55 results about "Acoustic wave equation" patented technology

The invention discloses a woodworking machine tool noise sound power level measurement method based on a sound intensity method, and belongs to the technical field of machine tool noise measurement, and the method specifically comprises the steps: determining a housing surface covered by a tool rotation plane projection as a main sound radiation region, and determining a main bearing pedestal installation surface as an infrasound radiation region; sound pressure, vibration acceleration signals and dynamic air pressure signals of a main sound radiation area are collected; resampling a dynamic air pressure signal rotation angle domain, extracting a reference pneumatic pulsating waveform synchronous with tool tooth sweeping, and establishing an airflow induced sound pressure model according to the reference pneumatic pulsating waveform and a phase relation; calculating a surface normal vibration speed according to the vibration acceleration, and establishing a structure radiation sound pressure model in combination with a sound wave equation; decomposing the sound pressure signal to obtain two types of component estimation values, and performing parameter optimization to obtain net sound intensity of a main sound radiation area; extracting vibration frequency band energy of an infrasound radiation area, calculating equivalent sound intensity by combining a sound radiation efficiency model, and outputting a total sound power level by space integration; the invention provides an effective method for accurately measuring and controlling the noise of the woodworking machine tool.

The invention discloses a voice interaction method and system based on an intelligent doll, and relates to the technical field of intelligent acoustic interaction, and the method comprises the steps: carrying out the time-frequency analysis processing of a vibration feature matrix, and generating a modal parameter set of vocal cord vibration through biomechanical modeling in combination with the human neck tissue density features; inputting the modal parameter set of vocal cord vibration into the vibration-acoustic model to generate a sound source excitation field, performing environmental noise compensation on the sound source excitation field by using the acoustic characteristic matrix, and generating a time domain pure voice signal through an acoustic wave equation; and collecting real-time position coordinates of the user, calculating and driving a piezoelectric loudspeaker array of the intelligent doll to adjust the phase according to the frequency spectrum characteristics of the time domain pure voice signal, forming a directional focusing sound field, recording user physiological feedback, and generating a user physiological feedback matrix. According to the method, the vocal cord displacement modal function vector is solved through the nonlinear integral and augmented Lagrange algorithm, so that the acquisition precision and the anti-noise capability of the voice signal are improved from the source.

The invention discloses a consequence simulation method based on water electrolysis hydrogen production, which comprises the following steps: constructing a multi-physical field coupling simulation model comprising an electric field, a thermal field, a flow field and a stress field, and setting and calibrating a geometric structure, physical property parameters, boundary conditions and a numerical strategy to obtain base field distribution of an electrode system. A bubble dynamics whole-process model is introduced, nucleation, diffusion growth and separation of bubbles are simulated, gas-liquid two-phase dynamic feedback is achieved through a volume fraction method, bubble interface force and a thermal expansion effect are coupled, and micro-crack formation of the electrode is judged by utilizing a stress criterion and a crack initiation threshold. And carrying out curing treatment on crack evolution by adopting a virtual crack unit or a phase field method. A crack propagation process is simulated in combination with a Miner criterion and a Paris law, an acoustic source item is introduced, an acoustic wave equation is solved, and the effects of full-link prediction, early warning, reliability evaluation and life optimization of electrode damage and hydrogen production performance are achieved in the operation process of the water electrolysis hydrogen production system.

The invention discloses a wind turbine blade internal damage diagnosis method based on a sound field graph neural network, and belongs to the technical field of wind turbine blade state detection, and the method comprises the steps: deploying a microphone array in a cabin, and collecting an acoustic signal when a blade rotates; constructing a space sound field graph structure by taking the microphone as a node and the sound wave propagation path as an edge; extracting nonlinear acoustic features by using a physical constraint graph neural network PC-GNN; generating a damage embedding vector based on self-supervised training contrast learning; and outputting a damage probability thermodynamic diagram and positioning information. According to the method, a directional microphone array is deployed in a cabin, and a sound wave propagation space diagram structure is constructed; designing a physical constraint graph neural network PC-GNN, and embedding an acoustic wave equation as a regularization item; the problem of scarcity of damaged samples is solved by adopting self-supervised contrast learning; and finally outputting a positioning thermodynamic diagram of the internal damage of the blade.

