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130 results about "Scattering cross-section" patented technology

The scattering cross-section is a hypothetical area which describes the likelihood of light or other radiation being scattered by a particle, the scattering center. It is a measure of the strength of the interaction between the scattered particle and one or several scattering centers.

Phased array weather radar calibration method based on generalized metal ball calibration theory

The invention discloses a phased array weather radar calibration method based on a generalized metal ball calibration theory. Comprising the following steps: in a microwave anechoic chamber, collecting two-dimensional antenna pattern data of a phased array weather radar in at least one working mode and pointing to a plurality of different beams; performing numerical integration on the two-dimensional antenna pattern data, calculating a combined beam main lobe solid angle of the transmitting antenna and the receiving antenna, and calculating an equivalent beam width product; calculating a calibration theoretical reflectivity factor of the metal ball based on the product of the theoretical radar scattering sectional area and the equivalent beam width of the metal ball; actual detection echo data of the phased array radar on the metal ball under different working modes and beam pointing is acquired, and an actual reflectivity factor is calculated; and comparing the actual reflectivity factor with the calibration theoretical reflectivity factor to complete calibration of the phased array weather radar. Aiming at the non-Gaussian working mode of the phased array weather radar, the reflectivity factor of the phased array weather radar can be quantitatively evaluated, and the radar detection performance is improved.
Owner:长沙气象雷达标校中心

Broadband Radar Cross Section Reduction Metasurface with Reflection and Scattering Characteristics

The present invention discloses a broadband radar cross section reduction metasurface with reflection and scattering characteristics, which includes a number of square structural units arranged in a set manner. Each square structural unit includes a bottom metal plate unit, an upper special-shaped metal strip unit, and a dielectric substrate unit disposed between the bottom metal plate unit and the upper special-shaped metal strip unit. The present invention can integrate two special functions within a relatively wide frequency band, namely the reflection and scattering of incident electromagnetic waves, so as to achieve the functions of specular reflection and RCS reduction.
Owner:BEIJING INST OF TECH

Flexible conformal array structure scattering characteristic analysis method and device

The invention discloses a flexible conformal array structure scattering characteristic analysis method and device, and the method comprises the steps: carrying out the fitting of a whole flexible array surface arc length through employing a plurality of osculating circles through the evaluation of a flexible array surface structure, and determining the number of osculating circles divided by a whole arc length curve through iteration; constructing feature units to realize reconstruction of the whole flexible array plane, and calculating an initial excitation coefficient, a feature weight coefficient and a mutual coupling coefficient between the units of each flexible unit; and constructing and solving a balance equation to obtain an actual excitation coefficient of each flexible unit considering the mutual coupling effect, and calculating a total scattering field of the flexible array structure to obtain a radar cross section of the flexible array. According to the method, the scattering characteristic analysis of the flexible conformal array structure is realized, the problem of inconsistent deformation degree of each unit caused by the flexible structure is considered, a small number of characteristic units are used for replacing the units in the actual flexible array structure through an iteration mode, and the analysis efficiency is improved.
Owner:XIDIAN UNIV

Laser radar ranging process simulation method suitable for complex scene

The invention discloses a laser radar ranging process simulation method suitable for a complex scene. The method belongs to the field of full-waveform laser radar ranging simulation. The method comprises the following steps: setting initial parameters, and calculating to obtain a backscatter cross section function of a complex scene; an ideal echo signal is obtained through convolution; generating random noise and superposing the random noise with the ideal echo signal; filtering the signal on which the noise is superposed; carrying out adaptive threshold detection on the filtered signal to judge whether an effective signal exists or not; determining an echo pulse arrival time by using a standard waveform fitting method, and calculating to obtain a distance measurement result; and carrying out multiple detection to obtain laser radar ranging statistical characteristics. According to the invention, the Monte Carlo ray tracing algorithm is introduced to realize the calculation of the backscattering cross section function of the complex scene, the transmission process of the light beam in the complex scene is truly restored, and the adaptive threshold detection method is adopted to effectively reduce the false alarm probability of the laser radar system and improve the detection probability.
Owner:NANJING UNIV OF SCI & TECH

