30 results about "Electromagnetic field computation" patented technology

A calculation method for a transformer winding considering a frequency-dependent loss, comprising: according to simulation requirements, defining key parameters calculated by using a finite-difference time-domain (FDTD) algorithm; constructing an equivalent flat wire model in an FDTD grid; calculating frequency-dependent internal impedance per unit length of a flat wire; and on the basis of a vector fitting method and a time-domain convolution calculation method, substituting the frequency-dependent internal impedance into a time-domain equation of the FDTD algorithm for updating and iterative solving, so as to obtain an electromagnetic field calculation result. In the present invention, on the basis of the vector fitting method and time-domain convolution calculation, the impact of the frequency-dependent characteristics of an electromagnetic field distributed in a conductor on an electromagnetic transient process is accurately considered during the FDTD time-domain solving, so that the calculation accuracy and efficiency of conventional FDTD algorithms and even conventional cross-scale modeling techniques can be significantly improved, thereby carrying out the targeted electromagnetic transient analysis on the reliability, safety, and predictability of transformers, and achieving the early detection of potential faults and defects, or formulating targeted maintenance plans and repair schemes.

The invention relates to the technical field of safe operation of power systems and motors, and particularly discloses a method for calculating a safe operation boundary of a high-inertia energy storage type phase modifier under a fault, and the method comprises the steps: building an electromagnetic field calculation model of a two-dimensional linear part and a three-dimensional end part region according to an electromagnetic design scheme of the high-inertia energy storage type phase modifier; establishing a frequency and voltage support excitation control system of the high-inertia energy storage type phase modifier, carrying out bidirectional dynamic coupling on the excitation control system and the electromagnetic field calculation model, and obtaining the frequency and voltage of a power grid through a phase-locked loop; determining the loss value of each structural member in the fault process through an electromagnetic field calculation model; according to the ventilation system structure of the high-inertia energy storage type phase modifier, a fluid and thermal coupling calculation model is established, and the loss value of each structural member is used as a heat source to be introduced into the fluid and thermal coupling calculation model; and determining the safe operation limit time of the high-inertia energy storage type phase modifier under the system frequency or voltage fault according to the maximum temperature rise allowed by each structural member.

The invention discloses an underwater wireless power transmission system parameter identification method based on machine learning, which comprises the following steps: constructing a data set through finite element simulation, and obtaining original input parameters including geometry, electromagnetism and position offset and corresponding key output parameters; feature engineering is executed, and derived features with physical significance are extracted; performing standardized preprocessing on the data; for each key output parameter, independently training an XGBoost regression model; carrying out five-fold cross validation on the training set by adopting a Bayesian optimization algorithm, and carrying out independent hyper-parameter optimization on each XGBoost model; and carrying out interpretability analysis on the trained agent model by utilizing SHAP analysis, quantifying the contribution degree of each input feature to a prediction result, and providing physical insight. According to the method, high-precision prediction of the electromagnetic parameters under the complex working condition is achieved, complex electromagnetic field calculation is avoided, the system design efficiency is remarkably improved, and the efficiency and interpretability of intelligent optimization design of the UWPT system are remarkably improved.

The invention belongs to the technical field of electromagnetic field calculation, and discloses a method and a system for calculating an electromagnetic scattering field of a moving target coated with a lossy dispersive medium. The method comprises the following steps: firstly, carrying out three-dimensional modeling on a target surface by adopting triangular surface elements to form a model file, and importing the model file into a main program to obtain geometric feature data of a target; secondly, carrying out relativistic coordinate transformation on the space-time component by utilizing Lorentz transformation, and mapping a dynamic problem to an inertial coordinate system synchronous with a target; then establishing an equivalent reflectivity model for the lossy dispersive medium coated area by adopting a transmission matrix method; then efficiently solving a transient scattering field in the motion coordinate system by adopting a time domain physical optical method; and finally, reconstructing a calculation result to a laboratory coordinate system through inverse Lorentz transformation, and outputting electromagnetic field distribution in a dynamic scene. Through the method provided by the invention, the electromagnetic scattering field of the moving target coated with the lossy dispersive medium can be quickly calculated.

