415 results about "Reflection coefficient" patented technology

The invention provides a composite board detection method and system, and relates to the technical field of board detection, and the method comprises the steps: carrying out the ultrasonic scanning of a composite board, dividing the composite board into a plurality of acoustic characteristic layers, building a sound wave propagation model based on a recursive transfer matrix method, and calculating the reflection coefficient and transmission coefficient of each layer interface. A deep learning algorithm is combined with physical constraints to dynamically correct acoustic parameters, the corrected parameters are substituted into a model reconstruction signal, and defects are accurately positioned. And performing grid division on the defect position to analyze stress field distribution, and determining a stress concentration position. And fine scanning is carried out on a stress concentration area by adjusting probe parameters, and high-resolution data is obtained to update defect distribution information. And finally, outputting detection data including defect positions, stress concentration distribution and hazard levels, and realizing accurate detection and evaluation of the defects of the composite board.

Disclosed are systems, apparatuses, processes, and computer-readable media for wireless communications. For example, an example of a process includes transmitting, to a reconfigurable intelligent surface (RIS), a plurality of reference signal beams in a plurality of directions. The process may further include receiving, from the RIS, a plurality of reflection reference signal beams in the plurality of directions based on a plurality of backtracking reflection coefficients. The process may include measuring a signal strength of each reflection reference signal beam in each direction of the plurality of directions for each backtracking reflection coefficient of the plurality of backtracking reflection coefficients. The process may further include determining, basing on measuring the signal strength, a selected beam direction from the plurality of directions and a selected backtracking reflection coefficient of the plurality of backtracking reflection coefficients.

The invention provides a crustal stress prediction method and device, electronic equipment and a storage medium, and relates to the technical field of seismic survey. The method comprises the following steps: obtaining observation seismic data of seismic wavelets in a strong VTI medium, and constructing a to-be-inverted parameter matrix based on a PP wave reflection coefficient corresponding to the strong VTI medium; constructing a posterior probability function obeyed by an inversion parameter matrix corresponding to the to-be-inverted parameter matrix based on a Bayesian inversion theory and observation seismic data, and determining a target functional based on a prior probability function and a likelihood function corresponding to the posterior probability function; determining medium density and each stiffness matrix coefficient based on an inversion parameter matrix solving result of the target functional, and determining a flexibility matrix of the strong VTI medium based on each stiffness matrix coefficient; and predicting the ground stress distribution of the target profile in the strong VTI medium based on the medium density and the positive strain matrix and the flexibility matrix corresponding to the strong VTI. Therefore, the crustal stress prediction accuracy under the strong VTI medium is improved.

The invention provides a photovoltaic power generation optimization method for a fishing-light complementary site and a related device. The method comprises the following steps: acquiring a photovoltaic panel sunlight angle, a water surface wind speed, a water surface wave height, a water depth, a photovoltaic panel core parameter, a reflector parameter and double-measuring-point actually-measured light intensity data; determining the initial receiving radiation quantity of the photovoltaic panel according to the sunlight angle of the photovoltaic panel, the core parameters of the photovoltaic panel, the parameters of the reflector and the actually measured light intensity data of the double measuring points; according to the water surface wind speed, the water surface wave height, the water depth, the double-measuring-point actually-measured light intensity data and the reflector parameters, the water surface correction reflection coefficient is determined; correcting the initial received radiation quantity of the photovoltaic panel by adopting the water surface correction reflection coefficient to obtain the actual received radiation quantity of the photovoltaic panel; and according to the actually received radiation quantity of the photovoltaic panel, the inclination angle of the photovoltaic panel is adjusted, and then the photovoltaic power generation process of the fishing-light complementary site is optimized. Excessive concentration of local radiation quantity caused by secondary reflection of sunlight through a water surface-reflector can be avoided, and generation of hot spots on the photovoltaic panel is inhibited.

A method includes defining a design domain for a meta-element configured to be attached to an edge of thin wall structure with an arbitrary boundary condition, and executing a topological optimization process on the design domain and providing a topology optimized shape for the meta-element. The topological optimization process includes an objective function that minimizes a reflection coefficient of flexural waves in the audible frequency range propagating towards and impinging the meta-element.