Wave-absorbing and diffuse-scattering mixed ultra-wideband RCS (radar cross section) reduction metasurface with wave-transparent window

The invention discloses an ultra-wideband RCS (radar cross section) reduction metasurface with mixed wave absorption and diffuse scattering and a wave-transparent window, and belongs to the technical field of electromagnetic metamaterials. The metasurface adopts a four-layer cascade structure and comprises a first layer of polarization conversion structure, a second layer of 2.5 D lossy structure, a third layer of Jerusalem cross-shaped lossy structure and a fourth layer of frequency selective surface structure. By loading a lumped resistor at a specific position and adopting a metal through hole interconnection technology, dual functions of radar cross section reduction in a 1-20GHz ultra-wideband and low insertion loss wave transmission in a 8-12GHz frequency band are realized. The structure of each layer adopts a highly symmetrical design and has the characteristic of polarization insensitivity, and meanwhile, by optimizing interlayer air gaps and dielectric material selection, the structure compactness is realized on the premise of ensuring the performance. The method has important application value in the aspect of integration of stealth equipment and a communication system.
Owner:JIAXING CMAG COMPOSITE MATERIAL CO LTD +1

Single-layer fully-polarized reflective double-sided image metasurface and design method thereof

The invention discloses a single-layer fully-polarized reflective double-sided image metasurface and a design method. The reflective double-sided image metasurface is composed of a positive structure metasurface, a complementary structure metasurface and an intermediate dielectric substrate. The positive structure metasurface is formed by periodically extending and arranging m * m polarization conversion units in a plane, and arbitrary polarization conversion and phase regulation and control of electromagnetic waves of a specific frequency band are achieved. The polarization conversion unit is composed of an upper-layer chamfered rectangular patch or elliptical patch metal; the complementary structure metasurface is formed by periodically extending and arranging m * m complementary I-shaped units in a plane, and radar cross section reduction of back incident electromagnetic waves is achieved. Each complementary I-shaped unit is composed of a circular ring groove and I-shaped ring groove metal. The reflective double-sided image metasurface can realize polarization conversion under the excitation of forward arbitrary polarization electromagnetic waves and is used for near-field energy detection, can reduce the radar cross section under the excitation of backward orthogonal electromagnetic waves, and has the advantages of high working efficiency, small thickness and the like.
Owner:AIR FORCE UNIV PLA

Large-scale cluster target electromagnetic scattering analysis method and system based on parallel equivalence principle

The invention discloses a large-scale cluster target electromagnetic scattering analysis method and system based on a parallel equivalence principle, and the method specifically comprises the steps: carrying out the geometric modeling and equivalent surface construction of each target unit in a cluster target, and generating discrete surface element information; starting a parallel computing process, and distributing a target-equivalent face by adopting a greedy algorithm; a calculation process group corresponding to each sub-domain is partitioned according to a two-dimensional Cartesian coordinate grid, a transfer operator matrix between the sub-domains is partitioned according to the same two-dimensional calculation process grid, global parallel iterative solution circulation is carried out, and the equivalent surface flow of the sub-domain is updated; and the converged equivalent surface flow of each sub-domain is used as an equivalent source, and the radar cross section RCS of the whole cluster target in the specified observation direction is synthesized through far-field radiation integration. The method has good parallel expandability and calculation efficiency, is suitable for complex and diverse cluster target scenes, reduces memory requirements and calculation time overhead, improves calculation efficiency, and is high in engineering practicability.
Owner:NANJING UNIV OF SCI & TECH

Multi-source remote sensing image fusion method, medium and system for ship detection