The invention discloses a cargo in-vitro magnetic field calculation method based on boundary magnetic field numerical integration, which relates to the technical field of electromagnetic detection, and comprises the following steps: constructing a cargo numerical model in finite element electromagnetic field calculation software, and setting the size of the cargo numerical model; determining the position of an initial magnetic source based on the cargo numerical model, and setting the intensity of the initial magnetic source; respectively calculating magnetic field intensities at positions 2.1 m and 4.6 m away from the initial magnetic source intensity through finite element electromagnetic field calculation software to obtain spatial magnetic field data, further obtaining attenuation coefficients of transverse unit detection points of all boundary planes, obtaining an attenuation coefficient set, and performing spatial interpolation and translation processing; coupling each actually measured magnetic field data acquired by the array sensor with attenuation coefficients at corresponding positions, and respectively solving magnetic field intensities at positions 2.1 m and 4.6 m away from the surface of a measured object; high-precision and high-efficiency calculation of the external magnetic field of the cargo is realized, and the rapid and lossless requirements of air transportation safety detection are met.

The invention discloses a Python-based power transmission line electromagnetic field finite element automatic modeling and analysis method in the field of electromagnetic field finite element simulation and power system analysis. A Python script language is combined with a finite element calculation engine, information is analyzed through programming, and the precise spatial position of each hanging point of the power transmission line in a global coordinate system is obtained through automatic conversion of coordinates; based on the obtained parameters, script programming is used for completing three-dimensional geometric modeling of the wire, and then automatic modeling and parameterized definition are achieved; then, script programming is used for achieving calculation domain setting, boundary condition setting, voltage and current giving, phase sequence setting and other setting of a line section to be calculated, and three-dimensional finite element simulation calculation of an alternating current electric field and a magnetic field of the designated line section is completed; and performing multi-dimensional visual display on the electric field and magnetic induction intensity in combination with a Python visual library. According to the system, automatic processing from GIM data to an electromagnetic field calculation result is achieved, electromagnetic field calculation of complex lines such as mixed voltage and cross crossing can be completed, modeling efficiency and calculation precision are remarkably improved, and an efficient simulation means is provided for electromagnetic environment evaluation and equipment optimization arrangement of the power transmission line.

The application provides a method for controlling V-shaped segregation of square billet by using a traveling wave linear electromagnetic stirrer, and relates to the technical field of steelmaking-continuous casting. The method sets a traveling wave linear electromagnetic stirrer at the solidification end of a square billet continuous casting machine; then a numerical simulation prediction model of the end linear electromagnetic stirring and continuous casting billet solidification growth is constructed by an electromagnetic field calculation model of the end traveling wave linear electromagnetic stirrer and a continuous casting multiphase solidification physical model; the strength of the end linear electromagnetic stirring is determined by solving the electromagnetic field calculation model; the time t0 value when the slip velocity of equiaxed crystals at the installation position of the electromagnetic stirrer at the solidification end is 0 m / s is obtained by solving the continuous casting multiphase solidification physical model, and then the distance between the center of the end electromagnetic stirrer and the meniscus is calculated, so that the installation position of the electromagnetic stirrer is determined; finally, the shell thickness of the solidification end casting billet is calculated, so as to guide the elimination of V-shaped segregation in the field production and maximize the improvement of the internal quality defects of the continuous casting billet.

The application belongs to the field of electromagnetic field calculation, and discloses a method for calculating electromagnetic scattering field of moving plasma target based on DGTD. The method firstly models the target to obtain a model file; then calculates the space and time components in the moving coordinate system by using Lorentz transformation formula, and introduces incident wave into the moving coordinate system; then iterates electromagnetic field in combination with the moving plasma model, calculates the near-field data under the moving coordinate system, and inversely transforms the near-field data by using Lorentz transformation to obtain the near-field data under the laboratory coordinate system, and extrapolates to obtain the laboratory coordinate system, Fourier transforms the time-domain incident electromagnetic field to obtain the frequency-domain value, and then solves to obtain the single-station radar scattering cross section (RCS) of the target under the laboratory coordinate system. The application can better fit complex models, is more flexible in the treatment of multi-scale problems, can effectively improve the numerical dispersion phenomenon, and can simulate moving targets with higher speed.

