55results about How to "Improve stealth performance" patented technology

The invention discloses a tilting multi-rotor unmanned aerial vehicle and a tilting transition method, and belongs to the technical field of unmanned aerial vehicles. The tilting multi-rotor unmanned aerial vehicle comprises a fuselage, wings are symmetrically arranged on the two sides of the fuselage, wingtip small wings with rudders are arranged at the tail ends of the wings, and front tilting mechanisms symmetrically arranged relative to the fuselage are arranged at the front end of the fuselage; rear tilting mechanisms which are symmetrically arranged relative to the fuselage are arranged at the rear end of the fuselage, and a propeller is arranged in the middle of the rear end of the fuselage; the front tilting mechanism comprises a front propeller, the front propeller is connected with the fuselage through a tilting power structure, the rear tilting mechanism comprises a rear propeller, and the rear propeller is connected with the fuselage through a tilting power structure. According to the tilting multi-rotor unmanned aerial vehicle and the tilting transition method, the fuselage layout is matched with the front tilting mechanism and the rear tilting mechanism, the flight stability is improved, and higher air maneuverability is achieved.

The invention relates to an easy-to-replace marine single-point vibration reduction base which comprises a panel, the upper end face of the panel is matched with an auxiliary equipment base and provided with bolt holes used for being connected with auxiliary equipment, and a vibration reduction pad is laid between the panel and the auxiliary equipment base; the webs are vertically welded to the two sides of the lower end face of the panel to form a supporting structure of the vibration reduction base unit; wherein the face plate and the web plate are connected in a welded mode to form a vibration reduction base unit together, and the vibration reduction base unit is used for supporting and reducing vibration of auxiliary machine equipment. The damping device is compact and reasonable in structure and convenient to operate, the damping performance, the structural strength and the anti-corrosion capacity are remarkably improved by optimizing the structural design of the base, introducing the self-adaptive adjusting supporting device and the reinforcing rib plates and other innovative designs, and meanwhile installation and maintenance are facilitated. The beneficial effects jointly provide powerful guarantee for stable operation of ship power equipment, vibration and noise transmission are reduced, and comfort and invisibility of a ship are improved.

The invention discloses a multi-spectral-band compatible stealth coating based on a high-entropy alloy and a preparation method of the multi-spectral-band compatible stealth coating, and belongs to the technical field of functional high-entropy alloy coatings and preparation of the functional high-entropy alloy coatings. The problem that the visible light and infrared stealth effect of an existing stealth coating in a wide spectrum range is poor is solved. According to the preparation method, the high-entropy alloy film is prepared through the magnetron sputtering technology, efficient customization of material components and structures is achieved through scientific screening and optimal combination of elements and regulation and control of magnetron sputtering parameters, and therefore the high-entropy alloy film which is uniform, compact and excellent in performance is obtained. Test results show that the visible light band absorptivity of the high-entropy alloy coating is about 0.95, the infrared band emissivity of the high-entropy alloy coating is about 0.05, and multi-spectrum-band compatible stealth in the visible light and infrared spectrum range is achieved.

The invention relates to a preparation method of a high-temperature-resistant, radiation-resistant and stealth multifunctional integrated ceramic matrix composite material. The preparation method comprises the following steps: a, preparing coating slurry containing functional filling particles by ball milling and preparing silicon carbide (SiC) prefabricated cloth by a chemical vapor infiltration (CVI) process; b, uniformly coating the surface of the SiC prefabricated cloth with the mixed slurry, and neatly stacking and fixing; and c, depositing a silicon nitride (Si3N4) matrix on the laminated and fixed prefabricated body by a CVI (Chemical Vapor Infiltration) process for densifying. According to the preparation method provided by the invention, the integration of a high-temperature-resistant, radiation-resistant and stealth multifunctional structure of the ceramic-based composite material is realized, the mechanical property of the ceramic-based radiation shielding material in a high-temperature environment is enhanced, and the multifunctionality and high-temperature environment durability of the ceramic-based composite material are improved; meanwhile, the application range of the ceramic-based composite material is expanded.