The invention relates to a spherical wave oscillation-slow nuclear high-order decoupling method and device for physical property inversion, and belongs to the field of geophysical detection and acoustic detection. The method comprises the following steps: obtaining and inputting observation data, and initializing seabed elastic parameters; determining an integral interval according to the observation data, decomposing the integral interval into a plurality of sub-intervals, and setting a decoupling order; calculating an oscillation nuclear local integral matrix of each order corresponding to the observation data incident angle; calculating the angle deviation guiding quantity of each order of the slowly-varying kernel; calculating a reflection coefficient vector of each order of spherical wave; calculating a spherical wave reflection coefficient of high-order decoupling; and solving a subsequent inversion problem by using the obtained high-order decoupled spherical wave reflection coefficient. According to the method, the calculation efficiency of the seabed spherical wave reflection coefficient in the inversion process is effectively improved; the decoupling order is improved, the calculation precision is improved, or the number of the subintervals can be reduced by improving the decoupling order under the condition that the calculation precision is certain.

The invention relates to a seabed elastic parameter inversion method, system and device under an earthquake spherical reflection wave oscillation-gradual change nuclear decoupling framework, and belongs to the field of geophysical detection and acoustic detection. The method comprises the following steps: (1) inputting observation data and initializing seabed elastic parameters; (2) determining an integral interval and decomposing the integral interval into a plurality of sub-intervals; (3) calculating an oscillation nuclear local integral matrix corresponding to the incident angle of the observation data; (4) calculating a slowly-varying kernel local mean vector; (5) calculating a spherical wave reflection coefficient of oscillation-gradual change kernel decoupling; and (6) constructing a target function by using the decoupled spherical wave reflection coefficient, and solving the target function. In the objective function solving process, only the steps (4) and (5) need to be repeatedly executed after the seabed elastic parameters are updated, the oscillation nuclear local integral matrix in the step (3) does not need to be repeatedly calculated, redundant calculation about oscillation nuclear integration is avoided, and the calculation efficiency is improved.

The invention discloses a design method of a double-layer metasurface wave absorber, the double-layer metasurface wave absorber comprises a pixelated unit located on the upper layer and a regular topological pattern structure located on the lower layer, and the method comprises the following steps: dispersing a resistive film-air structure of the pattern layer of the pixelated unit into a pixelated structure image, and representing the pixelated structure image by using a 0-1 matrix; generating a plurality of groups of 0-1 matrixes, constructing a pixelated unit, and obtaining a reflection coefficient curve; combining the target reflection coefficient curve and multiple groups of random noise into combined vectors, inputting the combined vectors into a generator, generating multiple target pixelated structure images, and obtaining multiple target pixelated units; determining design parameters of a resonance pattern layer, inputting the target reflection coefficient curve into a DNN neural network, outputting target design parameters, and obtaining a target regular topological pattern structure; and combining the target pixelated unit with the target regular topological pattern structure to obtain the target double-layer metasurface wave absorber. According to the method, rapid design of the double-layer metasurface wave absorber can be completed.

The invention relates to the technical field of cable line operation and maintenance, in particular to a cable fault accurate positioning method and system based on electromagnetic time reversal correction. And in combination with a reflection coefficient correction and local energy extraction method in a time inversion process, the problems that the fault traveling wave signal is attenuated and distorted under strong noise and high transition resistance, and the EMTR positioning effect is influenced by fault resistance are solved. Constructing a multi-scale evaluation system fusing time domain, frequency domain and wavelet domain features, and screening an optimal modal component; and constructing an actual fault resistor in a reverse phase of the EMTR to correct a reflection coefficient, and providing a criterion for positioning by using local energy at a first traveling wave to realize accurate positioning of a cable fault. According to the method, the ranging error can be effectively reduced under the conditions of high transition resistance, low signal-to-noise ratio and unknown fault resistance, and the robustness and engineering applicability of cable fault diagnosis are improved.

The invention discloses a cable hidden damage fault positioning method and device and a computer program product, and the method comprises the steps: S1, obtaining the structural parameters of a detected cable, building a one-dimensional distribution parameter transmission line model according to the structural parameters, and dividing the whole cable into a plurality of normal sub-segments and defect sub-segments; s2, calculating a reflection coefficient spectrum of a cable head end reflection coefficient along with frequency change according to distribution parameter change caused by moisture intrusion; s3, performing spectrum analysis on the reflection coefficient spectrum by adopting windowing Fourier transform, inhibiting spectrum leakage and extracting a periodic component of the spectrum leakage; and S4, determining a defect position according to the extracted periodic component frequency in combination with the propagation speed of the electromagnetic wave in the cable. According to the method, the positioning precision of the hidden damage fault of the cable can be improved, the test frequency requirement is reduced, and the diagnosis robustness in different load environments is enhanced.