The invention relates to the technical field of precision measurement and instrument testing, in particular to a test error analysis method based on a high-precision acoustic phased array Doppler log, and aims to solve the problems that a traditional Doppler log mostly adopts a black box model driven by pure data, explicit modeling of a sound wave propagation and array receiving physical mechanism is lacked, and the test error analysis accuracy is poor. The problems that the generalization ability is weak under errors such as channel amplitude-phase mismatch and emission nonlinearity, real Doppler frequency shift is difficult to accurately extract, and the credibility of speed estimation cannot be quantified, so that output in a complex underwater environment is unreliable are solved. Physical priori such as an acoustic wave equation, a Doppler effect and array manifold is embedded into a neural network, physical consistent modeling and efficient reasoning of multi-channel echoes are achieved, an uncertainty quantification mechanism based on the evidence theory is further introduced, and the reliability and the likelihood of velocity estimation are dynamically evaluated, so that the reliability and the reliability of velocity estimation are improved. And the robustness and interpretability of the system in a complex underwater environment are effectively improved.

The invention provides an anisotropic medium pure acoustic wave least square reverse time migration method, and relates to the field of data processing and oil and gas geophysical exploration, and the method comprises the steps: calculating an anisotropic medium pure acoustic wave equation demigration operator; determining an anisotropic medium pure acoustic wave equation adjoint equation and a parameter disturbance gradient formula; solving an anisotropic medium pure acoustic wave equation demigration operator and an adjoint equation; determining an anisotropic medium pure acoustic wave equation Hessian matrix and vector product formula; calculating a model parameter disturbance gradient and a Gaussian-Newton gradient precondition; and iteratively updating the speed and the anisotropic parameter disturbance model. Through Gaussian-Newton Hessian operator gradient preconditions, crosstalk of disturbance of different model parameters is suppressed, a speed and anisotropy parameter disturbance model is established, an efficient and accurate imaging analysis tool is provided for seismic exploration and acquisition in a complex area, the migration imaging effect of anisotropic medium seismic data is improved, and the method is suitable for the seismic exploration and acquisition of the complex area. And the imaging precision and the convergence speed of the pure acoustic wave least square reverse time migration of the anisotropic medium are improved.

This invention provides a method, system, and storage medium for enhancing transformer fault acoustic signature diagnostic samples. The method includes: constructing the acoustic wave equation for the vibration of the core and windings propagating through the medium and the medium interface boundary conditions; performing sound field simulation on a fault model based on the acoustic wave equation and the medium interface boundary conditions to obtain a fault simulation sound field; determining a physical simulation dataset based on the fault simulation sound field; performing sparse representation on the physical simulation dataset to obtain a sparse dictionary and a sparse coefficient matrix; performing transfer learning on real fault samples to obtain a transfer dictionary; and performing sample enhancement based on the sparse dictionary, the sparse coefficient matrix, and the transfer dictionary to obtain enhanced transformer fault acoustic signature samples. In this embodiment, sample enhancement using the sparse dictionary, the sparse coefficient matrix, and the transfer dictionary effectively enhances the samples of transformer faults.