The invention provides a ship detection-oriented multi-source remote sensing image fusion method, a ship detection-oriented multi-source remote sensing image fusion medium and a ship detection-oriented multi-source remote sensing image fusion system, and belongs to the technical field of remote sensing images. Constructing an electromagnetic scattering constraint model based on physical optical approximation and a geometric diffraction theory to calculate a predicted value of the backscattering cross section of the target, introducing a fusion cost function, generating a fusion weight matrix by adopting an adaptive feature weighting model, and performing multi-scale fusion on the image through hypercomplex wavelet transform; and iteratively optimizing the fusion result by using an information diffusion heat conduction equation, and performing physical consistency correction to output an enhanced fusion image, thereby solving the technical problem of poor physical consistency of the fusion result caused by lack of physical model constraint when the synthetic aperture radar image and the multispectral image are fused.
Owner:CHINESE PEOPLES LIBERATION ARMY UNIT 95291

Radar near-field target polarization characteristic analysis method based on vector Green function

The invention relates to the technical field of radar target characteristic analysis, in particular to a radar near-field target polarization characteristic analysis method based on a vector Green function. Firstly, a target three-dimensional scattering point model is constructed, a coordinate-based scattering coefficient is defined, a full-polarization observation mode is designed, a near-field measurement matrix is calculated based on a vector Green function, and an observation model is constructed. Secondly, designing a fusion far-field constraint orthogonal matching pursuit (OMP) algorithm, realizing high-precision inversion of scattering coefficients, calculating a target far-field single-station RCS (HH / HV / VV mode) through dynamic polarization-based projection and phase compensation, and establishing a near-far field scattering characteristic mapping model; according to the method, near-field three-dimensional imaging and far-field polarization characteristic analysis are fused, the problem of insufficient cross polarization component recovery in a traditional method is solved, and the method has the advantages of high-resolution imaging, multi-physical field collaborative optimization, adaptive noise suppression and the like, and can be applied to the fields of stealth target recognition, radar cross section testing, unmanned aerial vehicle navigation and the like.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Method and system for predicting luminosity of low earth orbit satellite during transit period

The invention discloses a method and a system for predicting luminosity of a low-earth-orbit satellite during transit, and the method comprises the steps: obtaining historical observation data, and constructing a comprehensive parameter data set of luminosity, position and related observation information of the low-earth-orbit satellite at different observation moments; equivalently representing the optical scattering sectional area of the low-orbit satellite by using the sectional area of the sphere generating the same brightness; key factors influencing the equivalent sectional area are determined; integrating the obtained parameterized relationship of the equivalent sectional area into a ball model formula to obtain a luminosity prediction model; taking the obtained comprehensive parameter data set as the input of the luminosity prediction model, and optimizing the luminosity prediction model through a data driving method to obtain an optimized luminosity prediction model; and substituting to-be-predicted low-earth-orbit satellite data into the optimized luminosity prediction model to obtain a luminosity prediction value of the low-earth-orbit satellite in the transit period. According to the method, the correction ball model is fitted through observation data, the luminosity prediction model is constructed in combination with key parameters, and the brightness of the low-orbit satellite is accurately predicted.
Owner:NAT ASTRONOMICAL OBSERVATORIES CHINESE ACAD OF SCI

NRCS determination method for Ku wave band scatterometer under rainfall condition

The invention discloses an NRCS determination method for a Ku wave band scatterometer under a rainfall condition, and relates to the field of satellite ocean remote sensing and meteorological detection.The method comprises the steps that the action mechanism of rainfall on radar signals in the atmosphere is considered, and a sea surface radar back scattering theoretical model is constructed based on a wind-generated sea surface wave spectrum and a dual-scale Bragg scattering theory; obtaining a rainfall attenuation coefficient, a normalized radar backscattering cross section contributed by raindrop scattering and dual-polarization normalized radar backscattering cross sections of a C wave band and a Ku wave band based on a sea surface radar backscattering theoretical model; according to the rainfall attenuation coefficient, the normalized radar backscattering cross section contributed by raindrop scattering and the dual-polarization normalized radar backscattering cross sections of the C wave band and the Ku wave band, the normalized radar backscattering cross section of the Ku wave band scatterometer under the rainfall condition is obtained; according to the method, the accurate normalized radar back scattering cross section of the Ku wave band scatterometer is obtained under the rainfall condition.
Owner:HAINAN TROPICAL OCEAN UNIV

