32 results about "Total field" patented technology

The embodiment of the invention provides an aviation gravity and magnetic vector dynamic measurement method based on multi-source data synchronous fusion, and relates to the technical field of data acquisition, after sensor array data on a driving flight platform is acquired, a specific force measurement value, a carrier pitch angle, a carrier roll angle and a carrier motion parameter are calculated and output; calculating three output gravity disturbance components by adopting carrier motion parameters and specific force measurement values; fusing total field data of the optical pumping magnetometer to carry out magnetic vector calculation on three-component data of the fluxgate and outputting geomagnetic total elements; and taking a carrier pitch angle, a carrier roll angle, a carrier position, a carrier speed and a carrier course angle as carrier pose data, combining the geomagnetic total elements and the carrier pose data, and outputting a dynamic measurement result of the gravity-magnetic vector field. The problems that in the prior art, gravity measurement and magnetic measurement are separated, equipment redundancy is low in efficiency, collection time is asynchronous, and data precision is reduced are solved. The effect of high-precision, high-dynamic and high-efficiency synchronous acquisition of the gravity and magnetic vector data under the single platform is achieved.

This invention provides a method and system for three-dimensional high-frequency controllable source electromagnetic numerical simulation with dual-source excitation. The method constructs a single-source electromagnetic field grid model and a three-dimensional spatial domain total field equation, converting it into a quadratic field control equation by separating the primary and secondary fields. Fourier transform is used to transform the equations to the wavenumber domain, and shape function interpolation is performed iteratively to obtain the wavenumber domain numerical solution. A single-source forward excitation solution is obtained through inverse Fourier transform. A single-source reverse excitation solution is obtained by reversing the current direction. Finally, the forward and reverse solutions are vector-superimposed to obtain the dual-source excitation simulation result. This invention solves the technical problems of existing technologies, such as simulation distortion caused by neglecting displacement current in the 100kHz-10MHz frequency band, numerical calculation interference from field source singularities, and low spatial resolution of complex underground anomalies under single-source excitation. By simulating gradient field response characteristics through dual-source reverse superposition, the sensitivity and exploration resolution of underground target boundaries are significantly improved.

The invention discloses a method for calculating a quantitative magnetic susceptibility image through total field inversion based on a Green function. The method is used for separating a background magnetic field and reconstructing a whole-brain quantitative magnetic susceptibility image in magnetic resonance imaging. According to the boundary element method full-field inversion method, filtering and regularization processing on tissue magnetic susceptibility are prevented from being additionally introduced when background field interference is removed, the background field can be effectively separated, a whole-brain quantitative magnetic susceptibility image can be reconstructed, the boundary erosion phenomenon cannot occur, and the boundary element method full-field inversion method particularly shows excellent performance in a cortex area. According to the method, a fast multipole method is adopted to efficiently process storage and calculation of a dense matrix generated by a boundary integral equation.

The embodiment of the application provides a dynamic measurement method for aviation gravity and magnetic vector based on multi-source data synchronous fusion, relates to the technical field of data acquisition, and outputs the specific force measurement value, the carrier pitch angle, the carrier roll angle and the carrier motion parameter after driving the flight platform to collect the sensing array data; adopts the carrier motion parameter and the specific force measurement value to output the gravity disturbance three components; fuses the total field data of the optical pumping magnetometer to perform the magnetic vector calculation and output of the geomagnetic full element of the flux gate three component data; takes the carrier pitch angle, the carrier roll angle, the carrier position, the carrier speed and the carrier heading angle as the carrier pose data, combines the geomagnetic full element and the carrier pose data, and outputs the dynamic measurement result of the gravity and magnetic vector field. The problems that the gravity and magnetic force measurement are separated in the prior art, the equipment is redundant and inefficient, the acquisition time is asynchronous, and the data precision is reduced are solved. The effect of high-precision, high-dynamic and high-efficiency synchronous acquisition of the gravity and magnetic vector data under a single platform is achieved.