The invention discloses a three-dimensional seismic wave field continuation method and device of an optimization strategy, and relates to the technical field of seismic exploration processing. Based on a polynomial expansion strategy, obtaining an approximation form of a pure acoustic wave frequency dispersion relational expression of the three-dimensional VTI medium, wherein the approximation form comprises a polynomial coefficient; constructing an optimized pure sound wave frequency dispersion relation of the three-dimensional VTI medium through wave number combination by using a sampling approximate optimization strategy; obtaining a pure acoustic wave dispersion relation suitable for a three-dimensional TTI (Transmission Time Interval) medium through coordinate rotation operation; the pure acoustic wave frequency dispersion relation of the three-dimensional TTI medium is converted to a time-space domain, a time-space domain pure acoustic wave equation of the three-dimensional TTI medium is formed, and an improved anisotropic Poisson algorithm and a finite difference method are introduced to be combined for solving; and realizing simulation of the seismic wave field in the three-dimensional TTI medium based on numerical solution of a time-space domain pure acoustic wave equation of the three-dimensional TTI medium. The problem of how to simulate the propagation process of seismic waves in a three-dimensional complex anisotropic medium so as to improve the precision and reliability of seismic exploration is solved.

This invention discloses a method for measuring the sound power level of woodworking machine tool noise based on the sound intensity method, belonging to the field of machine tool noise measurement technology. Specifically, it includes: determining the housing surface covered by the projection of the tool's rotation plane as the main sound radiation area, and the main bearing seat mounting surface as the secondary sound radiation area; acquiring sound pressure, vibration acceleration signals, and dynamic air pressure signals in the main sound radiation area; resampling the dynamic air pressure signal in the rotational angular domain, extracting the reference air pulse waveform synchronized with the tool tooth sweep, and establishing an airflow-induced sound pressure model based on this and the phase relationship; calculating the surface normal vibration velocity based on the vibration acceleration, and establishing a structural radiation sound pressure model based on the sound wave equation; decomposing the sound pressure signal to obtain estimates of two types of components, and obtaining the net sound intensity of the main sound radiation area after parameter optimization; extracting the vibration frequency band energy of the secondary sound radiation area, calculating the equivalent sound intensity based on the sound radiation efficiency model, and spatially integrating to output the total sound power level. This invention provides an effective method for the accurate measurement and control of woodworking machine tool noise.

The invention discloses a seismic wave field simulation method and system in an attenuation medium. A new constant Q viscous sound wave equation is constructed to accurately meet the dispersion relation of the Kjartansson constant Q theory, and an amplitude attenuation item and a phase dispersion item are subjected to explicit separation, so that complete decoupling of attenuation and dispersion can be realized while the theoretically accurate constant Q dispersion relation is kept, and the frequency dispersion accuracy is improved. And solving a constant Q viscous acoustic wave equation through a generalized pseudo-spectral numerical simulation method based on space Fourier transform to obtain a seismic wave field with spatio-temporal variation, so that the precision of viscous acoustic wave simulation is remarkably improved.

The invention provides an imaging method for a high and steep structure, and the method comprises the steps: inputting a velocity field, and building an observation system; constructing an optimal nine-point difference format of the frequency domain acoustic wave equation; prism waves are constructed according to the bon theory; separating uplink and downlink waves; and outputting an imaging result. A novel frequency domain prismatic wave reverse time migration imaging method is provided, and a frequency sound wave prismatic wave reverse time migration algorithm is realized. The prismatic wave reverse time migration performs high-resolution imaging on underground high and steep structures, and provides more reliable data support for geological exploration.

The present invention belongs to the field of exploration geophysics, and discloses a sonic vector reverse time migration imaging method without the influence of reflection angle, which comprises the following steps: presetting a seismic wavelet and an initial velocity model, and realizing the forward extrapolation of the sonic wave field by using the first-order acoustic wave equation to obtain the sonic source wave field; according to the observed seismic data and the preset initial velocity model, realizing the backward extrapolation of the sonic wave field by using the first-order acoustic wave equation to obtain the sonic receiver wave field; based on the sonic source wave field and the sonic receiver wave field, determining the imaging angle by using the constructed imaging angle extraction function based on the energy norm; and performing imaging by using the constructed dot product cross-correlation imaging condition without the influence of reflection angle to obtain a scalar imaging result without the influence of reflection angle. The method disclosed by the present invention can eliminate the polarity inversion problem caused by the imaging angle in the sonic vector dot product imaging condition, improve the polarity consistency of the sonic imaging isophase axis, and thus guarantee the accuracy of geological structure imaging in a complex environment.