The invention discloses a double-probe film thickness and defect collaborative decoupling method. The method comprises the steps that microwave reflection signals of a thermal barrier coating are synchronously collected through a coaxial resonance probe and a CSRR resonance ring probe; the microwave reflection signal comprises reflection coefficient amplitude, reflection coefficient phase and resonant frequency; constructing a frequency deviation model based on the microwave reflection signal; training the dual-channel deep learning network based on the frequency deviation model to obtain a trained dual-channel deep learning network; and obtaining film thickness information and a defect positioning result based on the trained dual-channel deep learning network. According to the method, collaborative decoupling of the film thickness and the defect signal is achieved through a physical-data fusion method, effective decoupling and independent recognition of the coating film thickness change and the defect response signal are achieved, and the resolution ratio, the accuracy rate and the practicability of a detection system are improved.

The invention discloses a three-dimensional ground penetrating radar detection method, system and equipment for road roadbed diseases and a medium, and relates to the technical field of road engineering detection. Controlling a high-frequency antenna and a low-frequency antenna to emit electromagnetic waves to a road roadbed based on the movement of the detection vehicle so as to receive reflected high-frequency data and low-frequency data; processing the high-frequency data and the low-frequency data based on the positioning attitude data to obtain processed high-frequency data and processed low-frequency data; processing and fusing the processed high-frequency data and the processed low-frequency data to obtain a full-band reflection coefficient sequence; calculating the full-band reflection coefficient sequence to obtain broadband geological radar data; inputting broadband geological radar data into the convolutional neural network model to obtain a disease type and a disease semantic segmentation map; and generating a three-dimensional visual model of the roadbed disease based on the disease semantic segmentation map, and outputting maintenance suggestion data matched with the disease type. By implementing the technical scheme, the accuracy of deep hidden disease recognition is improved.

The present application relates to the flexible DC power grid single-ended line protection method based on time domain voltage traveling wave, according to the difference of voltage traveling wave reflection coefficient under the positive and negative direction short circuit fault or lightning disturbance, the direction criterion is constituted, and the protection misoperation under the reverse direction fault or lightning is avoided, second, the function model that the first traveling wave of protection fault voltage satisfies under the short circuit fault in the area and the positive direction non-area short circuit fault is analyzed by using voltage traveling wave transfer function, according to the different matching degree between the first traveling wave of fault and the reference function model, the complete line single-ended protection method is formed by combining the starting criterion and the pole selection criterion.The present application builds the flexible DC power grid model on the PSCAD platform to verify the protection performance, and a large number of simulation results show that the proposed protection has high reliability and can tolerate 500Ω transition resistance.

The invention provides a projection lamp shadow effect intelligent adjustment method based on artificial intelligence, and the method comprises the steps: obtaining the material type and reflection coefficient of the wall surface of each region of an exhibition space through a pre-established wall surface material database, carrying out the classification processing according to the reflection characteristics of different materials, and obtaining a material reflection distribution diagram; acquiring light intensity distribution in the space based on stray light distribution characteristics, performing gridding decomposition on the light intensity distribution, and obtaining light intensity and light field distribution uniformity of each grid area through numerical integration; according to the adjusted projection angle and light source position, generating a control parameter for the projection equipment, adjusting the output intensity and direction of the projection light source, and obtaining the light distribution intensity after the control parameter of the projection equipment is adjusted; and if the contrast ratio and the color deviation value of the detail area do not meet the preset standard, optimizing the light source control parameters through an ambient light compensation mechanism in combination with the accumulated intensity data of the space corner to obtain a light compensation result.

Examples are directed toward a system and method relating to extracting a complex permittivity of a material. For example, a system includes a Vector Network Analyzer (VNA) that performs a first reflection measurement for a front interface of the material, and obtains first time-domain data by applying an inverse fast Fourier transform (IFFT) to the first reflection measurement. The VNA performs a second reflection measurement for a back interface of a material, and obtains second time-domain data by applying the IFFT to the second reflection measurement. The system performs a set of two measurements, including the measurements set forth above at the interfaces with the material, and similar measurements at the locations of the interfaces but without the material (e.g., empty measurements). A processor determines a real part of a refractive index of the material based on velocity, and determines an imaginary part of the refractive index of the material based on energy loss.