Circularly polarized antenna with RCS suppression characteristic

The invention discloses a circularly polarized antenna with an RCS (radar cross section) suppression characteristic in the field of antennas. The circularly polarized antenna comprises a first dielectric substrate and a second dielectric substrate which are stacked, a metasurface structure array is arranged on the first dielectric substrate; the metasurface structure array comprises a plurality of distributed metasurface units; the plurality of first metal patches are arranged to form a convex metasurface module, and the plurality of second metal patches are arranged to form a concave metasurface module; the convex metasurface module is embedded into the concave metasurface module to form a metasurface unit; a metal floor is arranged between the first dielectric substrate and the second dielectric substrate; the metal floor is provided with a coupling slot; one side, far away from the first dielectric substrate, of the second dielectric substrate is provided with a sequential rotation feed network; energy is input by the sequential rotation feed network, and the metasurface structure is excited through the coupling gap to form a radiation signal; good radiation performance is still kept on the premise that the radar cross section of the antenna is reduced.
Owner:HOHAI UNIV

Super scattering and zero forward scattering coordinated regulation and control system and method based on optical gain

The invention discloses a super scattering and zero forward scattering coordinated regulation system and method based on optical gain, and relates to the technical field of optical scattering enhancement. The method comprises the steps that a space rectangular coordinate system is constructed; the cylindrical scatterer is vertically placed along the z axis; a transverse magnetic wave emitted by an emitting device is incident along the x axis; the emitting device emits the transverse magnetic wave, the transverse magnetic wave interacts with the cylindrical scatterer, and a total magnetic field of a free space in coordinates of the cylindrical scatterer is detected by using a detection device. Scattering coefficients and a total scattering cross section of different scattering channels of the cylinder are obtained based on the total magnetic field, key parameters for controlling scattering intensity and directivity are obtained based on the scattering coefficients and the total scattering cross section, and a scattering pattern is obtained by adjusting the key parameters of the cylindrical scatterer. The invention provides a new way for designing advanced optical devices applied to the fields of sub-wavelength antennas, optical communication, radar sensing, imaging and the like.
Owner:ZHEJIANG UNIV

Method, system, equipment and medium for evaluating gas-bearing property of water-flooded area

PendingCN120669320ANuclear radiation detectionScattering cross-sectionThermal neutron capture
The invention discloses a method, a system, equipment and a medium for evaluating the gas-bearing property of a water-flooded area, and the method comprises the steps: confirming three pieces of quantitatively measured skeleton information and fluid medium information in a time domain through different minerals and fluid components, and calculating a fast neutron scattering cross section according to pulse neutron logging data; carrying out qualitative identification on the gas reservoir by combining the fast neutron scattering cross section and the stratum hydrogen-containing index; according to the fast neutron scattering cross section, the thermal neutron capture cross section, the hydrogen content index and the respective volume content, a linear equation set is established, and the simultaneous equation set is solved to obtain the content of different fluid components in the stratum. The gas reservoir evaluation method solves the problem that a conventional gas reservoir evaluation method is seriously influenced by detection depth, borehole environment, invasion, low contrast ratio and pore fluid properties, and does not depend on conventional logging curves and electrical characteristics.
Owner:PETROCHINA CO LTD

Laser radar temperature measurement method and device based on oxygen atom vibration Raman scattering