The invention belongs to the technical field of geophysics, and discloses a random geologic model seismic wave efficient simulation method, system and device and a medium, and the method comprises the steps: obtaining a to-be-processed geologic model; constructing a two-dimensional first-order variable density acoustic wave equation corresponding to the geologic model through a Newton's law and a matter state equation; carrying out approximate processing on the two-dimensional first-order variable-density acoustic wave equation by utilizing a staggered grid finite difference analysis method based on a derivative multiplication rule; calculating a staggered grid finite difference operator based on a preset precision requirement; and discretizing the two-dimensional first-order variable-density acoustic wave equation by adopting a staggered grid finite difference operator, constructing a corresponding discrete format, and carrying out seismic wave forward modeling simulation. According to the technical scheme, the numerical simulation time can be shortened under the condition that the precision is not lost.

The invention discloses a frequency modulation sound wave generation method of a differential evolution algorithm based on individual search optimization technology integration. Comprising the steps of collecting original audio and constructing a frequency modulation sound wave equation; generating a population and establishing a fitness function, dividing the population into two branch populations, and performing adaptive optimization by using two population optimization methods; setting dominant and auxiliary methods, and dividing dominant and auxiliary groups in one-to-one correspondence; the current individual search optimization technology is used for processing individuals which are poor in adaptive value and long in service life in the optimized population, and the individual search optimization technology is adjusted according to the processing result; if the last-stage stagnation occurs, processing the optimal individual by using an elite individual search optimization technology to obtain a new population; otherwise, taking the population after secondary optimization as a new population; and iterating until the evaluation times reach a preset threshold value, inputting the optimal individual into a frequency modulation sound wave equation, and generating frequency modulation sound waves. The problem of local optimum in the frequency modulation sound wave generation process can be effectively avoided.

The invention relates to the field of seismic exploration, and discloses an earth medium sound wave scattering wave field holographic numerical simulation method and system and a storage medium, and the method comprises the steps: setting a time domain sound wave equation aiming at the characteristics of an earth medium; dividing the time domain acoustic wave equation into a background wave field equation and a scattered wave field equation based on velocity field separation and background field and scattered field separation; obtaining a time domain scattering wave field wave equation based on the scattering wave field equation; determining a spatial wave number mixed domain scattered wave equation set in the frequency domain based on the time domain scattered wave field wave equation; and calculating spatial domain scattering wave field distribution based on the spatial wave number mixed domain scattering wave equation set in the frequency domain as a holographic numerical simulation result of the earth medium sound wave scattering wave field. Therefore, the sound wave numerical simulation model is established according to the characteristics of the earth medium, and the consistency of the external boundary of the model and the real boundary condition is ensured, so that the accurate holographic numerical simulation of the earth medium sound wave scattering wave field is realized.

The invention discloses a meshless seismic wave forward modeling method based on a difference numerical method and related equipment, and belongs to the field of exploration geophysics. According to the method, flexible mesh generation is carried out based on an undulating surface seismic wave speed model, a surface interface is completely fitted, and a high-precision difference coefficient set is obtained without manually selecting deformation parameters; by adding a filter related to a second-order time item in a two-dimensional scalar time domain acoustic wave equation, the robustness and accuracy of numerical simulation are effectively improved, so that a high-precision and stable seismic wave numerical simulation result is obtained, the precision and stability of seismic data processing can be effectively improved by utilizing the method, and the seismic data processing efficiency is improved. The method provides solid technical support for loess tableland seismic wave forward modeling, and has important practical significance for evaluating the influence of the earth surface effect on exploration data in the loess tableland, improving the accuracy and reliability of the exploration data, analyzing the physical properties and change rules of underground media and simulating the physical properties and seismic wave propagation conditions of underground structures.