The invention discloses a grounding grid corrosion and soil defect diagnosis method based on impact square wave modulation, and relates to the technical field of electric power system intelligent operation and maintenance and equipment state monitoring. A broadband impact square wave modulated by a Gaussian window is generated and injected into a grounding down lead, and electromagnetic response of an underground conductor and soil is stimulated; the method comprises the following steps: acquiring an electric field signal by using an earth surface distributed sensor array, and extracting reflection time delay and frequency domain characteristics in combination with short-time Fourier transform STFT; reconstructing a time domain dielectric constant through reflection coefficient inversion and inverse Fourier transform, and decoupling metal corrosion and soil environment abnormity; based on a multi-parameter fusion criterion, accurate positioning and classification of defects such as fracture, corrosion, water accumulation and cavities are realized, and a resistivity-dielectric property dual-channel thermodynamic diagram is generated. According to the method, excavation is not needed, live detection can be achieved, the advantages of high resolution, non-destructiveness and visualization are achieved, and the accuracy and the intelligent level of grounding grid state diagnosis are remarkably improved.

The invention provides a microwave detection method and device for PE pipe hot-melting weld defects, and the method comprises the following steps: 1) taking a hot-melting weld of a PE pipe and a base material near the weld as detection objects, and carrying out axial and circumferential microwave scanning to obtain a reflection coefficient of each position point; 2) carrying out two-dimensional space Fourier transform on the reflection coefficient of each position point; 3) carrying out phase correction on the converted data in the depth direction; 4) carrying out two-dimensional space inverse Fourier transform on the corrected data to obtain a reflection coefficient of the target; 5, image reconstruction is carried out on the reflection coefficient of the target, and information of the defects in the PE pipe hot-melt welding seam is obtained.According to the scheme, the method has the advantages that the defects can be detected, the defect positions can be determined, and conclusion obtaining does not excessively depend on personnel skills.

A high-frequency power supply system according to the present disclosure includes a first power supply, a second power supply, and a first matcher. The first power supply performs frequency modulation control in a second power supply ON period and performs frequency offset control to output a forward wave voltage VF3 having a fundamental frequency F3 obtained by adding an offset frequency to a fundamental frequency F1 in a second power supply OFF period. An optimum value of an initial phase α of a modulation signal is searched for, and an offset frequency Fos at which a difference between a reflection coefficient ρ11 or load-side impedance Z11 corresponding to a center of a locus and a reflection coefficient ρ12 or load-side impedance Z12 is minimum is searched for, and the fundamental frequency F3 in the second power supply OFF period is set.

The invention relates to a river channel sand body random model generation method and device based on hidden Markov model data filling, a medium and equipment. The method comprises the steps that logging data of a target area are collected and arranged; dividing logging data according to a logging gas-bearing interpretation conclusion, and carrying out analytical statistics on the velocity and density of longitudinal and transverse waves in the logging data; initializing an initial state probability, a state transition matrix, and a mean value and a covariance of Gaussian distribution in the hidden Markov model; inputting a three-dimensional observation vector composed of the velocity and density of the longitudinal and transverse waves into the initialized hidden Markov model for iterative training; performing down-sampling on the lithology data, then constructing a state transition probability matrix, and further constructing a lithology sequence conforming to a geological law through simulation; according to the lithologic sequence, calling a hidden Markov model to generate longitudinal wave velocity, transverse wave velocity and density corresponding to the lithologic sequence; and calculating a reflection coefficient of the synthetic stratum, setting a Ricker wavelet dominant frequency, and obtaining synthetic seismic response data through convolution.

The invention discloses a mechanical non-resonant one-bit phase electromagnetic reflection metasurface unit, and belongs to the field of artificial electromagnetic materials. The unit comprises a non-resonant electromagnetic structure and a mechanical driving device. The non-resonant electromagnetic structure comprises a dielectric layer, an air layer and an adjustable metal backboard from top to bottom; the mechanical driving device adopts a bidirectional self-holding electromagnet, a screw rod of the bidirectional self-holding electromagnet is connected with the metal back plate, the back plate is driven to be switched between two preset positions through forward / reverse pulse current, the thickness of an air layer is accurately adjusted, and therefore one-bit dynamic switching of a reflection phase between 0 degree and 180 degrees is achieved through propagation phase accumulation. In the 5G millimeter wave frequency band of 20 GHz to 29.5 GHz, the reflection coefficients of the two states are both larger than 0.99, the phase difference is stabilized within 180 degrees + / -20 degrees, and good robustness is achieved for mechanical displacement deviation. The unit has the advantages of zero static energy consumption, low insertion loss, wide bandwidth, simple structure and simple control, and is suitable for a low-power-consumption intelligent reflecting surface and a dynamic beam forming system.

