353 results about "Radar cross-section" patented technology

The invention belongs to the technical field of electromagnetic metasurfaces, and particularly discloses an RCS (radar cross section) in-band reduction circularly polarized metasurface antenna based on C-band satellite communication, which comprises a first metasurface layer, a first dielectric layer, a second metasurface layer, a second dielectric layer, a slotted metal plate, a third dielectric layer and a feed antenna layer which are stacked from top to bottom, wherein the first metasurface layer is formed by arranging four groups of unit structures in a mirror image mode in the two-dimensional direction, and two kinds of square chamfered patches in each group of unit structures are arranged in a non-contact mode; the second metasurface layer is formed by arranging four groups of unit structures in a mirror image mode in the two-dimensional direction, and the L-shaped resonance rings in each group of unit structures are arranged in an array mode; the total number of the square chamfered patches is the same as that of the L-shaped resonant rings, and one L-shaped resonant ring is arranged below each square chamfered patch. The antenna can be suitable for satellite communication, can realize reduction of a radar cross section at 4-10.5 GHz, and has a huge application value in the aspect of an electromagnetic stealth technology.

The invention discloses an airborne radar identification method based on multi-scale signal decomposition and depth feature fusion, belongs to the technical field of radar target identification, is used for unmanned aerial vehicle radar target identification, and comprises the following steps: decomposing an original dynamic radar cross section signal into a plurality of intrinsic mode components by adopting an adaptive noise complete set empirical mode decomposition method; self-adaptive wavelet soft threshold denoising is carried out on all the components in a unified mode so as to improve the signal-to-noise ratio and suppress background interference; effective components are screened out by calculating correlation coefficients of all intrinsic mode components and original signals, a radar cross section signal sequence after noise reduction is reconstructed, and multilevel feature fusion is carried out; and inputting the feature vector into a stacked auto-encoder deep neural network classification model, and introducing a particle swarm optimization algorithm to optimize the classification model. According to the method, the signal-to-noise ratio of the signal and the recognition accuracy of the classification model in a low signal-to-noise ratio environment are remarkably improved, and high-precision recognition and classification of different types of radar cross section targets are realized.

The invention discloses a high-sensitivity metal micro-strain sensor label and a detection method thereof, which are applied to the field of nondestructive testing and the field of structural health monitoring. The problems that an existing tag antenna is low in strain detection sensitivity and difficult in micro-strain detection are solved. The high-sensitivity metal micro-strain RFID sensing tag is attached to the surface of a component, when the tag deforms, the impedance change of the tag is Zsened, and the radar cross section changes accordingly; the reader can remotely monitor antenna parameters according to the change of the RCS0, the RCS1 and the intensity while communicating with the tag, so that the change of the intensity RSSI of an echo signal is deduced, and the deformation of the tag is indirectly known; when the impedance of the tag antenna changes, the resonant frequency of the tag changes accordingly, and the deformation information of the tag can be indirectly obtained by analyzing the deviation of the resonant frequency.

The invention discloses an unmanned aerial vehicle swarm distributed array antenna scattering characteristic analysis method, which comprises the following steps: obtaining infinitesimal dipole model parameters through geometric parameter equivalence of a single unmanned aerial vehicle, and calculating an initial excitation coefficient of each unmanned aerial vehicle; correcting the initial excitation coefficient of each unmanned aerial vehicle to obtain an unmanned aerial vehicle feature weight coefficient; constructing an attitude relation correction mutual coupling coefficient in an ideal state through translation and rotation when the configuration of the unmanned aerial vehicle array is changed; constructing a mutual coupling matrix, and obtaining an in-matrix excitation coefficient of each unmanned aerial vehicle under the consideration of a mutual coupling effect; and constructing and solving a balance equation, calculating an actual excitation coefficient considering a mutual coupling effect, calculating a total scattering field of the unmanned aerial vehicle array, and obtaining a radar cross section of the unmanned aerial vehicle array. According to the invention, the scattering characteristic analysis during the change of the array configuration of the unmanned aerial vehicle is realized, the problem of complex model scale in grid analysis is avoided, and the analysis efficiency is improved.