The invention discloses a metasurface structure for reducing normal incident scattering of an antenna, and the metasurface structure employs a double-layer design, combines an absorption layer and a frequency selection surface layer, and achieves broadband absorption through a periodically two-dimensional unfolded microstrip patch unit and a three-layer resistor loading metal ring. Ansys electromagnetic field simulation software verifies that the structure effectively reduces the radar cross section of the microstrip antenna within the frequency band of 3-10 GHz, and ensures the normal work of the antenna at the same time. Through deep analysis and simulation optimization, key factors influencing the performance are determined, and the balance between the wave permeability and the wave absorbing property is realized. Besides, an adjustable resistance circuit, a reconfigurable mechanism, an intelligent algorithm and a sensor technology are integrated, the stability and the automation level of the antenna performance are further improved, and an effective solution is provided for improving the scattering reduction effect during forward incidence of radar waves.

The present invention relates to the technical field of electronic information equipment module assembly, and provides a method for optimizing the process of controlling molding defects before assembling electronic information equipment modules, including: selecting powder suitable for SLM laser selective melting; establishing an influence relationship model between process parameters and defect rate, optimizing the main process parameters of SLM laser selective melting; and positioning control of SLM printing by parameterized control of printing limit dimensions. The present invention combines technologies such as raw material composition analysis, microscopic morphology analysis, process parameter optimization, and precise printing positioning of limit dimensions for the first time, and proposes a method for optimizing the process of controlling molding defects before assembling electronic information equipment modules. The present invention is technologically advanced, mainly in that it not only meets the exploration of organizational formation rules, but also can obtain the optimal process parameter combination for printing, and can also control the formation of defects by precise positioning of the printing limit dimensions, and the technical advantages are very prominent.

The invention discloses a functional polystyrene infrared stealth thin film material and a preparation method thereof, and belongs to the technical field of functional material preparation. The infrared stealth thin film material of the functionalized polystyrene is prepared from the following components in parts by weight: 53 to 67 parts of a substrate thin film material, 8 to 12 parts of modified polystyrene and 0.8 to 1.3 parts of an adhesive, the substrate thin film material is prepared from m-iodoaniline, trimethylsilylacetylene, diisopropyl xanthate disulfide, tetramethylammonium hydroxide, polyvinylidene fluoride and polymethyl methacrylate, and the modified polystyrene is prepared from syringaldehyde, n-butyl bromide, 2, 2 '-dipyrrolyl methane, 2-thiopheneboronic acid and polystyrene cross-linked microspheres. The infrared stealth thin film material of the functionalized polystyrene prepared by the method has excellent stealth performance and mechanical performance.

The utility model belongs to the technical field of ships, and discloses a base, a ceiling lamp and a ship. The base is installed in an installation hole of a cabin roof structure of a ship, and the two opposite sides of the cabin roof structure are the invisible installation side and the illumination side respectively. The base comprises a base bottom structure, a liner structure, a transition structure and a ceiling lamp base structure. The gasket structure is of an annular structure and is connected to the invisible installation side, and the base bottom structure is connected to the gasket structure. The transition structure is located in the mounting hole, connected to the base bottom structure and extends towards the lighting side. The ceiling lamp base structure is connected to the side, away from the base bottom structure, of the transition structure. According to the base, the thickness of the bulged part of the ceiling lamp relative to the ceiling structure can be reduced, and the hiding effect of the ceiling lamp is improved.

This invention discloses an integrated S-curve nozzle design method and nozzle for aircraft with a blended wing-body layout, belonging to the field of aero-engines. The method comprises the following steps: obtaining the external surface of the blended wing-body aircraft and the position and size parameters of the engine exit; establishing a model of the S-curve section of the nozzle; obtaining and modifying the upper expansion surface at the nozzle exit; designing the centerline of the nozzle's aft deck using Lee curves; designing the double sidewalls of the nozzle's aft deck using Lee curves; obtaining the aft deck profile of the nozzle based on the centerline and double sidewalls determined in steps 3 and 4; and obtaining the sidewall profile of the nozzle exit. This invention solves the problems of limited space layout, large drop between the nozzle exit and the aircraft's tail edge, and maintaining the streamline of the aircraft's external surface after nozzle installation when designing an integrated S-curve nozzle in a blended wing-body layout.

