90 results about "Velocity spectrum" patented technology

The invention discloses a method for acquiring the seismic velocity in a thin reservoir layer through well control. The method comprises the following steps of: selecting a standard single well velocity model and acquiring a corresponding logging acoustic time difference; acquiring a stacking velocity spectrum for seismic data imaging treatment and generating a stacking velocity data volume; selecting a time step length of 15-20 ms and carrying out velocity conversion on the logging acoustic time difference to obtain the velocity of a logging layer; converting the stacking velocity data volume into a logging-seismic joint forecast interval-velocity data volume; carrying out hierarchic and segmental error correction calculation on the velocity of the logging layer and the logging-seismic joint forecast interval-velocity data volume by adopting a ratio method to generate planar correction coefficients corresponding to various layers in different depths; and hierarchically and segmentally applying the planar correction coefficients to the logging-seismic joint forecast interval-velocity data volume of each layer correspondingly from top to bottom so as to obtain a high-accuracy seismic interval velocity data volume. The embodiment of the invention verifies that the method and the device for acquiring the seismic velocity in the thin reservoir layer through well control are beneficial to improvement of the forecast accuracy of the seismic velocity in the thin reservoir layer and can be used for obtaining velocity data with higher reliability.

The invention discloses a method for determining an optimum velocity section for pre-stack time migration in the processing of petroleum earthquake data. The method comprises the following steps of: forming a group of functions of the velocity which varies along with the reflection time of the earthquake wave for the central velocity by taking the velocity which varies along with the reflection time of earthquake wave as the central velocity and the velocity interval which varies along with the reflection time of the earthquake wave as the varying step length; performing pre-stack migration on the acquired earthquake data, wherein the result varies along with the velocity and is listed in the form of velocity spectrum; and generating the determined pre-stack time migration on a common reflection point into the optimum velocity section for the pre-stack time migration according to the strength and distribution of an energy ball on the velocity spectrum, and the optimum velocity of the re-stack time migration on a gather. By calculating the information needing to be output on a velocity analysis point in a valid velocity range, the method obviously reduces the calculation amount and improves the practicability.

The invention relates to a simulation test method of a rotating outer ring / fixed inner ring rolling bearing. The bearing test device is composed of a drive motor (1), a coupling (2), a rear pivot bearing (3), an outer ring shaft (4), a front pivot bearing (5), a sliding guide rail (6), a loading hydro-cylinder (8), a hinge I (9), an inner ring shaft (10), a hinge II (11), a spring (12) and a loading sleeve (13), wherein the outer ring of a test bearing (7) is installed in a cantilever end outer sleeve of the outer ring shaft; the inner ring of the test bearing is installed on the inner ring shaft; the inner ring shaft is fixed on the loading sleeve; the loading hydro-cylinder directly loads the test bearing in the radial direction by using the loading sleeve; and the axial holddown spring, the sliding guide rail, the hinge II and the like are utilized to realize axial positioning of the test bearing and reduce the interference of the radial force, thereby completely simulating the simulation test method of the rotating outer ring / fixed inner ring rolling bearing. The invention can be used for carrying out property simulation tests on the test bearing according to the velocity spectrum and loading spectrum.

The invention relates to a high-precision anisotropy speed analysis and a dynamic correction method, which comprise the following steps: preparation of seismic data: CMP seismic data gather is sorted; hyperbolic equation is adopted to perform the speed analysis without stretching influence on the small geophone offset reflected wave data; interactive interpretation is performed for velocity spectrum so as to obtain the hyperbolic velocity of the reflected wave; interval velocity is calculated with a non-delamination optimization method according to the two-way time and the hyperbolic velocity of the reflected wave; an exclusive interval velocity is calculated according to a least squares optimization principle; a vertical root mean square velocity is calculated; all geophone offset data is used for performing the anisotropy speed analysis without the stretching influence to obtain the anisotropy parameters; higher-precision root mean square and anisotropy parameters are calculated; anisotropy dynamic correction is performed; the calculation of the vertical root mean square velocity is automatically completed according to the calculated hyperbolic velocity and the offset range so as to perform the anisotropy velocity analysis and dynamic correction. The parameters obtained by calculating are free from being influenced by the dynamic correction stretching and have the advantages of high precision and high efficiency.