The invention belongs to the technical field of superconducting wires, and relates to a niobium-tin composite superconducting wire and a preparation method thereof. The invention provides a Nb3Sn composite superconducting wire. The Nb3Sn composite superconducting wire sequentially comprises an Nb3Sn superconducting wire core, a barrier layer, a stable layer, a transition layer, a substrate layer and a functional layer from inside to outside, the transition layer is formed by mixing copper and a dielectric polymer, and the copper content is continuously decreased in a gradient manner from inside to outside; the substrate layer is the dielectric polymer; the functional layer is a plurality of protruding metal microstructures. According to the invention, the functional layer with the broadband electromagnetic stealth function is integrated on the basis of the Nb3Sn superconducting wire rod, so that the radar cross section is obviously reduced while the Nb3Sn superconducting wire rod bears high-density superconducting current and generates a strong magnetic field, and the technical problem that a high-field superconducting magnet system is easy to detect in an electromagnetic environment is solved.

An unmanned aerial vehicle (UAV) identification method based on blind source separation and deep learning is disclosed, in the method, firstly, the one-dimensional radar cross section millimeter wave data set of the UAV is acquired, and the mixed signal is obtained by mixing, and the improved FastICA algorithm is used to separate it. Secondly, the separated signal is converted into a two-dimensional image by data transformation, and the two-dimensional image is augmented, the obtained data set is divided into training set, validation set and test set. Thirdly, establish a UAV classification model based on Improved ResNet18 and train this model on the training set to achieve UAV classification. In the present invention, the training time of the network is not greatly increased while the network identification accuracy is improved, so that it can well complete the UAV type identification, and the design is more reasonable and effective.

The invention discloses a broadband circular polarization metasurface antenna with a low radar cross section. The broadband circular polarization metasurface antenna is composed of a top layer 4 * 4 antenna array, a middle layer metal ground, a bottom layer one-to-sixteen sequential rotation feed network and two dielectric plates among the three layers. The antenna array is composed of four subarrays which are arranged in a 2 * 2 period, and the four groups of subarrays are symmetrical up and down and left and right along the center of the antenna array and are arranged in a chessboard shape. Each antenna unit in the antenna array comprises a bow-tie-shaped metal patch, and the patch is connected with the output end of the feed network at the bottom layer through a first metalized through hole; the feed network is composed of three one-to-two second-order Wilkinson power dividers, four 90-degree phase shifters, twelve T-shaped power dividers and a plurality of sections of 50-ohm microstrip lines. Through fusion design of the antenna and the metasurface, the problem that in the design process of the metasurface antenna with the low radar cross section, the antenna aperture is increased due to the fact that the antenna and the metasurface are independently designed firstly and then integrated is solved, and the low radar cross section characteristic of the broadband and the high-performance circular polarization radiation characteristic are achieved.

The invention provides a low-scattering carrier for an airfoil front edge RCS test, the low-scattering carrier comprises a front edge cover plate and a carrier main body which are detachably connected, the carrier main body and a carrier end face are of an integrally formed metal hollow structure, the front edge of the carrier main body is of a linear structure attached to an airfoil front edge wave-absorbing structure, and the front edge of the carrier main body is of a rectangular structure attached to the airfoil front edge wave-absorbing structure. The rear edge of the carrier body is of a linear structure parallel to the front edge. According to the low-scattering carrier, the drop-shaped design is adopted, the carrier end face and the carrier body are integrally formed, and the airfoil front edge and rear edge parallel structure is used, so that the influence of the edge on angular domain scattering assessment is reduced, and the vertical polarization and horizontal polarization electromagnetic scattering characteristics of the carrier are greatly reduced; and the stealth performance of the carrier in various radar environments is further improved. The low-scattering carrier provided by the invention has a good traveling wave suppression effect, and in an X wave band 0-50 degrees range, the RCS mean value of polarization in the horizontal direction can reach-45dBsm, and the RCS mean value of polarization in the vertical direction can reach-40dBsm.

Methods and systems are described for split ring resonators. The split ring resonator can work as a filter that blocks 0.6GHz to 1GHz and thus acts as a tuning element and reduces coupling between columns. Certain features, such as trace elements, can reduce the Radar cross section at mid band frequencies (1.4GHz-2.6GHz) thereby unaffecting the mid bands radiators. Embodiments can also boost return loss, which is very uncommon on several other tuning pieces in the prior art.