The invention provides a wafer detection device and a wafer optical detection method based on an RCWA improved algorithm, and belongs to the field of wafer quantity detection.The wafer detection device comprises an illumination system, a wafer moving table, a microscopic imaging system, an image processor and an imaging simulation system; the wafer optical detection method comprises the steps of wafer image acquisition, image preprocessing and acquisition of a to-be-detected image, light source modeling, material three-dimensional structure and optical parameter definition, RCWA calculation and near-field electric field distribution acquisition, far-field imaging calculation and reference image generation, image pair processing, difference image acquisition, threshold algorithm and convolution kernel processing, and the like. Acquiring defect position and signal intensity information, post-processing and generating a detection report. According to the RCWA improved algorithm based on the CPU coordinated allocation GPU computing cluster operation matrix index calculation, the overall wafer detection efficiency is improved, and the RCWA improved algorithm can be popularized and applied in the fields related to layer structure electromagnetic field calculation, such as wafer detection and photomask detection.

Methods, apparatus, devices, and systems for three-dimensional (3D) displaying objects are provided. In one aspect, a method includes obtaining data including respective primitive data for primitives corresponding to an object, determining an electromagnetic (EM) field contribution to each element of a display for each of the primitives by calculating an EM field propagation from the primitive to the element, generating a sum of the EM field contributions from the primitives for each of the elements, transmitting to each of the elements a respective control signal for modulating at least one property of the element based on the sum of the EM field contributions, and transmitting a timing control signal to an illuminator to activate the illuminator to illuminate light on the display, such that the light is caused by the modulated elements of the display to form a volumetric light field corresponding to the object.

Methods, apparatus, devices, and systems for displaying objects in three dimensions (3D) are provided. In one aspect, a method includes: obtaining data including corresponding primitive data of primitives corresponding to the object; determining the electromagnetic field contribution of the primitives to the display elements by calculating the electromagnetic field propagation from each primitive to each display element of the display screen; generating a sum of electromagnetic field contributions of a plurality of the primitives to each display element; sending a corresponding control signal to each display element to modulate at least one characteristic of the display element based on the sum of electromagnetic field contributions; and sending a timing control signal to an illuminator to activate the illuminator thereby illuminating light onto the display screen, such that the modulated display elements of the display screen cause the light to form a volumetric light field corresponding to the object.

The application provides a method and system for adaptively and optimally selecting background field conductivity in electromagnetic field forward modeling of a horizontal well, wherein the method comprises the following steps: extracting characteristic parameters from a full-tensor anisotropic conductivity tensor of a target formation, and constructing a candidate background conductivity parameter set; calculating a difference spectral domain field corresponding to the candidate background conductivity parameters; performing convergence quantitative analysis on the difference spectral domain field, comprehensively evaluating and ranking each candidate background conductivity parameter based on a convergence evaluation index, and determining an optimal background conductivity parameter; and performing a background field subtraction operation by using the optimal background conductivity parameter to obtain a final calculation result. The method and system for adaptively and optimally selecting background field conductivity in electromagnetic field forward modeling of a horizontal well can automatically identify the optimal background conductivity parameter in formations with different anisotropic types and intensities, improve the convergence of the difference spectral domain field, and improve the electromagnetic field calculation efficiency.

The invention discloses a full-wave electromagnetic field calculation method, and the method specifically comprises the steps: constructing a Maxwell rotation equation based on the propagation behavior of electromagnetic waves in a two-dimensional isotropic, non-dispersive and lossy medium; a Crank-Nicolson format which is unconditionally stable and has second-order precision is adopted to carry out discretization on the Maxwell rotation equation in time and space dimensions at the same time; substituting the discrete magnetic field component in the Maxwell rotation equation into the discrete electric field component in the Maxwell rotation equation to obtain a sparse linear equation; introducing a high-order error compensation item into the sparse linear equation to obtain a corrected equation; splitting the corrected equation to obtain two sub-equations; and simultaneously establishing the two sub-equations to obtain the field quantity of the electromagnetic field in the medium, thereby updating the electromagnetic field distribution in the medium in real time. The method provided by the invention can meet strict requirements of unconditional stability.