The invention discloses an optical lens and a preparation method and application thereof. The optical lens comprises a transparent substrate, a micro-lens array located on the first surface and a super-lens array located on the second surface. The transparent substrate comprises a first surface and a second surface which are oppositely arranged. The microlens array comprises a plurality of microlenses arranged at intervals, each microlens forms a sub-view field, and the plurality of sub-view fields jointly form a total view field. The super lens array comprises super lenses in one-to-one correspondence with the micro lenses, and the super lenses compensate the wavefront difference of the micro lenses through phase distribution. The large field of view is decomposed into a plurality of small sub-fields of view through the micro-lens array, gradient phase distribution is realized through the nano-structure of the super-lens, the residual wavefront difference of the micro-lens is compensated, the aberration generated by the micro-lens is accurately corrected, and after light rays finally reach the imaging sensor array, large FOV seamless imaging can be realized in combination with an image fusion algorithm.

The application provides a plate thinning defect shape finding method based on a few-frequency reflected ultrasonic guided wave, and comprises the following steps: S1: mode separation is performed on a total field of a reflected wave to obtain a reflection coefficient of a required guided wave mode; S2: a Green function in a defect-free plate is solved to obtain an approximate solution of a far field; S3: a reconstruction equation of a plate defect is established and preliminary reconstruction is performed; and S4: accurate determination of a plate defect shape is performed. The method is used for rapid quantitative detection of a plate structure thinning defect, and based on reflection data of the ultrasonic guided wave at a few frequency points, the shape of the defect can be found, the defect shape is accurately determined, a better detection effect is realized at a relatively low cost, and thus a convenient and reliable detection technology is provided for engineering detection.

The invention relates to an underground target detection method based on an improved variational Born iteration method. The method comprises the following steps: S1, obtaining an actual scattering magnetic field at a receiving antenna; s2, solving an initial estimation value of the stratum contrast, and taking the initial estimation value as a current estimation value; s3, updating the total field of the stratum based on the current estimated value, and calculating an estimated scattering magnetic field at the receiving antenna; s4, obtaining a magnetic field difference value; s5, judging whether the relative residual error exceeds a threshold value or not, if so, taking the new stratum contrast estimation value as the current estimation value, and returning to S3; otherwise, obtaining a to-be-detected image based on the current estimated value, and executing S6; s6, obtaining an optimized to-be-detected image based on a self-adaptive Otsu method; and S7, inputting the optimized to-be-detected image into the underground target detection model to obtain a detection result. Compared with the prior art, the method has the advantages of target position determination accuracy, inversion target boundary sense and the like.

The application discloses a three-dimensional positioning method and device based on scalar magnetic gradient and related equipment, and the method comprises the following steps: acquiring two-dimensional scalar magnetic gradient data, the two-dimensional scalar magnetic gradient data is collected by two magnetic total field sensors which are vertically arranged in a detection area, and the record points of the two-dimensional scalar magnetic gradient data are uniformly distributed in the detection area; based on the two-dimensional scalar magnetic gradient data, two-dimensional scalar magnetic gradient energy level distribution data in a two-dimensional space formed by each group of unit orthogonal bases is acquired, the unit orthogonal bases are obtained by decomposing two-dimensional scalar magnetic gradient data generated by a magnetic dipole of a target body at an arbitrary height; based on the energy level distribution data, the horizontal positioning result and the vertical positioning result of the target body are determined. In the three-dimensional positioning process of the target body, the vector magnetic moment information of the target body is not involved, and the positioning accuracy in the vertical direction can be improved.

The application provides a kind of physical prior driven three-dimensional electromagnetic scattering calculation method of deep learning under the condition that three-dimensional scatterer shape and electric parameter are not completely known, can utilize multi-angle observation data, realize the solution to three-dimensional scattering characteristics under the condition that scatterer shape and electromagnetic parameter are not completely known.Method first carries out pre-processing to the data of known part of scatterer, then uses neural network to predict the multi-angle internal total field of complete three-dimensional scatterer, based on the predicted multi-angle internal total field of complete three-dimensional scatterer, uses moment method to calculate the scattering field generated by three-dimensional scatterer under the irradiation of different angle incident wave.The application can use multi-angle scattering field (observation / measurement) data and known physical prior information to predict the scattering characteristics of three-dimensional scatterer whose shape and electric parameter are not completely known.