The invention provides a method for optimizing seismic velocity analysis data in oil and gas exploration. The method for optimizing the seismic velocity analysis data in the oil and gas exploration includes the following steps: velocity trace gather sorting is carried out on the seismic data, and an ultra trace gather used for velocity analysis is sorted out; sub-band abnormal amplitude attenuation is carried out; F-X-Y domain three-dimensional prestack random noise attenuation is carried out; frequency filtering is carried out, so that energy of a superiority frequency band of reflection waves can be enhanced; and wavelet shaping deconvolution processing is carried out to improve resolution. The method for optimizing the seismic velocity analysis data in the oil and gas exploration solves the problems that in the prior art, focusing of an energy group in velocity analysis is poor and precision is low, and has the advantages that effective reflection energy can be enhanced, the quality of the velocity analysis data is improved, the signal-to-noise ratio and the resolution of the velocity analysis trace gather are improved, and the focusing property of a velocity spectrum can be improved.

The invention provides a road trip mode distinguishing method and system based on a smart phone. The method includes the steps that an acceleration spectrum corresponding to acceleration frequency of vibration of an owner of the smart phone under various trip modes is divided into a plurality of subsections, and each subsection corresponds to one trip mode; a velocity spectrum of speed frequency characteristics of the owner of the smart phone under the various trip modes is divided into a plurality of subsections, and each subsection corresponds to one trip mode; acceleration information of vibration of the owner of the smart phone within a certain period of time is collected to obtain an acceleration data array within the period of time and further obtain a spectrum density average value according to data in the acceleration data array; longitude information and latitude information of the owner of the smart phone within a certain period of time are collected and the average speed of the owner of the smart phone can be obtained; the subsections of the acceleration spectrum which the spectrum density average value belongs to and the subsections of the velocity spectrum which the average speed belongs to are judged, and the specific trip mode can be obtained according to the two judging results.

The invention relates to a two-dimensional two-step correction method of a stacking velocity and a root-mean-square velocity field, which comprises the steps of: firstly, acquiring the time difference delta T of each measuring line before correcting a T0 curve surface and a T0 in a closing way; correcting the stacking velocity with the delta T on reference plane, wherein when the delta T is larger than 0, a correction velocity uses a ground surface filling velocity, and when the delta T is less than 0, the correction velocity uses a velocity on a velocity spectrum; and aiming at the root-mean-square velocity closing error caused by apparent dip when the stacking velocity is converted into the root-mean-square velocity, firstly obtaining the time gradient of the stacking profile of a main measuring line and a communication measuring line, acquiring the apparent dip and the root-mean-square velocity of the directions of the different measuring lines, calculating the weighting coefficient at the point of intersection, interpolating and normalizing the weighting coefficient at the point of intersection, and stacking the root-mean-square velocity of the main measuring line and the communication line in a weighting way to obtain a final root-mean-square velocity field with the weighting coefficient of the directions of the different measuring lines. The method scientifically and effectively eliminates the closing error of the velocity of the intersected measuring lines, and improves the precision of the velocity field of a two-dimensional earthquake work area.

The invention relates to a method for improving the imaging quality of seismic data. The method comprises the following steps: acquiring pre-stacking CMP gather seismic record through seismic collection; analyzing the velocity of the CMP gather; picking up optimum TV pairs in a velocity spectrum, carrying out interpolation to obtain all corresponding velocity and making dynamic correction; stacking the CMP gathers after the dynamic correction; and obtaining a post-stacking seismic section with higher imaging quality. The invention provides time plot calculation suitable for the velocity analysis and dynamic correction of an observation system with a large shot-geophone distance, and solves the problem of large shot-geophone distance without increasing the amount of calculation basically.

The invention relates to a technique for processing petroleum geophysical prospecting seismic data, which is a method for improving the velocity spectrum resolution by using phase information. The method comprises the following steps of: stimulating and recording seismic waves to obtain a common midpoint gather; performing a first-order derivative operation along a time direction, and performing Hilbert transform to obtain a complex seismic trace; superimposing P(t) traces to obtain the optimal velocity of normal moveout correction (NMO); calculating a velocity spectrum by using a conventional velocity analysis method; and performing side lobe suppression on the selected common midpoint (CMP) for velocity analysis and each time sample vector in SPS to finally obtain the velocity spectrum. By the method, influences on the velocity analysis due to amplitude changes can be avoided, the distribution of noises is converted into the distribution with gauss distribution characteristics, so that influences on the velocity analysis due to abnormal noises can be effectively inhibited, and the resolution of the velocity spectrum and the accuracy of the velocity analysis are improved.