The application discloses a kind of multi-physical field coupling power equipment real-time simulation method, device, equipment and storage medium, for solving the technical problems that significant deviation exists between the simulation results of existing simulation system and the actual operating state of equipment.The present application comprises: when receiving operation starting signal, in each simulation step, the resistivity correction coefficient of last thermal field calculation is obtained to carry out electromagnetic field calculation, and electromagnetic simulation data is generated;Electromagnetic simulation data includes electromagnetic force distribution data and loss distribution data;When the counter value of global time synchronization scheduler reaches the first preset value, the force field calculation is carried out using electromagnetic force distribution data, and the mechanical simulation data of iron core structure is generated;When the counter value reaches the second preset value, the thermal field calculation is carried out using the loss distribution data of second preset value simulation step, and thermal simulation data is generated;Output electromagnetic simulation data, mechanical simulation data and thermal simulation data.

The invention discloses a space electromagnetic field dynamic rapid measurement method and system, and the method comprises the steps: carrying out the sampling of a power transmission line electromagnetic field signal at three continuous equal-interval moments t1, t1 + t and t1 + 2t, and obtaining three sampling values y1, y2 and y3; the time span of the three sampling moments is smaller than a half period of the sine wave of the electromagnetic field signal so as to reduce the spatial distance between the sampling points; on the basis of a sine wave model of an electromagnetic field signal, an equation set is built by combining the three sampling values and the equal interval relation of the three sampling values, the equation set is simplified through a triangular identical equation, and the amplitude, the frequency and the phase of sine waves are obtained through solving. Through the technical means, sampling data of a sine wave complete period does not need to be collected, the space-time matching precision of an electromagnetic field calculation result and a measurement position is improved, and the space electromagnetic field detection efficiency and dynamic characteristics are improved.

The invention provides an electromagnetic field calculation method based on a regular port, computer equipment and a storage medium. The method comprises the following steps: acquiring port geometric parameters, port impedance and input power; according to the geometric parameters, the port impedance and the input power, an electric field analytic expression of the port in a transverse electromagnetic wave mode is called, and an electric field distribution function of the port area is generated; projecting the electric field distribution function to an edge element vector basis function of the port, and constructing a linear equation set about an edge element expansion coefficient; solving the linear equation set to obtain an edge element expansion coefficient; constructing an excitation vector of an ultrafinite element equation according to the edge element expansion coefficient; and embedding the excitation vector into the ultralimit element equation, and solving the electromagnetic field of the three-dimensional calculation area. According to the scheme, the port control equation can be constructed by utilizing the analytical expression of the transverse electromagnetic wave mode electric field distribution of the regular port, and a complex generalized eigenvalue problem in a traditional method is converted into a solving problem of a linear equation set, so that the solving speed and the calculation precision are remarkably improved.

The invention discloses an electromagnetic reversing control method for an electromagnetic clutch, relates to the field of new energy power systems, and solves the technical problem that separation or interruption of different power sources cannot be realized due to the fact that a combination part is magnetized after an existing electromagnetic clutch is electrified for a long time. The method comprises the steps that when an electromagnetic reversing controller receives a combination instruction signal of a system controller, working parameters of an electromagnetic clutch are obtained, and the working parameters are analyzed through an electromagnetic field calculation algorithm so as to judge whether the electromagnetic clutch meets the reversing requirement or not. The invention further discloses an electromagnetic reversing control system of the electromagnetic clutch. The separation difficulty of the electromagnetic clutch can be effectively reduced.