This invention relates to a microwave imaging method integrating Born iteration and compressed sensing, comprising: establishing a two-dimensional electromagnetic inverse scattering integral equation model, discretizing the imaging region, setting iteration and prior parameters, and initializing the contrast and total field as background values ​​and incident fields, respectively; based on the total field of the previous iteration, constructing linearized scattering equations for multiple incident angles, defining single-view inversion as an independent task, and integrating them into a multi-task set sharing sparse priors; employing the MT-BCS algorithm to jointly solve the observation equations using shared hyperparameters, and outputting the updated contrast distribution; solving the state equation based on the new contrast to complete the total field update; outputting the imaging result if the convergence condition or the maximum number of iterations is met; otherwise, continuing iteration. This invention applies joint sparsity constraints through a multi-task joint inference mechanism, mining the geometric structure consistency of multi-view data, and overcoming the shortcomings of traditional single-task methods such as low signal-to-noise ratio, low reconstruction accuracy when measurement data is limited, and severe artifacts.

The invention discloses a high-precision seismic fluctuation input method and device for SSI analysis of a layered stepped site, and the method comprises the steps: building a two-dimensional stepped layered site model, and introducing a Y-shaped artificial boundary to divide the two-dimensional stepped layered site model into a central finite field, a left half infinite field and a right half infinite field; applying a zigzag-paraxial combined boundary on the Y-shaped artificial boundary to simulate the radiation damping effect of the left half infinite domain and the right half infinite domain; respectively solving the seismic response of the one-dimensional horizontal layering field models of the left half infinite domain and the right half infinite domain, and obtaining the free field response of the left boundary and the right boundary of the Y shape through time delay calculation; respectively decomposing respective total field responses into scattered field responses and free field responses, calculating respective infinite domain equivalent node forces and free field node forces according to the scattered field responses and the free field responses, superposing the infinite domain equivalent node forces and the free field node forces to form two groups of final equivalent node force vectors, and respectively applying the two groups of equivalent node force vectors to the left boundary and the right boundary to obtain a final equivalent node force vector. And high-precision input of far-field vibration in layered stepped field SSI analysis is realized.

The application describes a method (300) and processing device (46) for providing a scene segmentation map for a total field of view (12) of an image capturing device (10). The method (300) comprises obtaining (301) a scene segmentation map for the total field of view (12); receiving (302) an indication that a new focus value has been set for the image capturing device (10) for acquiring images of a current field of view (14); comparing (303) the new focus value with a stored focus value associated with a focus region (22) in the current field of view (14), wherein the stored focus value represents a previously used focus value; upon the new focus value deviating from the stored focus value more than a trigger threshold, triggering (305) a scene segmentation map update process; and otherwise maintaining (309) the scene segmentation map.

The application discloses a magnetic target positioning method based on geomagnetic total field vertical difference, utilizes a rotor unmanned aerial vehicle to carry an inertial navigation system and two vertically distributed optical pumping magnetometers, simultaneously measures geomagnetic total field data containing magnetic anomalies and real-time position data of the unmanned aerial vehicle when flying along a survey line, regards the magnetic target as a static magnetic dipole, takes the centers of the two optical pumps at the initial position as a coordinate origin, uses the magnetic moment of the magnetic target, position coordinates, known geomagnetic inclination and geomagnetic declination and real-time position coordinates of the two optical pumps to respectively represent the magnetic anomaly fields generated by the magnetic target at the positions of the two optical pumps, calculates the geomagnetic total field vertical difference of each point on the survey line by using the measurement values of the two optical pumps, jointly constructs a target function by using the magnetic anomaly difference values generated by the magnetic target at the positions of the two optical pumps, and estimates the position of the magnetic target by using a cuckoo optimization algorithm.