Wireless devices are commonly carried in fabric-based apparel. Printing metamaterial structures on fabric substrates allows for the ability to create fabric metamaterial layers. A reconfigurable RF based fabric system simply by physically removing or adding different fabric-based metamaterial layers to different regions of the apparel. The fabric-based metamaterial can be used in various filtering applications where the control of phase, reflection angle, refraction angle, polarization, absorption, and transmission of the impinged electromagnetic wave can all be manipulated. Additionally, sophisticated metamaterial systems can be created by combining different metamaterial layers separated above each other. A controllable absorber metamaterial system can be made consisting of two layers. The first layer an electronically controllable that can controllably change between a band-pass and band-reject filter in a relevant frequency band and a second absorptive layer. Vehicles with adjustable metamaterial absorber systems, integrated on the outside or inside of the RF transparent fuselage, have the ability to control their radar cross section dynamically for the purposes of evading detection or spoofing their size by looking larger or similar to vehicles of different radar cross section.

The invention discloses a fast near field extrapolation RCS calculation method based on a back propagation method. The method comprises the following steps: calculating an emission coefficient of each emission antenna; establishing a receiving antenna array for each transmitting antenna, and measuring an electric field value of each receiving antenna; establishing a tangential electric field equation based on the electric field value and position distribution of the receiving antenna as the input of near field extrapolation; solving the tangential electric field equation based on a back propagation method, and obtaining a far-field electric field value in the target direction; multiplying the emission coefficient of each emission antenna by the far-field electric field value of the target direction and then superposing to obtain a total far-field electric field value of the target direction; and calculating a far-field radar cross section according to the total far-field electric field value in the target direction, and completing near-field extrapolation RCS calculation. According to the method, the calculation speed of the whole single-station RCS near-field extrapolation is improved.

The invention relates to the technical field of wireless communication and antenna design, and discloses a circularly polarized antenna based on a multi-mode frequency selective surface, an integration method and a terminal. A wave absorbing layer, a first diffuse reflection layer and a second diffuse reflection layer are sequentially integrated on the circularly polarized antenna body from top to bottom. Wherein the circularly polarized antenna body has a working frequency band, the wave absorbing layer has a wave absorbing frequency band, the first diffuse reflection layer has a first diffuse reflection frequency band, and the second diffuse reflection layer has a second diffuse reflection frequency band; the working frequency band, the wave absorbing frequency band, the first diffuse reflection frequency band and the second diffuse reflection frequency band are efficiently integrated, the requirements for high-flexibility radiation and strong electromagnetic stealth are met, and the design of the multi-mode radiation stealth integrated array antenna is achieved. According to the invention, the out-of-band radar cross section (RCS) can be efficiently suppressed while the radiation efficiency in the working band of the antenna is not influenced, and the fusion target of high-performance radiation and ultra-wideband RCS suppression stealth is fundamentally completed.

The invention discloses a scattering center modeling method under continuous distance variation, which comprises the following steps of: performing far-field frequency sweeping, azimuth sweeping and pitching sweeping three-dimensional radar scattering cross section simulation on a target by adopting simulation software to obtain far-field three-dimensional scattering data, and performing near-field to far-field scanning distance radar scattering cross section simulation on the target to obtain continuous distance scattering data; according to the far-field three-dimensional scattering data, scattering images of a target in three dimensional directions are obtained; performing amplitude parameter estimation to obtain a target three-dimensional scattering center model; the distance and the attitude angle from the antenna to each scattering center are obtained, a plurality of scattering fields of each scattering center are reconstructed, and a total scattering field is obtained after vector superposition. According to the method, the amplitude of the scattering center is corrected through the position and angle geometrical relationship between the scattering center and the near-field antenna, scattering data at any distance can be reconstructed through far-field data, and the modeling efficiency is greatly improved while the modeling precision is ensured.