This invention discloses a method for calculating and fitting the three-dimensional electromagnetic field of transmission lines by integrating tower parameters, including: 1) GIM data parsing; 2) coordinate unification transformation; 3) conductor modeling and equivalent processing: establishing the three-dimensional geometry of the conductor based on the catenary model and simplifying the split conductors accordingly; 4) finite element electromagnetic field calculation: establishing a three-dimensional model of the transmission line, setting boundary conditions and electrical excitations, and solving the electric and magnetic fields under tower- and towerless conditions; 5) establishing electric field proportionality: comparing the electric field results with and without towers to construct an electric field proportionality function; 6) fitting modeling: performing polynomial fitting on the proportionality function to establish an electric field mapping model; 7) height expansion and rapid prediction. This invention effectively reduces the computational load caused by detailed tower modeling while ensuring calculation accuracy, and is applicable to the rapid evaluation of the electromagnetic field of single-circuit, double-circuit, and complex structure transmission lines.

The application discloses a simulation method of GIS contact contact resistance, which comprises the following steps: firstly, calculating the equivalent radius of the contact resistance, and calculating the current flow area of the contact resistance according to the equivalent radius; keeping the current flow area unchanged, converting the shape of the contact resistance into a rectangular block, and establishing an equivalent contact resistance model for each contact finger in three-dimensional software; then, classifying and fusing the models of the whole contact finger area; in the electromagnetic field calculation, the size of the contact resistance and the size of the equivalent model are combined to convert the conductivity thereof, so as to simulate the working conditions of different contact resistances; in the temperature-fluid field coupling calculation, the size of the contact resistance and the conductivity are combined to calculate the thermal conductivity of the equivalent contact resistance, and the loss calculation result of the electromagnetic field is introduced into the temperature-fluid field, so that the accurate simulation of the contact resistance can be realized in simulation.

The invention provides an RCWA simulation calculation method of a target structure and scattering electromagnetic field acceleration calculation equipment, and belongs to the field of field calculation speed increase application. The RCWA simulation calculation method comprises the steps of calculating an index matrix corresponding to a transmission matrix, calculating the transmission matrix, calculating a scattering matrix corresponding to the transmission matrix by utilizing a layer scattering matrix conversion formula, calculating scattering matrixes of all layers, and obtaining a global scattering matrix by utilizing Redheffer star product operation connection; the scattering electromagnetic field accelerated calculation device comprises an information acquisition module, a GPU calculation cluster module, a simulation calculation module and a simulation application module. The simulation calculation module is used for solving near-field electromagnetic scattering characteristics of the periodic target structure based on an RCWA algorithm, simulating and calculating a far-field imaging process and outputting a simulation optical image; according to the RCWA algorithm based on matrix index calculation, the speed of multilayer structure field calculation is increased, and the RCWA algorithm is convenient to popularize and apply in the fields related to layer structure electromagnetic field calculation, such as wafer detection, photoetching processing, AR / VR display and the like.

The application discloses a kind of marine medium-voltage DC hybrid circuit breaker's solid seal pole temperature rise characteristic simulation method, comprising the following steps: (1) constructing the three-dimensional structure model of marine medium-voltage DC hybrid circuit breaker solid seal pole;(2) the equivalent model of contact resistance in three-dimensional structure model different contact interface is established, which is based on Holm formula, the size and conductivity of conductive bridge are determined by combining the parameters of brinell hardness and contact pressure of contact material, and the contact resistance of bolt connection is calculated according to pre-tightening force and tightening torque;(3) multi-physical field coupling simulation: electromagnetic-heat flow coupling method is used to establish external air domain and set pressure outlet to simulate natural convection, map the power loss distribution obtained by electromagnetic field calculation to heat flow field, and solve to obtain the steady-state temperature field of solid seal pole.The application constructs the equivalent model of contact interface in line with actual physical mechanism, and solves the error and cost problems caused by the simplification of contact resistance in traditional method or the dependence on experimental calibration.