The invention discloses a laser radar temperature measurement method and device based on oxygen atom vibration Raman scattering, and particularly relates to the technical field of laser radar atmosphere detection, and the method comprises the steps: calculating a differential Raman scattering cross section value of a to-be-measured altitude in a resonance Raman scattering transition spectral line; constructing a radar parameter equation; determining a relational expression between the ratio of the Stokes Raman scattering signal to the anti-Stokes Raman scattering signal and the temperature; and determining the absolute temperature of the atmosphere at the altitude to be measured based on the differential Raman scattering cross section value of the altitude to be measured in the resonance Raman scattering transition spectral line and the relational expression of the ratio of the Stokes Raman scattering signal to the anti-Stokes Raman scattering signal and the temperature. The method can overcome the problem that observation objects of a traditional method are limited in spatial distribution, is wide in temperature measurement range, is not easily influenced by other scattered signals, and is stable and reliable.
Owner:YANTAI UNIV

Test method for total scattering cross section of reverberation chamber stirrer based on mirror principle and application

The present application relates to the technical field of microwave measurement and reverberation chamber, and particularly relates to a test model of total scattering cross section of a reverberation chamber stirrer based on mirror principle and application, comprising: constructing a mirror model, and obtaining the number of mirror objects after multiple reflections and the total surface area of the mirror model; obtaining the time constant of the reverberation chamber; obtaining the damping time constant of the stirrer; and constructing the test model of the total scattering cross section of the reverberation chamber stirrer. The present application directly reflects the propagation mechanism of electromagnetic waves in the reverberation chamber and the scattering characteristics of the stirrer on the electromagnetic waves, has a certain guiding effect on the optimization of the stirrer and the test configuration, helps to understand, analyze and reduce the un-stirred energy in the reverberation chamber, and finally realizes the effective improvement of the performance of the reverberation chamber.
Owner:NORTHWESTERN POLYTECHNICAL UNIV +1

Satellite-borne SAR radiometric calibration precision evaluation method, system, medium and equipment

The invention provides a satellite-borne SAR radiometric calibration precision evaluation method and system, a medium and equipment, and belongs to the technical field of radiometric calibration, and the method comprises the steps: recognizing and analyzing an error source which affects the calibration precision; selecting a flat area as a calibration field according to the error source; arranging a plurality of standard calibration devices with known radar cross sections in an imaging band according to the satellite top crossing position and the wave position; controlling the satellite-borne SAR to irradiate the selected area at a specified wave position, acquiring and processing scene echo data, and generating an SAR image; according to the SAR image and a known radar cross section, calculating a radar cross section measurement value; and evaluating the satellite-borne SAR radiometric calibration precision according to the measured value of the scattering sectional area and the true value of the scattering sectional area. According to the method, multiple types of error sources in the radiometric calibration link are identified and analyzed, the calibration field is selected and multiple standard calibration devices are arranged based on the error sources, and the actually measured data are compared with the true value, so that the accuracy and credibility of radiometric calibration precision evaluation are improved.
Owner:CHINA AEROSPACE SCIENCE & TECHNOLOGY CORP COMMERCIAL SATELLITE CO LTD

A method for calculating the photon-atom coherent scattering cross section considering molecular interference effects

The present invention discloses a method for calculating a photon-atom coherent scattering cross section that takes into account the molecular interference effect. For a specific molecule, the Thomson differential scattering cross section of each element contained in the molecule is first calculated; secondly, a molecular interference function of the molecule to be calculated is obtained based on experimental measurement or molecular dynamics simulation; then, the molecular interference function is used to correct the atomic shape factor of each element contained in the molecule based on the independent atomic shape factor approximation method to obtain an atomic shape factor that takes into account the molecular interference effect; then, the factor is integrated to obtain an integrated atomic shape factor in a continuous energy ACE format database used by a Monte Carlo program; at the same time, the atomic shape factor that takes into account the molecular interference effect is used to correct the Thomson differential scattering cross section to obtain a differential scattering cross section of a coherent scattering reaction that takes into account the molecular interference effect, and the energy angle integration of the modified Thomson differential scattering cross section can be used to obtain a multi-group coherent scattering cross section used by a deterministic program.
Owner:XI AN JIAOTONG UNIV

A Simulation Method for Electromagnetic Scattering of Thin-Coated Targets Based on Schur Compensation Conditions