The invention discloses a method for estimating a radar scattering cross section of a coated medium target, relates to the field of radar application, is suitable for an electrically large coated medium target, and improves the calculation efficiency of the radar scattering cross section while ensuring the calculation precision. The method comprises the following steps: calculating a reflection coefficient of a target surface by adopting a stepping method based on target coating medium characteristics; respectively calculating induced electromagnetic currents of different surface elements after the target is subdivided; based on the induction electromagnetic currents of different surface elements, the scattering electric field of each surface element of the target is calculated, the scattering electric fields of the visible surface elements are summed to obtain the total scattering electric field of the target, and the radar cross section RCS is calculated according to the total scattering electric field. The method can be suitable for electromagnetic characteristic analysis of the electrically large-size coating target, and the calculation precision is improved while the calculation efficiency is ensured.

The invention relates to a phased array tracking method based on four-dimensional joint weighted dynamic pre-switching, and belongs to the technical field of phased array communication. The method comprises the following steps: updating space-time correlation parameters to a target historical motion track database, and generating a target state prediction value based on a UKF prediction method; starting a four-dimensional joint gradient weighting program, carrying out linear phase interpolation of a time delay dimension, and generating a control signal with a continuous phase; solving a mutual coupling matrix, establishing a cross-array-plane phase mapping model based on cubic spline interpolation, and compensating a residual phase error; according to the real-time radar cross section, the number of effective array elements participating in beam forming is dynamically adjusted, a final beam pointing signal is generated, and stable relay tracking of the current period is completed. The method solves the problems of phase jump and signal attenuation during multi-array-plane switching, and is suitable for continuous tracking in a high-speed moving scene of the unmanned aerial vehicle.

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.

The invention discloses a two-dimensional adjustable radar cross section enhanced surface. The enhanced surface is formed by adding a one-dimensional Van atta array of a phase shifter into a feeder line and copying the one-dimensional Van atta array on the other dimension. The one-dimensional Van atta array has a low profile, and under the condition that the incoming wave direction is known, electromagnetic waves are made to backtrack along the incoming wave direction by regulating and controlling the phase of a phase shifter in the array. The unit structure of the one-dimensional Van atta array is composed of an antenna and a phase shifter. The antenna is a slot-coupled feed microstrip antenna, the radiation patch is rectangular, the dielectric substrate is arranged below the radiation patch, the antenna grounding plane with a slot is arranged below the dielectric substrate, the slot is I-shaped, the second dielectric substrate is arranged, and the T-shaped antenna feed microstrip line is arranged below the second dielectric substrate. The antenna feed microstrip line is connected with the phase shifter, and the units of the array at equal intervals are connected in pairs through microstrip lines with the same length to form a one-dimensional Van atta array.

The invention discloses an icing monitoring method and system for a corner reflector deployed based on an unmanned aerial vehicle, and relates to the technical field of environment monitoring, and the method comprises the steps: deploying a corner reflector network, collecting radar cross-section characteristics and environment parameters to generate a data packet, and carrying out the icing monitoring based on the generated data packet; calculating a signal-to-clutter ratio, obtaining a standard deviation of target positioning and phase estimation by using a Cramer-Rao lower bound method, generating a dynamic weight by using the standard deviation, obtaining a corner reflector icing thickness estimation value through data fusion, and generating an optimized signal-to-clutter ratio based on the icing thickness estimation value; and carrying out cooperative judgment by utilizing the generated optimized signal-to-clutter ratio and combining the icing thickness and the attitude deviation, triggering combined adjustment based on a judgment result, and after the combined adjustment is triggered, obtaining the SAR image again and carrying out main and auxiliary image registration and interference pair optimization. According to the invention, the sensing precision and the monitoring robustness of the unmanned aerial vehicle on the state of the corner reflector in an icing environment are improved.

The invention provides a high-gain low-RCS (radar cross section) metasurface antenna with a wave beam deflection function, which belongs to the technical field of electromagnetic metamaterials and comprises an upper-layer metasurface and a lower-layer metasurface, and multifunctional regulation and control on an electromagnetic wave radiation scattering mode are realized by adopting the upper-layer metasurface and the lower-layer metasurface which are different in size. Wherein the upper-layer metasurface is a PCM-FSS scattering-transmitting integrated metasurface, and the lower-layer metasurface is a phase gradient metasurface. When the high-gain low-RCS metasurface antenna works in a radiation mode, the upper-layer metasurface emits spherical electromagnetic waves downwards, and when the spherical waves reach the lower-layer metasurface, the spherical waves are reflected into high-gain directional wave beams with the deflection angle being 34 degrees through phase compensation and penetrate through the upper surface to be radiated to a free space; when working in a scattering mode, the upper and lower layers of metasurfaces can deflect reflected waves of external electromagnetic waves to a non-threat angular domain direction. In the frequency band of 8-18 GHz, the RCS reduction amplitude reaches 10 dB or above, and in-band and out-of-band large-amplitude RCS reduction is achieved while high-gain radiation is kept.