The present invention discloses a bulkhead type hidden connection node, comprising a back plate, the back plate is provided with a through hole two, an internal threaded round steel cylinder is welded in the through hole two, the internal threaded round steel cylinder is provided with a threaded hole one and a conical groove, the bulkhead is provided with a through hole one at the connection node, the back plate is fixedly connected to the inner side of the bulkhead by welding, and the head of the internal threaded round steel cylinder is installed in the through hole one; when no equipment is connected, a cross countersunk bolt is fixedly installed in the threaded hole one; when erecting structures or mounting other equipment, a connection pair two is fixedly installed in the threaded hole one by an external hexagonal bolt one and an external hexagonal bolt two; after adopting the above structure, the bulkhead can be made flat without protrusions and beautiful in appearance; the radar reflection area is effectively reduced, so that the ship has better stealth performance; and a fixed connection node is provided when erecting external structures on the ship, which is simple to operate and safe and reliable.

The invention belongs to the technical field of electromagnetic scattering RCS extraction, and provides a supersonic target RCS characteristic extraction method under a terahertz wave band, which comprises the following steps: establishing a simulation model of a supersonic target; analyzing and testing the static characteristics of the supersonic target model; analyzing and testing the dynamic characteristics of the supersonic target model; modeling a plasma sheath model; and analyzing and testing the plasma sheath model. According to the method, an RCS characteristic detection method is explored by using FEKO software in a terahertz frequency band, and an efficient and accurate RCS detection method for a supersonic target is developed, so that the survivability and combat effect of the supersonic target in a complex electromagnetic environment are improved. According to the method, more valuable reference can be provided for the dynamic characteristic and static characteristic extraction process of the supersonic target in the flight process in the air, so that the design of the supersonic target can be further optimized conveniently, and the stealth effect of the supersonic target can be greatly improved.

The embodiment of the present disclosure discloses a flexible combined multifunctional broadband metasurface antenna for synthetic aperture radar, which comprises, from inside to outside, a core metasurface antenna located at the center and a peripheral metasurface located at the periphery, and the core metasurface antenna and the peripheral metasurface are connected through a U-shaped slot plug structure, wherein the core metasurface antenna and the peripheral metasurface can be replaced according to different application scenarios. The present disclosure has the characteristics of simple and reliable modular structure and flexible configuration according to task requirements; it meets the requirements of high-precision multiple transmission modes and corresponding amplitude-phase consistent multiple polarization reception of synthetic aperture radar, effectively increases the working bandwidth of the core antenna under low profile, reduces the radar scattering area of the antenna, optimizes the antenna radiation pattern and reduces the mutual coupling characteristics, further improves the imaging performance of the synthetic aperture radar, and reduces the signal-to-interference ratio of the synthetic aperture radar system.

The present invention discloses a method for designing an acoustic cloak coordinate transformation that is adaptable to different wave propagation directions, comprising the following steps: S1, determining the direction of the incident sound wave; S2, splitting the cloak and constructing a multi-center local coordinate system; S3, for each split part, performing coordinate transformation in the multi-center local coordinate system to obtain the cloak design parameters; S4, equating the cloak design parameters to two layers of alternately arranged isotropic media. Compared with the prior art, the beneficial effect of the present invention is that: considering the incident sound wave conditions in different propagation directions, a corresponding structural splitting scheme is designed according to the direction of the incident sound wave, so that the designed cloak can have good control over the incident sound waves at different angles.