The invention relates to an imaging velocity analysis method of seismic scattering P-P waves. The method comprises the following steps of: (1) reading seismic data into a two-dimensional array F, meanwhile, loading a parameter of an observation system into a trace header of original seismic data, and working out the position and coordinates of a scattering point according to the observation system and an acquired parameter; (2) randomly selecting a velocity vk on a shot set according to a scattered wave time-distance hyperbolic equation under the condition of fixed t0i, wherein the velocity can be used for determining a hyperbolic trace, and scattering amplitudes on all shot-geophone distances are superposed or correlated along the hyperbolic trace; then weighting and summating energies of the same scattering point to obtain a corresponding average amplitude; (3) manufacturing a velocity spectrum, wherein a series of vertical two-way travel time is firstly selected. The invention has the characteristics of increasing the superposition numbers of times of the velocity analysis technology, effectively improving the signal to noise ratio and more precisely obtaining the imaging velocity.

The invention discloses an audio detection method and device and a storage medium. The audio detection method comprises the following steps that audio signal separation is carried out on audio to be detected so as to obtain a harmonic signal and an impact signal of the audio to be detected, and a Mel frequency spectrum of the impact signal is obtained; an initial envelope of the impact signal is calculated according to the Mel frequency spectrum; an autocorrelation velocity spectrum of the initial envelope is obtained according to the initial envelope of the impact signal; and a rhythm intensity value of the audio to be detected is determined according to a sub-peak peak value in the autocorrelation velocity spectrum. According to the audio detection method and device, by analyzing the regularity and intensity of occurrence of strong impact points or strong impact points in the audio, the rhythm intensity value of an audio segment is given, so that the rhythm intensity value is more inline with the auditory feeling of a user.

The invention relates to a stacking velocity spectrum pickup method based on deep reinforcement learning and a processing terminal. The method comprises the following steps of: S1, acquiring originalcommon midpoint gathers data including seismic reflection waves, and calculating a stacking velocity spectrum composed of optimal scanning speeds at various moments; S2: inputting the stacking velocity spectrum into an auto-encoding network to obtain coded high-order energy group features; S3: inputting the codes of the high-order energy group features into a policy network, picking up the optimalscanning speeds at various moments, and outputting a speed sequence; S4: evaluating the speed sequence and outputting reward values; S5: training the policy network according to the reward values; and S6: executing theS3 to the S5 iteratively until the set maximum reward value is acquired in the S4, and then outputting the optimal speed sequence. According to the stacking velocity spectrum pickupmethod based on deep reinforcement learning and the processing terminal, intelligent velocity spectrum pickup is realized without manual intervention, the interference of multiple waves can be eliminated during the pickup process, and the obtained stacking velocity curve is more accurate.

The invention belongs to the field of test, measurement and calibration of sensors, and in particular relates to a system and a method for testing the sensitivity of an acoustic emission sensor. A system for testing the acoustic emission sensor based on a laser Doppler principle is used for testing the sensitivity of the acoustic emission sensor; and a sensitivity curve of the acoustic emission sensor is obtained according to a voltage spectrum and a velocity spectrum of the acoustic emission sensor which are measured by the system; and the displacement or displacement velocity of acoustic emission elastic waves is directly measured, accuracy of dozens of picometers can be achieved, the measured physical quantity can be traced to the source of time frequency, and a high-accuracy method is provided for testing the sensitivity of the acoustic emission sensor.

A multiple wave matching attenuation method based on optimized phase axis tracking belongs to the field of seismic multiple wave attenuation. The method comprises the following steps: firstly, giving the phase axis density Nm and the spectrum energy threshold E0; then applying a surface-related multiple prediction (SRMP) method to an original record to obtain a multiple wave record as an initial record; using optimized phase axis tracking technology and a short time window FK fan filtering method to iteratively extract and attenuate a multiple wave phase axis until the amplitude maximum of a residual multiple wave stacking velocity spectrum is less than E0; and thereby obtaining a primary wave record after multiple wave attenuation. The method carries out matching attenuation according to the direction of the multiple wave phase axis, is not affected by the predicted multiple wave signal amplitude difference and waveform change, can more or less overcome the defect that Wiener filtering methods are likely to damage a primary signal, and can significantly improve the attenuation effect of far-offset channel multiple wave signals.