The embodiment of the invention relates to the technical field of video processing, and discloses a financial video understanding extraction method, device and equipment and a storage medium, and the method comprises the steps: obtaining a target frame set related to financial information in a to-be-processed financial video; sampling the target frame set to obtain a key frame set; for each key frame in the key frame set, extracting a field information set in the key frame by using an OCR model to obtain a field information set corresponding to the key frame; and performing aggregation processing on the total field information set by using an inter-frame information aggregation technology to obtain a target text, the total field information set comprising field information sets corresponding to the key frames in the key frame set. Sampling processing is utilized to screen out the key set from the target frame set, so that the number of processed frames is greatly reduced, and the extraction efficiency is improved. The field information sets of the plurality of key frames are integrated by utilizing an inter-frame information technology, and the field information with the highest accuracy is selected from the plurality of key frames, so that the accuracy of the target text is improved.

The invention discloses a large-loop source transient electromagnetic fast forward modeling method based on GPU acceleration, and the method comprises the steps: firstly carrying out the parameter setting and preprocessing, then segmenting a large-loop source into a north edge, a south edge, an east edge and a west edge, and carrying out the discretization of each edge into N electric dipoles through employing a Gaussian-Legendre quadrature method; constructing a loop edge-frequency sampling point-wave number-time channel four-level parallel computing architecture to compute each edge; wherein each side in the GPU adopts a frequency-wave number-time parallel computing architecture, and parallel computing is performed on each electric dipole, so that the frequency-time domain response of each electric dipole is obtained; and finally, after calculation of all the electric dipoles is completed, vectorization calculation and summation are carried out on transient responses of all the electric dipoles on the GPU, a large loop source total field response at the current observation point is obtained, and a final time domain electromagnetic field value is output. According to the method, the advantages of large-scale parallel computing of the GPU can be efficiently and fully played, so that the computing efficiency is effectively improved on the premise of ensuring the computing precision.

This invention provides a real-time magnetic anomaly target identification method and system based on a physically constrained neural network (PCNN). The method includes: acquiring spatial geomagnetic total field data; preprocessing the total field data to generate input samples and labeling them with category tags; designing a lightweight convolutional neural network (HNN) as the backbone network, introducing physical constraint terms, and constructing a PCNN model. The physical constraint terms specifically include: the magnetic field in the passive region should satisfy the Laplace equation and the magnetic anomaly signal should conform to the dipole field decay law; training and optimizing the PCNN model based on the labeled input sample data and simulated target data; receiving the magnetic signal stream in real time, inputting it into the trained PCNN model according to time windows, and completing the target identification and output. This invention addresses the technical problems of low identification accuracy, poor interpretability, and weak generalization ability in existing magnetic anomaly target identification methods under conditions of small samples and low signal-to-noise ratio.

The invention discloses a geomagnetic interference compensation method based on an AMS-CPO optimization algorithm. The method comprises the following steps: S1, installing an optical pump sensor and a three-axis fluxgate on an unmanned trolley, and collecting data; s2, establishing a target fitness function according to the T-L model; s3, estimating an optimal compensation coefficient by using an AMS-CPO algorithm according to the target fitness function; and S4, compensating the geomagnetic total field by using the estimated optimal compensation coefficient to obtain compensated residual magnetic interference. According to the geomagnetic interference compensation method based on the AMS-CPO optimization algorithm, interference compensation can be carried out on the total geomagnetic field by estimating the optimal compensation coefficient, and the compensation precision is improved. Compared with a traditional CPO algorithm and a particle swarm optimization algorithm (PSO algorithm), the algorithm of the invention can greatly improve the geomagnetic field measurement precision, and the convergence speed is high.