The invention discloses a multilayer wave-absorbing material design method, system, medium and equipment, and the method comprises the steps: building a multilayer wave-absorbing material model through electromagnetic simulation software, taking a radar cross-sectional area RCS as an optimization target, and controlling FEKO to be within a specified target frequency band; sampling electromagnetic parameters in a value range by adopting a Latin hypercube sampling algorithm, performing parameterized simulation on the multilayer wave-absorbing material model, extracting radar cross-sectional area (RCS) values to form a parameter-RCS data set, generating an electromagnetic parameter-RCS data set, training a convolutional neural network, and obtaining a multi-layer wave-absorbing material model; establishing a nonlinear mapping model from the electromagnetic parameters to a radar cross-sectional area (RCS); embedding a proxy model obtained by training into a Bayesian optimization framework, applying an expected improved function to guide a search space, automatically optimizing an electromagnetic parameter combination, and performing FEKO full-wave simulation verification; if the RCS value of the optimization result is lower than the preset threshold value, iteration continues until the performance requirement is met, and the optimal electromagnetic parameter combination is output.

The invention relates to the field of radar detection, in particular to an unmanned aerial vehicle radar cross-sectional area full-angle measurement method, which comprises the following steps of: measuring the radar cross-sectional area of a to-be-measured unmanned aerial vehicle by using an unmanned aerial vehicle with radar equipment as a measuring device; the measuring device and the to-be-measured unmanned aerial vehicle are lifted to a preset height, and the measuring device points the antenna beam direction of the radar equipment to the to-be-measured unmanned aerial vehicle; recording radar output signal power under each group of attitude angles when the to-be-measured unmanned aerial vehicle flies to a specified position with a radar distance R from the measuring device; acquiring position information and attitude angle information of the measuring device and the to-be-measured unmanned aerial vehicle; and aligning the output signal power measured by the radar with the attitude angle of the to-be-measured unmanned aerial vehicle in time, and calculating the radar scattering cross-sectional area at each attitude angle to realize the full-angle measurement of the radar scattering cross-sectional area of the unmanned aerial vehicle. According to the method, the radar cross-sectional area of the unmanned aerial vehicle can be measured at a low altitude, interference of ground clutters on the radar is avoided, and the method is not limited by a measurement space.

The invention discloses a method for reducing RCS (radar cross section) of a low-scattering metal support. The RCS of the metal support is reduced by combining three different wave-absorbing materials and loading the wave-absorbing materials on the outer surface of the low-scattering metal support in different modes. The three wave-absorbing materials are respectively a wave-absorbing coating, a metamaterial and a hard wave-absorbing material. According to the invention, multiple wave absorbing materials are loaded on the low-scattering metal support, so that the low-frequency RCS performance of the low-scattering metal support can be effectively optimized, the coupling scattering between the support and the target is reduced, and the test requirements of more invisible targets can be met; the wave-absorbing material structure adopted by the method is light in weight, easy to process, transport, mount and maintain and relatively low in cost, and the mechanical property of the metal bracket is not influenced; the method is easy to implement, high in operability and capable of being used for upgrading and optimizing an existing low-scattering metal support.

A method, apparatus, and system for detecting presence of an object of low radar cross section RCS (250) in an environment (200) are provided. Radar detection at one or more radar frequencies greater than 2 GHz is used to determine a steady state response profile (300) of the environment (200). The steady state response profile (300) comprises at least one indication of one or more reflected signals (202) from an object of high RCS in the environment (200). Radar detection at the one or more radar frequencies is then used to determine a test response profile (600) of the environment (200). The test response profile (600) is compared with the steady state response profile (300) to determine a presence of a, object of low RCS (250) in the environment by identifying at least partial absence of at least one of the reflected signals (202) in the test response profile (600).