The application discloses a rear body contraction type fluid thrust vector nozzle, which comprises a contraction section, a static pressure cavity, a main jet outlet, a control valve, a contraction wall surface, a secondary flow inlet and a wall surface secondary flow hole. The contraction section is arranged above and below the static pressure cavity, the main jet outlet is arranged at the tail end of the contraction section, the contraction wall surface is arranged at the tail of the static pressure cavity, the secondary flow inlet is arranged on the side of the rear body contraction type fluid thrust vector nozzle, and the wall surface secondary flow hole is arranged on the contraction wall surface. The static pressure cavity is in communication with the secondary flow inlet and the wall surface secondary flow hole, and the secondary flow inlet is controlled by the control valve. The rear body contraction type fluid thrust vector nozzle can realize jet vector deflection control while reducing the thickness of the rear body, has a good application prospect in the integration design of the fluid thrust vector and an aircraft, and can further promote the practical application of the fluid thrust vector nozzle.

The invention belongs to the field of radar signal processing, and discloses a joint resource scheduling and transmission zeroing method and system based on reinforcement learning. According to the method, in a scene that a plurality of transmitting nodes and a plurality of receiving nodes cooperatively execute a target tracking task in a receiving and transmitting separated MIMO radar network, aiming at the problem that a traditional radar resource allocation method lacks dynamic real-time adjustment capability and lacks comprehensive consideration on long-term performance of radar system resources, firstly, the dynamic real-time adjustment capability and the comprehensive consideration on the long-term performance of the radar system resources are considered; according to the method, joint optimization is carried out by considering transmission zero setting and resource scheduling, emission waveforms, residence time and power distribution of nodes are taken as optimization variables, then, cumulative signal-to-noise ratio constraints and the low interception probability of a whole task are considered at the same time, an optimization model for minimizing the interception probability is provided, and finally, for the optimization model, the optimization model is optimized. An algorithm based on reinforcement learning is adopted for solving, specifically, a PPO algorithm is adopted, and finally the low interception probability and the resource management efficiency are improved.

The invention provides a ship surface equipment base and a design method thereof. According to the ship surface equipment base, a base body comprises a panel, a web plate and a toggle plate, the web plate and the toggle plate are located below the panel and connected with the panel, the toggle plate is located in the web plate, and when the base body is in a floor type, the included angle formed by the web plate and a ship body ranges from 95 degrees to 99 degrees; when the base body is in a wall-mounted type, the included angle formed by the side surface and the bottom surface of the panel is 95-99 degrees; when the base body is in a cantilever type, the included angle formed by the panel and the toggle plate deviating from the side of the ship body is 80-85 degrees, and the included angle formed by the web plates on the two sides of the panel and the horizontal plane is 95-99 degrees. According to the ship surface equipment base provided by the invention, the shape RCS of a typical small base on a ship surface is reduced and optimized, and based on the optimized shape of the ship surface base, the RCS value of a large number of small reflection sources, namely the ship surface small equipment mounting base, can be effectively reduced, and the improvement of the radar wave stealth capability of the whole ship is facilitated.

The invention discloses an unmanned aerial vehicle cluster stealth flight path planning optimization design method based on task allocation, and the method comprises the steps: designing an unmanned aerial vehicle cluster stealth flight path planning comprehensive cost function based on task allocation based on the voyage cost of an unmanned aerial vehicle flight path, the degree of networking radar threat and the degree of antiaircraft gun threat; taking minimization of an unmanned aerial vehicle cluster stealth flight path planning comprehensive cost function based on task allocation as an optimization target, and taking meeting of flight path feasibility judgment, unmanned aerial vehicle cluster task allocation scheme requirements and unmanned aerial vehicle cluster dynamics limitation as constraint conditions, constructing an unmanned aerial vehicle cluster stealth flight path planning optimization model based on task allocation; and solving the optimization model by adopting an improved algorithm based on a genetic algorithm and an improved A * algorithm to obtain an optimal task allocation scheme of the unmanned aerial vehicle cluster. The application environment is more complex, the stealth performance of the unmanned aerial vehicle cluster is effectively improved, and meanwhile the comprehensive cost of task execution of the unmanned aerial vehicle cluster is effectively reduced.