The application provides an aircraft aeromagnetic compensation method, system, device and medium, and relates to the technical field of aircrafts, and the magnetic field characteristic data and temperature characteristic data of the aircraft aeromagnetic of a current area are acquired; the total field value of the interference magnetic field corresponding to the current area is determined based on the magnetic field characteristic data; the total field value of the magnetic interference field corresponding to the current area is determined based on the total field value of the interference magnetic field and the total field value of the non-interference magnetic field; the magnetic interference characteristic matrix corresponding to the current area is determined based on the magnetic field characteristic data and the temperature characteristic data; and the compensation coefficient corresponding to the current area is determined based on the magnetic interference characteristic matrix corresponding to the current area and the total field value of the magnetic interference field, so that the comprehensive error compensation of the aeromagnetic is realized.

This invention relates to the field of geophysical exploration technology and discloses a three-dimensional polarizability inversion method based on cross-gradient constraints. The method includes the following steps: acquiring apparent resistivity observation data d_obsr and equivalent apparent resistivity observation data d_obsη; performing hybrid mesh partitioning on the computational domain to generate a hybrid mesh model containing triangular prism elements, tetrahedral elements, and pyramidal elements; and performing three-dimensional resistivity forward modeling based on the hybrid mesh model to obtain the total field potential. This three-dimensional polarizability inversion method based on cross-gradient constraints, by employing a hybrid mesh (combination of triangular prism, tetrahedral, and pyramidal elements) partitioning technique, can accurately fit undulating surfaces, fundamentally eliminating the terrain influence error caused by mesh simplification. Measured data show that the forward modeling response error at steep terrain measurement points can be reduced from 5.1% to 1.5% using traditional methods, effectively suppressing false anomalies and making the anomaly boundary more clearly delineated.

The application discloses a kind of based on conformal technology's core particle through silicon via interconnection structure signal integrity simulation excitation method, using time domain finite difference method analysis core particle interconnection structure application scene, to through silicon via structure model using conformal technology is analyzed;Overall calculation region is divided into excitation region and structure calculation region two sub-regions;Using total field / scattering field boundary technology, the result of excitation region is introduced as incident wave into structure calculation region, as excitation source to through silicon via structure is excited;The surface power integration at port in total field and scattering field is calculated, and by Fourier transform is converted into frequency domain calculation each port S parameter.The present application reduces the step approximation error of time domain finite difference method using conformal technology, by dividing the calculation region into two sub-regions solve the high-order mode crosstalk problem existing in typical coaxial structure such as through silicon via, and greatly improve the calculation precision of through silicon via structure signal integrity.

The invention discloses a 2-bit coding aperiodic reflective array antenna for near-field focusing, and belongs to the technical field of antenna engineering. According to the invention, the electromagnetic compatibility characteristic and the isolation between array elements are improved through the strip line of terminal short circuit and the shielding cavity fence; 90-degree reflection phase difference is realized through four states of the array element transmission line, and 2-bit array element coding is carried out; and analyzing and designing the irregular reflective array antenna by using a high-speed and accurate analysis method based on an equivalent scattering matrix model. Compared with a traditional reflective array antenna, the reflective array antenna has the advantages that contribution of a carrier platform, a supporting structure, feed source shielding and direct radiation and mutual influence among array elements to a total field of the reflective array antenna is fully considered, the reflective array antenna is suitable for any periodic and aperiodic arrays and any regular and irregular carrier platforms, the design flexibility of the reflective array antenna is greatly improved, and the design cost of the reflective array antenna is reduced. And the application range of the reflective array antenna is expanded.

The application discloses a magnetic total field anomaly data processing method and device and related equipment, and the method comprises the following steps: acquiring two-dimensional magnetic total field anomaly data uniformly distributed in a detection area, and acquiring first horizontal distribution data of the modulus of two-dimensional magnetic total field anomaly on each group of unit orthogonal bases based on the two-dimensional magnetic total field anomaly data, wherein the unit orthogonal bases are obtained by decomposing two-dimensional magnetic total field anomaly data generated by a magnetic dipole of a target body at any height; acquiring second horizontal distribution data of the energy of two-dimensional magnetic total field anomaly in a two-dimensional space spanned by each group of unit orthogonal bases based on the first horizontal distribution data; and determining the horizontal coordinate of the target body based on the second horizontal distribution data. The application converts two-dimensional magnetic total field anomaly data into two-dimensional energy distribution, can improve the signal-to-noise ratio of data, effectively improves the accuracy of target detection, can determine the horizontal coordinate of the target, and realizes the positioning of the target in the horizontal direction.