This invention belongs to the field of computational electromagnetics numerical simulation and provides a simulation method for electromagnetic scattering of thin-coated targets based on Schur complement preconditions. First, for the IBC scattering target to be solved, equivalent surface current and equivalent surface magnetic current are introduced as independent unknowns. The electromagnetic scattering solution equation is established using SDIE and then discretized. Next, the impedance matrix is ​​decomposed into near-field and far-field matrices using an octree structure. For the near-field matrix, key operator sub-blocks are explicitly assembled and extracted. Then, approximate operators in block diagonal form and Schur complement operators are constructed and approximately inverted. Simultaneously, the diagonal product of intermediate blocks is pre-calculated and stored based on the approximate operators. Finally, the constructed preconditions are applied to the GMRES iterative solver. When the iteration error reaches the preset convergence criterion, the current and magnetic current distributions on the target surface are output. Further calculations of radiation characteristic parameters such as the target's radar cross section are then performed, achieving low-cost, high-efficiency, and easily parallelizable electromagnetic simulation solutions.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

An image domain based near-field anomaly scattering filtering method

This invention relates to the field of RCS testing technology, specifically to an image-domain-based near-field anomalous scattering filtering method. The method first obtains a raw near-field image by near-field imaging of the acquired near-field swept data. Second, based on set anomalous scattering judgment conditions, the anomalous scattering centers are identified and extracted. Then, using a point target as a reference object, the scattering field distribution in the determined filtering area is simulated and reconstructed to generate a new near-field image. Finally, it is determined whether the new near-field image meets the anomalous scattering judgment conditions. If not, a filtered near-field image is generated. By identifying and removing scattering centers that do not belong to the test target from the two-dimensional image generated by the near-field imaging, near-field clutter suppression and higher-precision radar cross section testing are achieved.
Owner:CHENGDU AIRCRAFT INDUSTRY GROUP

A phased array tracking method based on four-dimensional joint weighted dynamic pre-switching

The present invention relates to a phased array tracking method based on four-dimensional joint weighted dynamic pre-switching, and belongs to the field of phased array communication technology. The present invention includes: updating the spatiotemporal correlation parameters to the target historical motion trajectory database, generating the target state prediction value based on the UKF prediction method; starting the four-dimensional joint gradual weighting program, performing linear phase interpolation in the time delay dimension, and generating a phase-continuous control signal; solving the mutual coupling matrix, establishing a cross-array phase mapping model based on cubic spline interpolation, and compensating for the residual phase error; dynamically adjusting the number of effective array elements participating in beam synthesis according to the real-time radar scattering cross section, generating the final beam pointing signal, and completing the stable relay tracking of the current cycle. The present invention solves the problems of phase jump and signal attenuation during multi-array switching, and is suitable for continuous tracking of UAVs in high-speed moving scenarios.
Owner:THE 54TH RESEARCH INSTITUTE OF CHINA ELECTRONICS TECHNOLOGY GROUP CORPORATION

A radar cross section test method based on deep learning and imaging inversion

The present application relates to a kind of radar scattering cross section test methods based on deep learning and ISAR imaging inversion, the method includes using ISAR imaging test mode to obtain target and calibration body broadband radar scattering echo signal, calibration processing and applying filter-inverse projection imaging algorithm to carry out ISAR imaging, application completes the deep learning model of accurate extraction ISAR image scattering signal area, application FFT transform-interpolation integral ISAR imaging inversion algorithm high-precision inversion reconstruction RCS value, change ISAR imaging aperture center azimuth angle traversal acquisition target all azimuth angle RCS data.The radar scattering cross section test method based on deep learning and ISAR imaging inversion provided by the present application solves the accurate extraction ISAR image scattering area and ISAR image high-precision inversion reconstruction RCS and other test practical problems, expands RCS data acquisition method.
Owner:CHINESE PEOPLES LIBERATION ARMY UNIT 95841