The invention discloses a calculation system for conduction and scattering processes of electromagnetic waves in the abdomen, and relates to the technical field of electromagnetic simulation calculation. By accurately configuring electromagnetic-physical parameters, tumor parameters and PML boundary parameters, a simplified abdominal anatomy model is constructed, an electromagnetic calculation model is favorably adapted, and calculation efficiency and anatomy authenticity are both considered; uniform nodes are generated and breathing motion parameters are fused, so that the dynamic change of the abdomen of a human body in a real physiological state can be simulated; an adaptive kernel function is selected according to the characteristics of different tissue layers, and the pertinence and precision of electromagnetic field calculation are improved; an electromagnetic field calculation module is combined with a Maxwell equation and a central difference discretization method to accurately solve electromagnetic field distribution of each tissue layer of the abdomen; energy deposition of each tissue is quantified, a visual report is generated, and a safety warning is triggered in time; and an EKF dynamic parameter correction module is combined with Kalman filtering to correct node characteristics in real time, so that the accuracy and dynamic adaptability of abdominal anatomy simplified model parameters are improved.

The application provides an electromagnetic field calculation method, device and equipment based on a physically constrained neural network. Applied to the field of electromagnetic field calculation, the method comprises: a distribution range, physical parameters and a background signal source of a model of an electromagnetic field to be calculated can be acquired; a model constraint condition and a physical constraint condition are determined according to the distribution range, the physical parameters and the background signal source; sampling data of the model are input into a preset neural network model for calculating an electromagnetic field to obtain an electromagnetic field of the model. The method of the application constrains the neural network through the physical law of electromagnetic field change, and only the model range of the electromagnetic field to be calculated needs to be determined when the electromagnetic field is calculated, without a large amount of known data as data driving, so that the calculation efficiency of the electromagnetic field is improved.

The application provides a rule port-based electromagnetic field calculation method, a computer device and a storage medium, and the method comprises the following steps: acquiring port geometric parameters, port impedance and input power; calling an electric field analytical expression of the port in a transverse electromagnetic wave mode according to the geometric parameters, the port impedance and the input power, and generating an electric field distribution function of a port area; projecting the electric field distribution function on an edge element vector base function of the port, and constructing a linear equation group about edge element expansion coefficients; solving the linear equation group, and obtaining the edge element expansion coefficients; constructing an excitation vector of a superfinite element equation according to the edge element expansion coefficients; embedding the excitation vector into the superfinite element equation, and solving a three-dimensional calculation area electromagnetic field. According to the scheme, the analytic expression of the electric field distribution of the transverse electromagnetic wave mode of the rule port is used to construct a port control equation, a complex generalized eigenvalue problem in a traditional method is converted into a solving problem of a linear equation group, and therefore the solving speed and the calculation accuracy are significantly improved.

The present invention discloses a method for accelerated solving of large sparse matrix, system and storage medium thereof, which falls into the technical field of electromagnetic field computation. In view of the problem that solving of the current large sparse matrix is slow and not accurate enough, the present invention provides a method for accelerated solving of large sparse matrix, comprising: restoring connection relationships between port nodes of an initial finite element matrix, and obtaining restored second-order finite element matrix; converting the second-order finite element matrix to an undirected graph; decomposing the undirected graph, and selecting optimal decomposition via an evaluation function; renumbering nodes of the second-order finite element matrix according to the renumbered nodes and generating a new final finite element matrix; and solving the final finite element matrix. In the present invention, by restoring the connection relationships of port nodes the subsequent solving accuracy is promised, by converting the matrix to the undirected graph and decomposing, the optimal decomposition is obtained and by going on with the subsequent operations as per the optimal decomposition, the solving of the matrix is accelerated.

This invention belongs to the field of electromagnetic field calculation, and specifically relates to a rapid solution method for electromagnetic field distribution under varying dielectric constants. The method solves for the physical field under initial boundary conditions using full-wave simulation. In subsequent iterative calculations, whenever the dielectric constant of the material changes, a modified calculation formula is used to continuously adjust the electromagnetic field distribution to obtain the corresponding distribution. This algorithm is particularly suitable for situations where the dielectric constant of a material gradually changes under the influence of external environmental factors. This invention solves the problem of the enormous computational burden caused by repetitive full-wave simulation calculations in traditional methods for constantly changing material physical properties and physical fields. By rapidly obtaining the real-time electromagnetic field distribution around the object, the electromagnetic field radiation and electromagnetic wave leakage of the system can be observed, thus resolving systemic electromagnetic compatibility issues.