This invention belongs to the field of metamaterials technology, specifically relating to an adjustable integrated absorption and reflection metamaterial structure. It includes several basic units arranged in a periodic array. Each basic unit comprises a resonant unit, a dielectric layer, and a reflector layer stacked sequentially. The dielectric layer is deformable to create a cavity between itself and the reflector layer or to fit tightly against it. The resonant unit includes four sequentially connected arc-shaped segments arranged centrally symmetrically. The ends of adjacent arc-shaped segments connect to form sharp corners extending towards the center of the resonant unit, with a gap between opposing sharp corners. This invention offers good reconfigurability, high flexibility, and deformability, allowing for easy adjustment of the state and switching of operating modes according to actual usage needs, achieving broadband absorption or complete reflection functions from 4.9 GHz to 16.3 GHz.

The invention provides a semi-embedded type air inlet channel with a step. The semi-embedded type air inlet channel comprises an air inlet channel inner channel, a first air inlet channel flow guide face, a second air inlet channel flow guide face extending forwards from the first air inlet channel flow guide face, and a step part higher than the second air inlet channel flow guide face. The height of the upper surface of the step part is the same as that of the upper surface of the lip cover, so that an air inlet of the air inlet channel has no additional orthographic projection area, the stealth performance is improved, and the windward resistance is reduced; the groove which is gradually expanded towards the two sides from front to back is concavely formed in the step part, and the sweepback triangular wedge which is higher than the second air inlet channel flow guide surface is formed at the junction of the front end of the first air inlet channel flow guide surface and the second air inlet channel flow guide surface, so that high-quality incoming flow at the air inlet is ensured.

The invention relates to a device for reducing an underwater vehicle pore cavity opening shear oscillation line spectrum peak value, and the device comprises a light housing which is provided with a plurality of openings in the surface; the bending plate assembly is connected to the edge of the side, facing fluid, of the opening, the bending plate assembly comprises a plate body, a fixed end and a height adjuster, the fixed end is fixedly connected to the edge of the opening, the plate body is rotationally connected to the fixed end, and the height adjuster is connected between the lower end of the plate body and the inner side of the opening. According to the device for reducing the shear oscillation line spectrum peak value of the pore cavity opening of the underwater navigation body, the inclined bent plate type structure is installed at the pore cavity opening of the underwater navigation body, and efficient hydrodynamic optimization of navigation bodies with different speeds is achieved. The obliquely-arranged bent plate assembly can effectively guide energy of the shear layer to be dispersed obliquely upwards, the collision energy of a shear layer vortex system and the trailing edge of the hole cavity is remarkably reduced, and then the energy feedback and shear oscillation line spectrum peak value is reduced.

The invention relates to a sealing structure for an airplane cabin door or a movable covering cap and an airplane in the field of aviation, the sealing structure is used for sealing a gap between the cabin door or the movable covering cap and an airplane body, the sealing structure comprises a supporting piece, the supporting piece covers the gap, and the supporting piece is used for supporting the cabin door or the movable covering cap. One part of the supporting piece extends to the outer side of the cabin door or the movable opening cover, and the other part of the supporting piece extends to the outer side of the machine body; the wave absorbing layer covers at least one side of the supporting piece; the conductive part is connected to the side, facing the gap, of the wave absorbing layer or the supporting part, and the conductive part penetrates through the gap and extends to the inner side of the cabin door or the movable opening cover. The sealing structure not only has excellent stealth performance, but also is simple to mount, the cabin door or the movable covering cap does not need to be punched, the influence on the structural strength of the cabin door or the movable covering cap is reduced, the manufacturability is better, and the cost is lower.