Spherical designer electromagnetic surface plasmon open resonator

A spherical designer electromagnetic surface plasmon open resonator is provided. The open resonator includes a resonator inner core and a resonator outer shell. The resonator inner core is located in an inner center of the resonator outer shell, and the resonator inner core and the resonator outer shell are coaxial. The disclosure provides a device that implements the superscattering function for incident waves in all incident directions and in all polarization directions, and a spherical open resonator is implemented. The scattering cross section of the disclosure can be more than five times greater than that of a metal sphere of the same size, and the operating frequency can be flexibly designed. By utilizing the characteristic that the scattering cross section of the spherical designer electromagnetic surface plasmon resonator is much greater than its own geometric cross section, the electromagnetic super-scattering device can be implemented.
Owner:ZHEJIANG UNIV

Radar cross section (RCS) acquisition method based on CBFM-AIM-EDM

The application provides a radar scattering cross section (RCS) acquisition method based on CBFM-AIM-EDM, and the implementation steps are as follows: initializing parameters; calculating main characteristic basis functions of each sub-region based on CBFM-AIM; calculating secondary characteristic basis functions of each sub-region based on CBFM-AIM-EDM; constructing a reduction matrix and acquiring the radar scattering cross section (RCS). The main characteristic basis functions and the secondary characteristic basis functions of each sub-region are calculated by using the characteristic basis function method (CBFM), then the RWG basis functions and their divergence on each sub-region can be projected on the matrix grid respectively by using the adaptive integration method (AIM) to obtain the Topelitz matrix, so that the calculation speed is accelerated, the RCS acquisition efficiency is improved under the condition of ensuring the accuracy, and the coupling between two sub-regions of the target is equivalent to the coupling between equivalent dipoles by using the equivalent dipole moment method (EDM), so that the RCS acquisition efficiency is further improved.
Owner:XIDIAN UNIV

Statistical scattering method for clutter particles in the environment in radar detection

This invention belongs to the field of radar signal processing and target detection technology, specifically relating to a statistical scattering method for clutter particles in radar detection. The method includes: acquiring single scattering parameters and simulation control parameters of the clutter particles; dynamically determining the simulation space length based on the single extinction coefficient and asymmetry factor; initializing a quasi-Monte Carlo low-discrepancy sequence; after initializing each photon packet, randomly generating a propagation step size and updating the cumulative propagation step size; when the photon packet does not exceed the boundary, determining whether scattering has occurred based on the single extinction coefficient and cumulative propagation step size; if scattering has occurred, updating the scattering direction based on the Henyey-Greenstein phase function and attenuating the energy weight; employing an adaptive dynamic threshold roulette wheel mechanism to dynamically adjust the survival probability based on scattering efficiency, photon position, and propagation direction, and maintaining statistical unbiasedness through energy weight compensation; after traversing all photon packets, calculating the total transmitted energy and total reflected energy, and calculating the equivalent extinction coefficient and radar cross section. This invention significantly improves simulation efficiency while ensuring statistical accuracy through physically guided importance sampling and a quasi-Monte Carlo low-discrepancy sequence, providing reliable support for radar anti-environmental clutter interference design.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA +1

Cross section generation method and equipment based on flux moment homogenization and transport correction coupling, and storage medium

The invention relates to the technical field of neutron transport numerical calculation, in particular to a cross section generation method and device based on flux moment homogenization and transport correction coupling and a storage medium, and the method comprises the steps: S1, building a geometric model of a reactor assembly or lattice cell, carrying out the energy Monte Carlo calculation, and generating a conventional cross section based on statistical data; s2, extracting a spherical harmonic function flux moment and a total reaction rate moment, calculating a total cross section spherical harmonic function correction term, and introducing a conventional scattering cross section to complete flux moment homogenization correction; and S3, exporting a first-order scattering matrix, carrying out transport correction to obtain a transport correction term, and correcting the conventional cross section according to the transport correction term and the total cross section spherical harmonic function correction term to generate a final multi-group cross section. According to the method, the anisotropies of the total cross section and the scattering cross section are synergistically corrected, the calculation precision of the method in the strong anisotropy problem is improved on the premise of keeping the standard cross section data structure, and the compatibility with a widely applied reactor core calculation program is ensured.
Owner:SHANGHAI JIAOTONG UNIV