The application discloses a kind of density stratified seawater in the measurement method and system of internal wave wake electromagnetic field, belong to underwater target detection technical field.A kind of density stratified seawater in the measurement method of internal wave wake electromagnetic field, comprising: obtaining the current speed and depth of underwater target, and the density, conductivity and dielectric constant of the sea area seawater where underwater target is located;The above parameters are brought into electromagnetic field calculation model to obtain the induced electromagnetic field of underwater target;Electromagnetic field calculation model is obtained based on the construction of the curl equation of magnetic field.Solved the current lack of direct simulation calculation model, resulting in difficult to realize accurate detection of underwater target by directly calculating internal wave wake electromagnetic field.The internal wave wake electromagnetic field of underwater target at different depth and speed is calculated quickly and accurately, and underwater target detection and identification are carried out accordingly.

The application belongs to the technical field of electromagnetic field calculation, and discloses a kind of coated with lossy dispersive medium moving target electromagnetic scattering field calculation method and system.The method of the application first adopts triangular facet to carry out three-dimensional modeling to target surface to form model file, then model file is imported into main program to obtain the geometric feature data of target;Secondly, the Lorentz transformation is used to carry out the relative coordinate conversion of space-time component, and the dynamic problem is mapped to the inertial coordinate system synchronized with the target;Then, the transmission matrix method is used to establish the equivalent reflectivity model of the region coated with lossy dispersive medium;Subsequently, the time-domain physical optics method is used to efficiently solve the transient scattering field in the moving coordinate system;Finally, the calculation results are reconstructed to the laboratory coordinate system through inverse Lorentz transformation, and the electromagnetic field distribution under dynamic scene is output.The method of the application can realize the fast calculation of electromagnetic scattering field of moving target coated with lossy dispersive medium.

The invention belongs to the field of electromagnetic field calculation, and discloses a DGTD-based electromagnetic scattering field calculation method for a moving plasma target. The method comprises the following steps: firstly, carrying out target modeling to obtain a model file; then calculating space and time components in the motion coordinate system by using a Lorentz transformation formula, and introducing incident waves into the motion coordinate system; performing electromagnetic field iteration in combination with a motion plasma model, calculating near-field data under a motion coordinate system, performing inverse Lorentz transformation on the near-field data to obtain near-field data under a laboratory coordinate system, performing extrapolation to obtain frequency domain values of time domain incident electromagnetic fields under the laboratory coordinate system, and performing Fourier transformation on the time domain incident electromagnetic fields to obtain the frequency domain values of the time domain incident electromagnetic fields; and then solving to obtain the single-station radar cross section RCS of the target under the laboratory coordinate system. According to the method, a complex model can be better fitted, processing on a multi-scale problem is more flexible, a numerical dispersion phenomenon can be effectively improved, and a moving target with a higher speed can be simulated.

The application discloses a method for analyzing characteristics of sea wave noise in layered seawater with conductivity, and belongs to the technical field of sea wave noise analysis. The method is used for solving the problem that the existing calculation of sea wave induced electromagnetic field often assumes that the seawater conductivity is uniformly distributed, and the marine environmental electromagnetic noise cannot be accurately analyzed. The method comprises the following steps: S1, a calculation model of sea wave induced electromagnetic field based on layered seawater with limited depth and conductivity is established; S2, the sea wave induced electromagnetic field is solved by using Maxwell differential equation and seawater wave equation conditions; S3, noise generated by sea wave motion cutting geomagnetic field is analyzed according to the solved sea wave induced electromagnetic field, and the spatial distribution of unit amplitude sea wave magnetic noise and electric noise is derived; and S4, sea wave electromagnetic noise power spectrum under different sea conditions is analyzed in combination with sea wave spectrum. The application considers the characteristic of uneven seawater conductivity, establishes a four-layer medium sea wave induced electromagnetic field calculation model, and analyzes the sea wave electromagnetic noise.