The invention discloses an infrared stealth film material of functionalized polystyrene and a preparation method thereof, and belongs to the technical field of functional material preparation. The infrared stealth film material of functionalized polystyrene is composed of the following components in parts by weight: 53-67 parts of a base film material, 8-12 parts of modified polystyrene, and 0.8-1.3 parts of an adhesive, wherein the base film material is prepared from meta-iodoaniline, trimethylsilyl acetylene, diisopropyl xanthate disulfide, tetramethylammonium hydroxide, polyvinylidene fluoride, and polymethyl methacrylate, and the modified polystyrene is prepared from syringaldehyde, n-butyl bromide, 2,2'-dipyrrolyl methane, 2-thiophene boric acid, and polystyrene cross-linked microspheres. The infrared stealth film material of functionalized polystyrene prepared by the method has excellent stealth performance and mechanical properties.

The open-air lamp for the ship comprises a remote light emitter, an open-air lamp body and an illumination optical fiber cable connecting the remote light emitter and the open-air lamp body, the remote light emitter comprises a light source, a light filter covering the light source and a light mixing assembly located on the light emitting side of the light filter, the light mixing assembly is used for collecting the light filtered by the light filter into the light mixing assembly, and the light mixing assembly is connected with an illumination optical fiber cable through a light source connector; the outdoor lamp body comprises a lamp holder and a reflecting device installed on the lamp holder, and the lamp holder is connected with the lighting optical fiber cable through a light source connector. According to the outdoor lamp for the ship, the problem that water vapor outside a cabin enters the light source to affect work of the light source is solved, the service life of the light source is prolonged, the problem that in the prior art, a lamp is prone to aging is solved, and meanwhile invisibility is good.

The utility model provides a kind of integrated stealth water column antenna, through the integration design of shell, water pump assembly, ground net plate and signal transmission component, significantly reduce antenna volume and promote stealth performance, shell columnar structure inlaying injection channel and isolation magnetic ring, realize the physical isolation of radio frequency signal and seawater, avoid the radar scattering problem caused by exposed metal parts of traditional shipborne antenna;Water pump assembly is directly connected with the lower side of shell, and forms radiator by injecting seawater, and after communication, pump can be stopped to realize antenna invisibility, signal transmission component and ground net plate are horizontally arranged on the upper end surface of shell, form compact plane layout, ground net plate arranged on the upper end surface of shell floats in sea level during use, only makes nozzle part above sea level, greatly enhances stealth performance, avoids the technical problem that water column antenna in the prior art is only applicable to ship platform use, use scene has great limitation, cannot meet the stealth demand.

The invention provides an active camouflage stealth system and method for a vehicle. The system comprises a central processing unit, a camera shooting unit and a lamp set controller which are connected with the central processing unit, and an RGB lamp set connected with the lamp set controller. Each RGB lamp set is composed of three lamps with the colors being red, green and blue, and the RGB lamp sets are fixed to a flexible net covering the top of the compartment and arranged into a rectangular array which is evenly distributed. The camera unit is used for shooting video images of the ground around the vehicle; and the central processing unit processes the video image to obtain a simulation image of the ground area under the vehicle, and controls the RGB lamp group based on the RGB pixel value of the simulation image, so that the vehicle image obtained by the reconnaissance equipment is approximate to the simulation image. The method has the advantages of novel hiding thought, simple and easy scheme implementation, good hiding effect and the like, and can effectively solve the problem of active optical band camouflage hiding of the vehicle in the road environment.

The utility model discloses a novel hovercraft which comprises a hovercraft body, a hovercraft bottom hovercraft apron and a propelling system. The hull bottom hover apron is arranged on the bottom surface of the hull, and a plurality of lift fans are arranged in the hull; the propelling system is arranged at the tail end of the top of the ship body and comprises an S-shaped air inlet channel and a thrust vector propelling engine. An air inlet of the S-bend air inlet channel is communicated with the external environment, and an air outlet of the S-bend air inlet channel is communicated with an air inlet of the thrust vector propulsion engine; the thrust vectoring propulsion engine comprises an engine body and a thrust vectoring nozzle which is communicated with an exhaust port of the engine body and has a thrust reversing function. Therefore, the jet pipe with the thrust vectoring function is used for replacing a control surface behind a propulsion fan of a traditional hovercraft, the aerodynamic efficiency is high, the response is rapid, and the hovercraft is flexible; and by combining a series of designs such as the S-shaped air inlet channel, exposed parts of the hovercraft are few, and the stealth performance is greatly improved.