The invention discloses an absolute geomagnetic field vector observation method, and relates to the technical field of geomagnetic measurement. The absolute geomagnetic field vector observation method comprises the following steps: correcting drift values of three axes (A axis, B axis and C axis) of a three-axis fluxgate sensor for observation by using a three-axis magnetic sensor for correction and a magnetic shielding cylinder; determining the relative relationship between the three axes and the optical axis of the telescope of the non-magnetic theodolite, determining the absolute orientation of the three axes, and calculating the geomagnetic field component under the geographic coordinate system by combining the magnetic field readings of the three axes; the absolute total field intensity of the geomagnetic field observed by the total field sensor is used for correcting the observation error of the three-axis fluxgate sensor to obtain a corrected absolute geomagnetic field vector (including an absolute geomagnetic declination angle and a geomagnetic inclination angle); during the period, the three-axis magnetic sensor for correction and the magnetic shielding cylinder are used for automatically correcting the three-axis fluxgate sensor for observation. By implementing the absolute geomagnetic field vector observation method provided by the invention, high-precision absolute automatic continuous observation of three parameters including the geomagnetic field intensity, the geomagnetic declination and the geomagnetic dip angle can be realized.

The present application relates to a sighting lens, which comprises, in order from the object side to the image side along the optical axis, a first lens with positive refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, a fifth lens with negative refractive power, a sixth lens with positive refractive power, a seventh lens with positive refractive power, an eighth lens with negative refractive power, and a ninth lens with positive refractive power; the effective focal length F6 of the sixth lens and the effective focal length F of the sighting lens satisfy the following relationship: 0.2 <= F6 / F <= 2.0; the effective focal length F7 of the seventh lens and the effective focal length F of the sighting lens satisfy the following relationship: 0.09 <= F7 / F <= 0.30. The sighting lens of the present application has at least one of the following characteristics: super-telephoto, miniaturization, wide spectrum (430nm-940nm), high resolution, low chromatic aberration, good thermal stability (-30-70 DEG C), total field illumination >=99%, lens chief ray angle CRA <1.0 DEG.

The invention discloses a multi-model self-adaptive inertial geomagnetic multi-parameter matching navigation method, which comprises the following steps: acquiring an actual measurement position and an actual measurement attitude of an underwater vehicle and a geomagnetic total field actual measurement value at the same moment; calculating a geomagnetic gradient measured value at the same moment according to the geomagnetic total field measured value; respectively carrying out linear interpolation on the geomagnetic total field reference map and the geomagnetic gradient reference map to obtain a geomagnetic total field theoretical value and a geomagnetic gradient theoretical value corresponding to the geomagnetic total field reference map at the same moment; constructing a Kalman filter bank, and performing Kalman filtering estimation to obtain a matching position; calculating to obtain a weight corresponding to each matching position; and carrying out weighted fusion processing to obtain a comprehensive matching position. According to the method provided by the invention, filtering divergence is suppressed by using multi-model adaptive estimation, and the positioning precision is improved to a sub-grid level; through an intelligent weight distribution mechanism, the advantages of the geomagnetic total field and the gradient are comprehensively utilized, and the robustness of the navigation system is effectively improved.