The invention relates to an accurate seismic structure imaging method for reflected wave seismic data processing. The method comprises: migrating data to acquire common reflection point gather data; subjecting the common reflection point gather data to cutting, energy balance, trace interpolation and bandpass filtering processing sequentially; calculating a migration residual velocity spectrum byusing the velocity value of each common depth point in prestack time migration velocity field at a fixed time interval; the performing energy balancing processing; determining a residual velocity value of the largest energy at each time by using the calculated migration residual velocity spectrum; and updating the migration velocity field of a corresponding position to obtain an accurate prestacktime migration velocity field and an accurate seismic structure image. The accurate seismic structure imaging method can obtain a high resolution residual velocity spectrum, provides a reliable basisfor more accurate prestack time migration structure imaging and is suitable for imaging continental sedimentary basin late violent tectonic movement and layered transverse medium uneven structures.

The invention provides a well-constrained velocity spectrum pickup method for low-SNR (signal-to-noise ratio) seismic data, and belongs to the field of seismic data processing. The method comprises (1), well logging preprocessing: input interval transit time or acoustic velocity is corrected, and a corrected acoustic velocity is obtained; (2), acoustic logging data shallow layer compensation and downward extension processing are performed on the corrected acoustic velocity, and the acoustic velocity subjected to shallow layer compensation and downward extension is obtained; (3), time-depth conversion is performed on the acoustic velocity subjected to shallow layer compensation and downward continuation to obtain an interval velocity, and the interval velocity is subjected to root-mean-square velocity conversion to obtain a root-mean-square velocity; (4), projection of the root-mean-square velocity on the velocity spectrum is acquired. With adoption of the method, pickup randomness is reduced, and the velocity pickup accuracy is improved.

The invention discloses a common converted point gathering method which comprises the following steps of: calculating the depth of a converted point according to the intersection point of a connection line between a shooting point and a geophone and a CCP bin; obtaining the velocity ratio of the converted point according to the depth domain velocity spectrum of the depth of the converted point; calculating the reflection time period of the converted wave of an input channel according to the velocity ratio of the converted point; mapping earthquake data received within the reflection time period to the CCP bin, wherein a non-hyperbolic travel time relationship is corrected into a hyperbolic travel time relationship in the mapping process; and generating hyperbolic accurate velocity ratio CCP gathering. By the invention, processing efficiency and accuracy can be improved.

The invention discloses a method for establishing a depth domain construction model. The method includes the following steps: single well correction processing and multi-well consistency processing are performed on the logging curve line; the velocity field is established layer by layer by utilizing the seismic stack velocity spectrum to establish the speed model, and time depth conversion is performed; correction is performed on the velocity field in the interval based on the error between the depth obtained by the time depth conversion and the corresponding geology layering depth of the well; and the time depth conversion is performed on the velocity field in the interval after correction again to obtain the depth domain construction model. Two aspects of the accuracy of the time domainconstruction interpretation and the rationality of the time depth conversion velocity model are improved, and the fine degree of the depth domain construction is improved.

The invention provides a seismic velocity spectrum automatic pick-up method, and belongs to the field of oil gas and coal-bed methane seismic exploration and development. The method comprises the following steps: (1) creating grid data: converting velocity spectrum data stored in a standard seismic data format into two-dimensional grid data; (2) setting a computation time window and determining a maximum value position in the area of the computation time window; (3) defining a velocity search threshold vh, moving the computation time window down by one unit, searching the maximum value Vmax in the area of the computation time window, recording the position of the maximum value Vmax (namely, recording the values of the subscripts n and k of a corresponding two-dimensional array) if the found maximum value Vmax is greater than the threshold vh, and giving up recording if the found maximum value Vmax is smaller than the threshold vh; (4) completing velocity curve connection to form a non-interpolated velocity curve; and (5) interpolating the non-interpolated velocity curve obtained in step (4) to obtain a final velocity curve.