The invention discloses a seismic wave numerical simulation method based on k-space compensation and a related device, and belongs to the technical field of oil exploration. The method comprises the following steps: constructing a first-order fractional order Laplace viscous acoustic wave equation of a seismic wave field, and deducing a viscous acoustic wave equation only containing velocity field variables according to the first-order fractional order Laplace viscous acoustic wave equation; converting the viscous acoustic wave equation only containing the velocity field variable into a viscous acoustic wave equation only containing the displacement field variable; deducing a recursion formula of the displacement field according to the viscous acoustic wave equation only containing the displacement field variable, and further obtaining a k-space compensation-based wave field recursion formula according to the recursion formula of the displacement field; and obtaining seismic wave field parameters and underground medium parameters, and inputting the seismic wave field parameters and the underground medium parameters into a k-space compensation-based wave field recursion formula to obtain a seismic wave numerical simulation result. According to the method, the time accumulation error can be effectively suppressed, so that the method is suitable for a larger time step length; and excessive extra calculation amount is not introduced, so that the method is more efficient on the premise of ensuring the precision.

The application discloses a VSP acoustic wave full waveform inversion method of a double-branch physical driving cyclic neural network, applied to the field of seismic data processing, and aims at the problems of weak explanation and high calculation cost of the existing seismic velocity inversion technology in a full data driving mode. Since a wave equation describes the change of a wave field in time and space, a time stepping method is adopted in numerical simulation, that is, the wave field state of the next moment is calculated according to the state of the previous moment. Thus, the wave field state of the previous moment is taken as a hidden layer of the RNN, the acoustic wave equation is solved by finite difference, and the velocity parameter in the equation is taken as a trainable parameter in the physical driving RNN forward network. The shot record output by the physical driving RNN forward network each time is taken as a predicted value. The shot record output by the physical driving RNN forward network by setting a real velocity parameter is taken as an observed value. The process of correcting the velocity parameter by reverse propagation of the loss between the predicted value and the observed value is called a velocity inversion process.

This invention discloses a method and apparatus for audio line status identification in communication equipment rooms. The method includes audio data acquisition, acoustic physical constraint modeling, multi-region acoustic feature importance classification, audio line status identification model design, constraint loss dynamic balance optimization, acoustic feature loss function construction, and audio line status identification. This invention belongs to the field of data processing technology, specifically referring to a method and apparatus for audio line status identification in communication equipment rooms. This scheme models the sound wave propagation in the equipment room based on a three-dimensional acoustic wave equation to suppress non-fault noise interference; it divides the equipment room into zones, quantitatively allocates the number of monitoring points and regional loss weights, focuses on core areas, and significantly improves the fault detection rate of critical lines; it introduces the measured background noise sound pressure level of the equipment room to construct a noise correction coefficient, significantly improving the robustness of fault identification; and it designs an exponential dynamic relaxation coefficient, combined with benchmark weight allocation, to further enhance the early fault detection capability in critical areas.

This application relates to the field of geological exploration technology and discloses a reverse-time migration method and electronic equipment. The reverse-time migration method includes: acquiring seismic exploration data in a viscoelastic medium; calculating a compensated backpropagation wavefield based on the inverse dispersion acoustic wave equation transformed to the frequency domain and the seismic exploration data; and obtaining a compensated reverse-time migration image based on the compensated forward propagation wavefield and the compensated backpropagation wavefield. By acquiring seismic exploration data in a viscoelastic medium, calculating a compensated backpropagation wavefield based on the inverse dispersion acoustic wave equation transformed to the frequency domain and the seismic exploration data, and obtaining a compensated reverse-time migration image based on the compensated forward propagation wavefield and the compensated backpropagation wavefield, this application can compensate for energy loss caused by absorption attenuation during the reverse-time migration process while suppressing high-frequency noise, ensuring the stability of the reverse-time migration results.