A standing wave radar includes: a transmitter to set a frequency of a transmission signal to frequencies, and output the transmission signal taking the respective frequencies in a time-division manner; a receiver to receive a reflected signal taking the frequencies in a time-division manner, the reflected signal being the transmission signal reflected by an object; and a processor to obtain reflection coefficients of the frequencies by obtaining each reflection coefficient of the transmission signal and the reflected signal taking a same frequency, for the transmission signal and the reflected signal taking the frequencies, and to execute a first inverse Fourier transform process of calculating a first distance spectrum for the object by an inverse Fourier transform on the reflection coefficients, and a first distance measurement process of determining presence of the object and calculating a distance to the object, based on the first distance spectrum.

The invention discloses a plastic pipe wall thickness detection method based on a millimeter wave technology, and relates to the technical field of millimeter waves, and the method comprises the steps: S1, transmitting an original signal to a target plastic pipe, and calculating the overall dielectric constant of the target plastic pipe; s2, attenuating a slope value, and calculating a loss tangent value and an attenuation coefficient; s3, constructing a time domain matched filter to generate a corrected reflection signal and an original time delay set; and S4, calculating an optimal time delay value based on the outer wall peak and the optimal peak, and calculating a real thickness value by using the optimal time delay value and the dielectric constant. Compared with the prior art, by means of attenuation coefficient calculation and time domain matched filter compensation and introduction of reflection coefficient inversion dielectric constant and loss angle tangent value estimation, the detection capability of inner wall weak reflection signals is improved; the method has the advantages that the probability of inner wall recognition failure or misrecognition is remarkably reduced, and the thickness calculation precision is remarkably improved.

The present invention relates to a method (100) for dielectric spectroscopy of a material or a tissue under test, comprising the following steps: measuring (110) the reflection coefficient (11) signal as a function of the frequency of said material or tissue under test, by a vector network analyzer (3), wherein a single applicator (5) is in contact with said material or a tissue under test and wherein the applicator (5) is operatively connected to the vector network analyzer (3); multiplying (120) the reflection coefficient (11) signal with the frequency behavior of an ultra-wide band (UWB) signal as a synthetic applicator excitation; converting (130) the signal of the previous step into the time domain by an Inverse Fourier Transform (IFT); suppressing (140) part of the converted signal of the converting step (130), according to the applicator (5) geometry; converting back (150) the signal of the suppressing step (140) to the frequency domain; and extracting (160) from the frequency signal converted the dielectric properties (162) and / or estimating (170) the dimension of the material or a tissue under test and / or of an ablated area of the material or a tissue under test thereof. The present invention also relates to an apparatus for dielectric spectroscopy (1).

The invention discloses a symbiotic radio system design and optimization method based on multiple active intelligent reflection surfaces. According to the method, high-efficiency backscatter communication is realized while the performance of the main transmission system is enhanced by using the intelligent reflection surface. A plurality of active intelligent reflecting surfaces are configured in the system, the main transmission performance is enhanced, and meanwhile, the active intelligent reflecting surfaces serve as backscattering equipment in turn, and transmission of secondary information is achieved by conducting scattering modulation on incident main signals. The method aims at maximizing the main transmission rate of the system, and jointly optimizes the base station sending power, the active beam forming vector and the reflection coefficient of the intelligent reflection surface. An original non-convex optimization problem is decomposed into a plurality of sub-problems, semi-definite relaxation, continuous convex approximation and other methods are adopted for conversion, and finally an optimal solution is obtained through iterative solution. Compared with a scheme based on a passive intelligent reflection surface and an active intelligent reflection surface scheme based on phase random, a higher main transmission rate can be realized under the condition of ensuring the same secondary symbol signal to interference plus noise ratio.

