linear trend removal, and segmented windowing processing on the two synchronously acquired micro-motion raw time series to obtain the first processing result and the second processing result. The i-th segment of time domain data of the first processing result and the second processing result are respectively subjected to fast Fourier transform to obtain the first frequency domain sequence and the second frequency domain sequence. The cross-power spectrum of the first and second frequency domain sequences is calculated for each segment. The cross-power spectra of all segments are averaged to obtain a smoothed cross-power spectrum. The argument of the smoothed cross-power spectrum is extracted to obtain the folded cross-power spectrum. The original folded phase sequence within the interval.

10. A computer device, comprising a memory and a processor, characterized in that, The memory stores a computer program, and when the processor executes the computer program, it implements the steps of the constraint untangling method for inter-channel phase difference of the micro-motion acquisition device as described in any one of claims 1 to 7.

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