The invention discloses a stable and efficient seismic wave propagation vector determination method and device. The method comprises the following steps: solving a sound wave fluctuation equation according to a finite difference method to obtain seismic wave field data; calculating a spatial domain gradient of a seismic wave field at a certain moment, a time domain integral of the seismic wave field at a certain moment and a spatial domain gradient of the time domain integral of the seismic wave field at a certain moment based on the seismic wave field data; and finally determining a seismic wave propagation vector according to the seismic wave field data, the spatial domain gradient of the seismic wave field at a certain moment, the time domain integral of the seismic wave field at a certain moment and the spatial domain gradient of the time domain integral of the seismic wave field at a certain moment. Compared with the traditional Poynting vector, the method has the advantages that the oscillation phenomenon of the traditional Poynting vector is eliminated, and the calculation complexity is relatively low.

The invention provides a transformer fault voiceprint diagnosis sample enhancement method, a transformer fault voiceprint diagnosis sample enhancement system and a storage medium. The method comprises the following steps: constructing an acoustic wave equation of vibration of an iron core and a winding in medium propagation and a medium interface boundary condition; performing sound field simulation on the fault model according to the acoustic wave equation and the medium interface boundary condition to obtain a fault simulation sound field, and determining a physical simulation data set according to the fault simulation sound field; carrying out sparse representation on the physical simulation data set to obtain a sparse dictionary and a sparse coefficient matrix, and carrying out transfer learning on a real fault sample to obtain a transfer dictionary; and performing sample enhancement according to the sparse dictionary, the sparse coefficient matrix and the migration dictionary to obtain a transformer fault voiceprint enhancement sample. According to the embodiment of the invention, the sample enhancement is carried out through the sparse dictionary, the sparse coefficient matrix and the migration dictionary, and the sample enhancement effect of the transformer fault sample can be effectively realized.

The application belongs to the technical field of petroleum geophysical exploration, and particularly relates to a moving medium seismic wave forward simulation method. The flowing property of seawater is introduced into an acoustic wave equation to construct a moving medium acoustic wave equation, and the equation can more accurately simulate the propagation of seismic waves in flowing seawater and stationary solid rock layers.

This disclosure relates to a method, apparatus, device, storage medium, and computer program for establishing a depth domain velocity model. The method includes: acquiring pre-stack seismic shot gather data for the current region; outputting velocity updates based on the pre-stack seismic shot gather data using a pre-trained initial depth domain velocity model; acquiring updated velocities based on the updated velocities; performing acoustic wave equation forward modeling on the updated velocities according to preset forward modeling parameters to obtain forward modeling records; establishing a L2-norm target loss function based on the forward modeling records and pre-acquired observation records; performing iterative inversion on the initial depth domain velocity model using the L2-norm target loss function; confirming the depth domain velocity model after reaching a preset number of iterations; and performing depth domain velocity analysis using the depth domain velocity model based on seismic data for the target region to obtain velocity data.

The invention belongs to the technical field of multiple wave imaging based on a one-way acoustic wave equation, and relates to a multiple wave joint migration inversion method aiming at a stratum attenuation effect, aiming at the attenuation effect existing in actual seismic exploration and combining the multiple wave imaging advantages of a joint migration inversion algorithm, the deep part energy and the resolution of a reflectivity migration ground are improved, and the stratum attenuation effect is improved. The shallow artifacts of the speed inversion result are eliminated, and the precision of the speed model is improved. The method comprises the following steps: picking up an initial velocity model and a reflectivity model through preprocessing according to obtained observation data; in each iteration, simulation data are obtained through full wave field simulation containing an attenuation effect, a wave field residual error is obtained by making a difference between the simulation data and observation data, and linear iteration updating is carried out on parameters through a gradient descent method; the reverse extrapolation of the wave field residual error can be mapped on the gradient of the propagation operator, and the gradient is converted into a velocity gradient through linear parameterization; in continuous iteration, the residual error between simulation data and observation data is minimized, and a satisfactory imaging result is obtained.