The application provides a method for calculating interface polarization charge and current distribution based on reflection coefficient, and relates to the technical field of computational electromagnetics. The method comprises the following steps: establishing a reflection coefficient-dielectric parameter mapping, directly correlating the reflection characteristics of electromagnetic waves with the intrinsic parameters of the medium through a reflection coefficient formula, and laying a physical foundation for polarization analysis; interface electromagnetic field reconstruction, using boundary conditions and constitutive relations to determine the electric field distribution on both sides of the interface and the corresponding polarization intensity. The distribution rule of the electromagnetic field in the medium is determined, the macroscopic electric field is converted into the spatial description of the polarization intensity, and an intermediate variable is provided for charge and current calculation; polarization dynamic response quantification, through the spatial and temporal derivatives of the polarization intensity, the interface polarization charge density and the polarization current density are derived. The theoretical model is converted into actual physical quantities, and the dynamic response mechanism of charges and currents when electromagnetic waves interact with the medium is revealed.

The present application relates to a kind of seismic wave impedance diffusion inversion method and device, its essence is a kind of from well site to surrounding diffusion layered structure and attribute inversion method.Core is to use well logging curve to carry out layering etc., then carry out well position inversion, simultaneously, to make the result obtained by well logging interpretation and actual seismic record difference minimum, need to be appropriately disturbed by the square wave type calibration layering curve obtained from well logging interpretation, generate hundreds of reflection coefficient curves, to generate synthetic seismic record, find the synthetic record with actual seismic record difference minimum, the horizon etc. corresponding to this best synthetic record is regarded as the best seed solution and diffuses to all around, during diffusion process, by adding time window or horizon to constrain vertical propagation interval, to obtain the inversion optimum value of entire data set, specific flow as shown in Figure 1.The present application improves the precision of thin layer boundary delineation, and has higher potential for thin layer resolution.

Quarter-wavelength switchable directional coupler architectures and methods that that use intermediate terminated states during directional mode-switching events to prevent generation of reflection coefficients that cause spur generation. A first embodiment of the invention utilizes existing circuitry within a quarter-wavelength switchable directional coupler but alters the conventional mode-switching sequence by adding new stage sequences to effectuate intermediate terminated states to mitigate or prevent spurs. A second embodiment of the invention modifies existing circuitry within a quarter-wavelength switchable directional coupler by adding a cross-coupled intermediate-stage termination circuit, and alters the conventional mode-switching sequence by adding new stage sequences to effectuate intermediate terminated states to mitigate or prevent spurs. A third embodiment of the invention also modifies existing circuitry within a quarter-wavelength switchable directional coupler by adding dual independent intermediate-stage termination circuits, and alters the conventional mode-switching sequence by adding new stage sequences to effectuate intermediate terminated states to mitigate or prevent spurs.

The invention relates to a low-voltage cable fault diagnosis positioning method and device based on stepping frequency wave reflection. The low-voltage cable fault diagnosis and positioning method based on stepping frequency wave reflection comprises the following steps: inputting a stepping frequency signal to a first end of a cable, and receiving a reflection signal of the stepping frequency signal; establishing an equivalent parameter model of the to-be-detected cable; calculating a reflection coefficient L of the first end according to the equivalent parameter model and the reflection signal; judging whether the cable has a fault according to the L; if gamma is equal to 0, the cable is healthy, and if gamma is not equal to 0, the cable has a fault; and determining the fault distance according to the time difference between the step frequency signal and the reflection signal. By injecting the detection signal into the to-be-detected cable and extracting the reflected wave, local insulation damage of the low-voltage cable can be effectively detected, potential fault points can be found in time, accidental power failure and accidents caused by insulation damage can be prevented and reduced, and the safety of a power grid is improved.

The invention discloses a cable joint damp degree assessment method and device and a storage medium. The method comprises the steps of obtaining a target reflection coefficient spectrum function corresponding to a target cable; b envelope peaks corresponding to the target reflection coefficient spectrum function are determined; b cable joints corresponding to the b envelope peaks in the a cable joints are determined; converting the target reflection coefficient spectrum function from a frequency domain to a time domain by adopting a preset time-frequency domain conversion algorithm to obtain a target time domain function; determining pulse peak pairs in the target time domain function to obtain b pulse peak pairs; and according to the b envelope peaks and the b pulse peak pairs, determining the damp degrees corresponding to the b cable joints to obtain b damp degrees. According to the embodiment of the invention, the detection precision of the damp degree is improved.