The application discloses a magnetic total field vertical gradient data processing method and device and related equipment, and the method comprises the following steps: acquiring two-dimensional magnetic total field gradient data collected by two magnetic total field sensors vertically arranged in a detection area, and the recording points of the two-dimensional magnetic total field gradient data are uniformly distributed in the detection area; based on this, first horizontal distribution data of the modulus of the two-dimensional magnetic total field gradient on each group of unit orthogonal bases is acquired, the unit orthogonal bases are obtained by decomposing the two-dimensional magnetic total field gradient data generated by the magnetic dipole of a target body at an arbitrary height; based on the first horizontal distribution data, second horizontal distribution data of the energy of the two-dimensional magnetic total field gradient in a two-dimensional space formed by the unit orthogonal bases is acquired; and based on the second horizontal distribution data, the horizontal coordinate of the target body is determined. The application can improve the signal-to-noise ratio of data, effectively improve the accuracy of target detection, and determine the horizontal coordinate of the target, thereby realizing the positioning of the target in the horizontal direction.

The application discloses a GPU acceleration-based large-loop-source transient electromagnetic fast forward method, which comprises the following steps: firstly, parameter setting and pretreatment are performed; then, the large-loop-source is divided into four edges of north, south, east and west, and each edge is discretized into N electric dipoles by using a Gauss-Legendre quadrature method; a four-level parallel computing architecture of loop edge-frequency sampling point-wave number-time channel is constructed to calculate each edge; wherein, the parallel computing architecture of frequency-wave number-time is used in each edge in the GPU to perform parallel calculation on each electric dipole, so that the frequency-time domain response of each electric dipole is obtained; finally, after the calculation of all electric dipoles is completed, the vectorization calculation and summation of the transient responses of all electric dipoles are performed on the GPU to obtain the total field response of the large-loop-source at the current observation point, and the final time domain electromagnetic field value is output. The above method can efficiently and fully exert the large-scale parallel computing advantage of the GPU, so that the calculation efficiency is effectively improved under the premise of ensuring the calculation precision.

The invention discloses a method for providing a scene segmentation map and a processing device. The present application describes a method (300) and a processing device (46) for providing a scene segmentation map of a total field of view (12) of an image capture device (10). The method (300) comprises: obtaining (301) a scene segmentation map of a total field of view (12); receiving (302) an indication that a new focal length value has been set for the image capture device (10) for acquiring an image of the current field of view (14); comparing (303) the new focal length value with a stored focal length value, the stored focal length value being associated with a focal region (22) in the current field of view (14), where the stored focal length value represents a previously used focal length value; triggering (305) a process of scene segmentation map updating when the new focal length value deviates from the stored focal length value by more than a trigger threshold; and otherwise, maintaining (309) the scene segmentation map.

The invention relates to a field line coupling simulation method under a complex terrain, belongs to the technical field of computational electromagnetism and electromagnetic compatibility, and solves the technical problem that the calculation precision is affected due to an edge effect existing in field line coupling calculation by a finite difference time domain method. The field line coupling simulation method comprises the following steps: establishing a layered irregular complex terrain and a closed TF / SF boundary; calculating an excitation field of a total field scattering field TF / SF boundary by adopting a fine line time domain finite difference method; and performing iterative calculation on field line coupling at the position of the cable by adopting a fine line time domain finite difference method to obtain a current I and a unit length charge Q at a cable sampling point. The method is used for field line coupling high-precision solution under the complex terrain.

The application discloses a kind of anisotropic medium three-dimensional transient geothermal field forward method, equipment and medium, by modeling target area, then target area is spatially discretized and time discretization, in space, using the iterative calculation of spatial domain total field temperature of space-wave number hybrid domain iterative method;In time, in combination with the recurrence formula of geothermal field of explicit difference format, the initial spatial domain total field temperature of next time node is calculated, then the spatial domain total field temperature of next time node is calculated using the iterative calculation of spatial domain total field temperature of space-wave number hybrid domain iterative method;In this way, the spatial domain total field temperature of all time nodes is forward calculated.This application realizes the anisotropic medium three-dimensional transient geothermal field forward, can reflect the dynamic change of geothermal field, combine space-wave number hybrid domain iterative method with geothermal field recurrence technique, ensure fine geothermal field forward, reduce the cost of calculation and storage, improve the calculation efficiency.