The application discloses a three-dimensional anisotropic medium space-time domain seismic forward method, device, medium and product, relates to the technical field of forward simulation of geophysical exploration, and comprises the following steps: based on a preset improved time high-order difference operator and a preset improved space high-order difference operator, respectively discretizing time derivatives and space derivatives in a three-dimensional VTI medium acoustic wave equation; based on the three-dimensional VTI medium acoustic wave equation, simplifying time-discrete functions and space-discrete functions to obtain a simplified space-time domain dispersion relation; based on a target optimization algorithm, solving the simplified space-time domain dispersion relation to obtain optimized time item high-order difference coefficients and optimized space item high-order difference coefficients; and based on the optimized time item high-order difference coefficients, the optimized space item high-order difference coefficients, the time-discrete functions and the space-discrete functions, extrapolating and solving the three-dimensional VTI medium acoustic wave equation. The application can effectively improve the numerical precision in anisotropic wave field simulation.

The application discloses a voice interaction method and system based on an intelligent doll, relates to the technical field of intelligent acoustic interaction, and comprises the following steps: performing time-frequency analysis and processing on a vibration feature matrix, combining with the density characteristics of human neck tissues, and generating a modal parameter set of vocal cord vibration through biomechanical modeling; inputting the modal parameter set of vocal cord vibration into a vibration-acoustic model to generate a sound source excitation field, compensating the sound source excitation field for environmental noise by using an acoustic feature matrix, and generating a time-domain pure speech signal through a sound wave equation; collecting real-time position coordinates of a user, calculating and driving a piezoelectric loudspeaker array of the intelligent doll to adjust a phase according to the spectral characteristics of the time-domain pure speech signal, forming a directional focused sound field, recording physiological feedback of the user, and generating a user physiological feedback matrix. The application solves a vocal cord displacement modal function vector by using a nonlinear integral and an augmented Lagrange algorithm, so that the collection accuracy and the noise resistance of a speech signal are improved at the source.

The invention belongs to the field of exploration geophysics, and discloses a reflection angle influence-free sound wave vector reverse time migration imaging method, which comprises the following steps of: presetting seismic wavelets and an initial speed model, and realizing forward extrapolation of a sound wave field by utilizing a first-order sound wave equation to obtain a sound wave source wave field; according to observed seismic data and a preset initial velocity model, using a first-order sound wave equation to realize sound wave field reverse extrapolation to obtain a sound wave detection wave field; based on the sound wave source wave field and the sound wave detection wave field, an imaging angle is determined by using the constructed energy norm-based imaging angle extraction function; and based on the imaging angle, imaging is carried out by using the constructed dot product cross-correlation imaging condition without the influence of the reflection angle, and a scalar imaging result without the influence of the reflection angle is obtained. According to the method disclosed by the invention, the problem of polarity inversion caused by the imaging angle under the acoustic vector dot product imaging condition can be eliminated, and the polarity consistency of the acoustic imaging event is improved, so that a guarantee is provided for the accuracy of geologic structure imaging in a complex environment.

The invention discloses an attenuation-considered scattered wave reverse time imaging seismic positioning method and system for a complex structure, and the method comprises the steps: building a frequency domain viscous sound wave equation, and representing a stratum absorption attenuation effect through a complex velocity model; introducing a contrast source based on a scattering theory, and separating a background wave field from a scattering wave field; inverse time continuation considering attenuation compensation is carried out, and energy focusing is realized through reverse wave field propagation and filtering processing; determining a focus position by applying imaging conditions; the invention specifically relates to an earthquake event positioning method based on a scattering theory, in particular to an inverse time continuation earthquake source positioning method under the condition of considering stratum heterogeneity and energy attenuation compensation, which can be applied to micro-earthquake monitoring related to industrial activities, hydrofracture effect evaluation and earthquake event positioning in complex geological structures. The technical problems of a traditional earthquake positioning method in a complex structure and an attenuation medium are effectively solved, and a new technical support is provided for underground space fine detection and engineering safety monitoring.