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.

The invention provides a radar waveform optimization method, system and device, a medium and a program product, and the method comprises the steps: transmitting a basic radar signal employing a basic waveform, and receiving an original echo signal formed by the reflection of a target; extracting a radar cross-sectional area of a target from the original echo signal to obtain a target RCS; traversing an RCS allowable range corresponding to each target type in the feature database, and determining a matching result; determining waveform control parameters of the radar waveform; an optimized radar signal employing the optimized waveform is generated and transmitted. According to the scheme, traversal matching is carried out on the target radar cross-sectional area measured in real time and the RCS allowable range in the feature database, adaptive optimization of the radar transmitted waveform on the current target RCS is realized, in addition, the candidate PRF is systematically traversed in the PRF feasible range corresponding to the target type, and the target type is more accurate. The adaptive matching of the PRF parameter with the current target RCS and the propagation condition is realized.

The invention discloses a NiZnCu ferrite composite metasurface with a P wave band broadband and a low RCS (Radar Cross Section) based on 1-bit coding. Firstly, the impedance matching condition of the ferrite is improved through Mn < 2 + > ion doping, so that when the thickness of the NiZnCu ferrite is 2 mm, effective wave absorption with the reflection loss smaller than-10 dB is achieved within the range of 0.25 GHz to 1.0 GHz. Furthermore, NiZnCu ferrite is combined with a sandwich structure (square metal sheet / FR4 / metal back plate, 6 mm) to construct a 1-bit coding metasurface structure unit, optimal array arrangement is obtained by adopting a genetic algorithm, and directional reflection is reduced to the greatest extent. And finally, full-wave simulation software is used for verification, and the result shows that the NiZnCu ferrite composite coding metasurface can further reduce the RCS by using the diffuse reflection effect on the basis of keeping the ferrite wave absorbing effect, the range of the RCS is 0.50 GHz-0. 75 GHz, and the maximum RCS reduction value can reach 29.4 dB.

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.

A human body pose estimation method based on radio frequency heatmap data enhancement is provided, including the following steps: firstly, obtaining the mesh data of human body pose, simulating a radar by using a physical optics method, and obtaining human body mesh features including a radar cross section by irradiating a human body mesh model; secondly, processing the human body mesh features including radar cross section to obtain preliminary simulated radar heatmaps; then inputting the preliminary simulated radar heatmaps into a heatmap conversion network map2map based on U-net, outputting synthetic radar heatmaps, and performing training; finally, combining the synthetic radar heatmaps with real radar heatmaps to construct a mixed data set, obtaining a human body pose skeleton through a human body pose estimation network based on the radar heatmaps, and performing training to complete the human body pose estimation.

The invention discloses a radar cross section measuring system and method, and relates to the technical field of electromagnetic scattering measurement, and the system comprises a transmitting antenna which is used for transmitting a step frequency broadband signal; the spiral phase plate rotating disc is vertically and rotatably arranged in front of the transmitting port surface of the transmitting antenna through a rotating assembly, a plurality of spiral phase plates with different modalities are arranged on the spiral phase plate rotating disc, and the spiral phase plates modulate step frequency broadband signals, generate vortex electromagnetic waves with corresponding modalities and transmit the vortex electromagnetic waves to a target on the same horizontal plane; the receiving antenna is used for receiving a near-field echo signal reflected by a target on the same horizontal plane; and the controller is used for receiving the near-field echo signals of the vortex electromagnetic waves in different modes and processing the near-field echo signals to obtain the radar cross section of the target. The radar cross section of a large-size radar target can be quickly, accurately and effectively obtained through the measurement system and the measurement method which are used for near-field measurement and are converted into far-field conditions.

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products are provided for object detection over a wireless network. A method performed by a wireless transmit / receive unit (WTRU) includes receiving, from a wireless network, a configuration that includes a configured target profile for a target and information indicative of an identification of the target, wherein the configured target profile comprises a radar cross section profile associated with the target; receiving at least one signal from the wireless network; generating a measured profile based on the at least one signal; determining that the at least one signal was reflected by the target based at least in part on the information indicative of the identification of the target and a comparison between the configured target profile and the measured profile; and performing sensing measurements associated with the target using the at least one signal based at least in part on the determination.