The present invention relates to a method for detection of a sea level wave height through adoption of an S-waveband Doppler radar. The method comprises: the step 1, employing an S-waveband Doppler radar to obtain a sea echo Doppler spectrum, extracting the center frequency of the obtained N-frame Doppler spectrum, obtaining a center frequency sequence, and obtaining a measured radial speed sequence according to the Doppler effect; the step 2, removing an average value for the vertical speed measured by the radar, and performing discrete Fourier transformation and Modulo square to obtain a speed spectrum; the step 3, according to the linear wave theory, obtaining the conversion relation of the speed spectrum and a sea wave spectrum, and obtaining the sea wave spectrum; the step 5, according to the mathematic relation between the efficient wave height and the sea wave spectrum, employing the spectral moment method to obtain the wave height; and the step 5, employing the zero-moment singular value removal method to allow the abnormal efficient wave height to recover normality. The method for detection of sea level wave height through adoption of the S-waveband Doppler radar provides a new detection means for obtaining the sea level wave height through adoption of a microwave Doppler radar, has high detection precision and wave field spatial resolution, and is simple and clear in results.

A turbulence target velocity spectrum width estimation method based on space-time covariance matrix fitting comprises the steps of 1) initializing radar echo data of a to-be-detected distance unit, estimating the covariance matrix ( R <^>) of a radar echo signal based on the radar echo data of the to-be-detected distance unit received by an array, constructing a covariance matrix model RS (fo, sigma f) of a turbulence target signal of the distance unit according to the spatial taper angle of the to-be-detected distance unit, constructing a cost function, carrying out two-dimensional search ina target parameter range to find the parameter combination {f<^>o, sigma<^> f } with the maximum value of the cost function, obtaining the turbulence target velocity spectrum width estimation value ofthe distance unit by a doppler spectrum width; and 4) repeating the previous steps to process the echo data received by the radar for each distance unit one by one, and finally obtaining the turbulence target velocity spectrum width estimation result of the whole distance unit. Simulation results show that under the condition of low signal-to-noise ratio, a relatively accurate turbulence target speed spectrum width estimation result can be obtained through the method.

The invention relates to an imaging velocity analysis method of a seismic scattering P-S converted wave, comprising the following steps of: firstly, reading the seismic data of a seismic scattering P-P wave into a two-dimensional array F, and computing the position and the coordinate of a scattering point; secondly, arbitrarily selecting a velocity vPk to overlap or correlate scattering amplitudes of shot-geophone distances and weigh to sum the energy of the same scattering point so as to obtain a corresponding average amplitude; thirdly, making a seismic scattering P-P wave velocity spectrum; fourthly, reading the seismic data of the seismic scattering P-S converted wave into a two-dimensional array E, and computing the position and the coordinate of the scattering point; fifthly, taking an acquired seismic scattering P wave velocity to overlap or correlate the scattering amplitudes of the shot-geophone distances and weigh to sum the energy of the same scattering point so as to obtain the corresponding average amplitude; and sixthly, making a seismic scattering P-S converted wave velocity spectrum. The invention increases the overlapping times of a velocity analysis technology and enables the focusing capability of effective scattered wave energy to be higher.

The invention is a method for determining the optimal velocity profile of pre-stack time migration for petroleum seismic data processing. The procedure is to take the velocity that changes with the seismic wave reflection time as the central velocity, and the velocity interval that varies with the seismic wave reflection time as the change step, form a set of velocity functions with the seismic wave reflection time for the central velocity, and then pre-stack the collected seismic data. Migration, the results are listed in the form of velocity spectrum as the velocity changes, according to the energy mass intensity and distribution position on the velocity spectrum, and the optimal velocity used for prestack time migration on the gather, the prestack time determined on the common reflection point Migrating Optimal Velocity Generates a prestack time-migrated optimal velocity profile. The invention calculates the information that needs to be output at the speed analysis point within the effective speed range, which significantly reduces the calculation amount and improves the practicality.

The invention relates to an instrument and method for processing a doppler measurement signal. The instrument (100) is provided according to an embodiment of the invention. The instrument (100) includes an interface (101) configured to receive a Doppler measurement signal and a processing system (112) coupled to the interface (101) and receiving the Doppler measurement signal. The processing system (112) is configured to generate a two-sided velocity spectrum including a plurality of discrete frequency bins from the Doppler measurement signal, with the two-sided velocity spectrum distinguishing spectral elements, and process one or more velocity spectrum bin pairs against a plurality of local gate thresholds, with the one or more velocity spectrum bin pairs being substantially symmetrically located about one or more carrier wave bins and wherein each velocity spectrum bin pair is processed against a corresponding local gate threshold of the plurality of local gate thresholds.