The invention provides a tailless wide-speed-range aircraft based on a vortex wave effect and a control method thereof.The tailless wide-speed-range aircraft comprises an aircraft body, the aircraft body comprises an aircraft body and wings, the wings and the aircraft body form a wing-body fusion layout, the wings comprise inner wings and outer wings, the inner wings are provided with inner side elevators and outer side elevators, and the outer side elevators are provided with outer side elevators; the outer wing is provided with an aileron, a wing trailing edge resistance type rudder and a wing embedded resistance type rudder; a fuselage lift type rudder is arranged at the tail of the fuselage. According to the invention, the windward side shock wave and leeside vortex characteristics of the wing are optimized, and wide-speed-range lift force generation and wave drag reduction are realized. The radar reflection cross section is reduced by adopting the empennage-free layout, and the stealth performance is improved through the smooth wing body fusion design. The multi-control-surface cooperative control strategy solves the problem of lateral static instability of the tailless aircraft, and meanwhile, the wide-speed-range control requirement is met. The layout flexibility is improved, and the pneumatic control performance and the structural performance of the aircraft are optimized by functional partitioning of the inner wing, the outer wing and the control surface.

The invention provides an acoustic vector sensor 2D-DOA estimation method and system of any array structure, and relates to the array sensor direction finding technology. According to the method, the covariance matrix is obtained, characteristic decomposition is performed on the covariance matrix, the signal subspace is solved, rough estimation is performed on the two-dimensional DOA in the vector information according to the signal subspace by adopting the ESPRIT algorithm, and then phase compensation is performed on spatial ambiguity by utilizing the rough estimation result. The 2D-DOA accurate estimation of the acoustic vector sensor of any array structure is realized; the spatial layout of any array is realized by using the vector sensor, and the array element spacing of the sensor is not limited by half wavelength any more; according to the method, the information of a vector part is utilized, the information of a space phase is also utilized, the estimation precision is remarkably improved, spectral peak search and additional two-dimensional angle pairing calculation do not need to be carried out on a covariance matrix of a received signal, and the calculation complexity is remarkably reduced.

The invention relates to the technical field of electromagnetic scattering, in particular to a method for extracting the RCS characteristic of a supersonic target coated with a plasma sheath, and the method comprises the following steps: 1, building a simulation model of the supersonic target; 2, analyzing and testing the RCS characteristics of the supersonic target model; 3, establishing a single-layer plasma sheath model for the supersonic target model, and analyzing and testing the RCS characteristics of the single-layer plasma sheath model; 4, establishing a double-layer plasma sheath model for the supersonic target model, and analyzing and testing the RCS characteristics of the double-layer plasma sheath model; and step 5, comparing and analyzing the RCS characteristics extracted in the step 2, the step 3 and the step 4. According to the invention, the RCS characteristics of the supersonic target coated by the plasma sheath can be comprehensively and accurately detected and analyzed. Through the method, the stealth performance of the supersonic target and the monitoring and striking capability of a defense system can be accurately evaluated.

The application belongs to the technical field of skin materials, and particularly relates to an X-waveband stealth skin, a preparation method and application thereof. The preparation method of the X-waveband stealth skin comprises the following steps: (1) preparing a modified epoxy resin system; (2) laying a carbon fiber mixture to obtain a carbon fiber mixture film layer; (3) laying a conductive mixture on the surface of the carbon fiber mixture film layer to obtain a conductive mixture film layer; (4) laying a wave-absorbing mixture on the surface of the conductive mixture film layer to obtain a wave-absorbing mixture film layer; (5) laying a wave-transmitting mixture on the surface of the wave-absorbing mixture film layer to obtain a skin material; and (6) vacuumizing and heating and curing the skin material to obtain an X-waveband stealth lightning-proof skin. The X-waveband stealth skin has excellent stealth performance and lightning-proof capability, and has a higher mechanical performance retention rate in an ultralow-temperature environment.