A method for estimating radar cross section of dielectric-coated targets

The present invention discloses a method for estimating the radar cross section of a dielectric coated target, which relates to the field of radar application and is applicable to dielectric coated targets of electrically large size, and improves the calculation efficiency of the radar cross section while ensuring the calculation accuracy. The present invention is based on the characteristics of the target coating medium, and adopts a stepping method to calculate the reflection coefficient of the target surface; then the induced electromagnetic currents of different facets after the target is segmented are calculated respectively; based on the induced electromagnetic currents of different facets, the scattered electric field of each facet of the target is calculated respectively, and the scattered electric fields of the visible facets are summed to obtain the total scattered electric field of the target, and the radar cross section RCS is calculated accordingly. The present invention can be applied to the electromagnetic characteristic analysis of dielectric coated targets of electrically large size, and improves the calculation accuracy while ensuring the calculation efficiency.
Owner:XIDIAN UNIV

A phased array weather radar calibration method based on generalized metal sphere calibration theory

The application discloses a phased array weather radar calibration method based on generalized metal ball calibration theory. The method comprises the following steps: collecting two-dimensional antenna pattern data of a phased array weather radar under at least one working mode and multiple different beam directions in a microwave darkroom; performing numerical integration on the two-dimensional antenna pattern data, calculating a combined beam main lobe real solid angle of a transmitting antenna and a receiving antenna, and calculating an equivalent beam width product; calculating a calibration theory reflectivity factor of a metal ball based on a radar scattering cross section of the metal ball and the equivalent beam width product; acquiring actual detection echo data of the phased array radar on the metal ball under different working modes and beam directions, and calculating an actual reflectivity factor; and comparing the actual reflectivity factor with the calibration theory reflectivity factor, thereby completing calibration of the phased array weather radar. The application can quantitatively evaluate the reflectivity factor of the phased array weather radar in a non-Gaussian working mode, and improves radar detection performance.
Owner:长沙气象雷达标校中心

Spherical designer electromagnetic surface plasmon open resonator

A spherical designer electromagnetic surface plasmon open resonator is provided. The open resonator includes a resonator inner core and a resonator outer shell. The resonator inner core is located in an inner center of the resonator outer shell, and the resonator inner core and the resonator outer shell are coaxial. The disclosure provides a device that implements the superscattering function for incident waves in all incident directions and in all polarization directions, and a spherical open resonator is implemented. The scattering cross section of the disclosure can be more than five times greater than that of a metal sphere of the same size, and the operating frequency can be flexibly designed. By utilizing the characteristic that the scattering cross section of the spherical designer electromagnetic surface plasmon resonator is much greater than its own geometric cross section, the electromagnetic super-scattering device can be implemented.
Owner:ZHEJIANG UNIV

Space target laser radar scattering cross section simulation method, device, equipment and medium

The application relates to the field of laser radar detection, in particular to a space target laser radar scattering cross section simulation method, device, equipment and medium. The method comprises the following steps: projecting a triangular facet to a pixel plane perpendicular to an incident wave to obtain a projected facet with a depth attribute; regarding a pixel located in the projected facet in a circumscribed rectangle of the projected facet as an area pixel, and calculating a weighted average value of depth values of three vertex pixels according to the relative position of the area pixel in the projected facet to obtain a depth value of the area pixel; selecting an area pixel with the minimum depth value from at least one area pixel corresponding to any pixel in the pixel plane as a visible pixel, and regarding a projected facet with a proportion of the visible pixel to the area pixel exceeding a preset visible threshold as a visible facet; and calculating a laser radar scattering cross section based on the visible facet. The visible pixel is identified by performing pixel-level depth testing on the facet to determine the visible facet, so that an accurate laser radar scattering cross section is obtained.
Owner:齐鲁空天信息研究院