Embodiments of the specification disclose a method, device and system for suppressing multiple waves. The method comprises the following steps: acquiring time horizons of a mark layer in a target processing layer segment; superimposing the time horizons on a superposition velocity spectrum, and picking a velocity corresponding to the marker layer on the superposition velocity spectrum; picking a superposition velocity on the superposition velocity spectrum based on the velocity corresponding to the marker layer to obtain a first optimized superposition velocity; and performing multi-wave suppression on the pre-superposition seismic trace set of the target processing layer segment based on the radon transform according to the first optimized superposition velocity to obtain seismic data after the multi-wave suppression. With the embodiments of the specification, the effect of multi-wave suppression can be improved.

The invention discloses a method for measuring a gas-liquid two-phase flow phase interface position based on a velocity matching spectrum, which comprises: an ultrasonic transceiver is mounted on a pipe wall of a pipeline provided with a gas-liquid two-phase flow; an ultrasonic transducer transmits ultrasonic pulses to the gas-liquid two-phase flow; echo signals are regulated through a diode peak value envelope detector to acquire echo envelope signals and further to acquire an echo envelope diagram; the echo envelope signal diagram is processed to acquire envelope signal datum; a two-base rapid fourier transformation algorithm is adopted to calculate the envelope signal datum to acquire a velocity spectrum; an abscissa of an intersection point between an oblique straight line corresponding to a peak value of the velocity spectrum and the echo envelope signals is the distance between the ultrasonic transducer and a reflector; and the distance is the phase interface position of the gas-liquid two-phase flow. By adopting the method provided herein, the accuracy and the reliability are high; the phase interface position of the gas-liquid two-phase flow can be measured effectively; the method can be applied to the situations that pipelines and fluids are not transparent; the distribution of the fluids inside the pipelines are not interfered; and the cost is low and the environment is not polluted.

The invention relates to a submarine multiple prediction and tracking attenuation method in a speed domain, and belongs to the field of seismic data processing and analysis. The specific implementation process of the method mainly comprises the following four steps of: 1) creating a high-resolution speed domain record; 2) predicting a seabed multiple wave velocity spectrum based on an initial speed domain record; 3) tracking a hyperbolic multiple event; and 4) utilizing multiple wave event attenuation of FK fan-shaped filtering. Compared with a conventional multiple suppression method, the method does not depend on the period of multiple waves, and does not need to carry out dynamic correction processing on an input CMP gather; multiple wave suppression is carried out in a time-space domain, and the influence of a truncation effect is avoided; meanwhile, the length of the intercepted and recorded time window can be freely set, and when the time window is relatively small, multiple waves of which the superposition speed is relatively close to that of primary waves can be attenuated, so that the primary waves are prevented from being damaged; compared with a free interface multiple attenuation method, multiple in a far offset channel can be effectively suppressed, and the method has an obvious efficiency advantage.

The invention discloses a seismic velocity spectrum automatic pickup method and device based on unsupervised learning. The method comprises the steps: acquiring a seismic stacking velocity spectrum; scanning the maximum reference stacking speed and the minimum reference stacking speed of the corridor according to a preset speed, and cutting off the acquired seismic stacking speed spectrum; carrying out normalization and threshold filtering processing on the seismic stacking velocity spectrum after removal processing to obtain a seismic stacking velocity spectrum after scatter processing; in the time direction, at each time sampling points, executing the following steps to carry out stacking velocity automatic pickup on the scattered seismic stacking velocity spectrum: constructing two subspace-time windows with an overlapping relationship in a main space-time window of each time sampling point; respectively clustering the data in the two sub space-time windows by adopting a weighted K-mean algorithm; and determining the clustering center of the main space-time window according to the clustering centers of the two sub space-time windows in the main space-time window. The method anddevice can determine the center of the velocity spectrum energy group in a self-adaptive manner.

The invention provides a velocity analysis method for multi-source seismic data processing, and belongs to the field of oil exploration. The speed analysis method comprises the following steps: selecting target lines in a work area according to intervals, and inputting a minimum velocity, a maximum velocity and a velocity increment; conducting constant-velocity scanning on the target lines respectively to obtain a series of corresponding stacked sections; according to the stacked sections, analyzing the imaging conditions of different velocities which are measured at different spatial positions of the target lines and in different periods to obtain the regularity of spatial velocity distribution in the work area; according to the combination of the regularity of the spatial velocity distribution with an energy velocity spectrum, making a velocity interpretation to obtain an initial velocity of multi-source seismic data; carrying out noise separation and velocity iteration based on the initial velocity.