Passive sea clutter equivalent simulation board and method

Abstract

The invention discloses a passive sea clutter equivalent simulation board and method, the passive sea clutter equivalent simulation board comprises a monomer simulation board, the monomer simulation board comprises a surface water bag layer and a bottom air bag layer, the surface water bag layer is mounted on the bottom air bag layer in an attached manner, the surface water bag layer is provided with a water inlet and a water outlet, and the surface water bag layer is filled with modulated seawater; the bottom air bag layer is provided with an air inlet valve, an exhaust valve and a safety valve and is filled with air, the surface water bag layer simulates sea surface clutter scattering, and the bottom air bag layer simulates the shape of sea waves. A double-layer design scheme based on the air bag and the water bag is provided, the air bag structure is used for supporting the water bag structure, the air bag structure and the water bag structure are attached in a coplanar mode to completely support the water bag structure, and the water bag structure does not deform. The water bag is filled with formula seawater and is used for simulating the characteristics of seawater, so that the reflector structure realizes the characteristics of real mountain and real water, and the problem that sea clutter physical simulation is inaccurate and inconvenient is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of sea clutter simulation, and in particular relates to a passive sea clutter equivalent simulation board and a method. Background Art

[0002] Sea surface background clutter is one of the main factors that affect the target detection performance of marine radar. Its physical mechanism is complex, with many influencing factors and significant non-Gaussian and non-stationary characteristics. Therefore, the study of sea clutter characteristics is an extremely complex system engineering. Whether in military or civilian aspects, it is increasingly important for marine radar to quickly and reliably detect targets at sea. However, the working environment faced by radar is complex and changeable. In addition to the target echo of interest, the echo signal it receives also contains noise, interference, sea clutter, etc.

[0003] Among the above factors, due to the high power level of sea surface background environmental clutter, and its significant non-Gaussian and non-stationary characteristics, coupled with the complexity and variability of its influencing factors, sea clutter has become one of the main constraints affecting detection performance. Therefore, starting from the needs of target detection, conducting research on sea clutter characteristics cognition, mastering the sea clutter change trend and establishing a sea clutter model are the basic premise and foundation for effectively improving and innovating sea clutter simulation methods, weakening the adverse effects of sea clutter, and achieving improved detection performance.

[0004] However, there is currently little sea clutter test data, the confidence of the sea clutter simulation model is insufficient, the physical simulation of sea clutter is not accurate enough, and the physical simulation means are insufficient and not convenient enough. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem that the physical simulation of sea clutter is inaccurate and inconvenient, and a passive sea clutter equivalent simulation board and method are proposed.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: A passive sea clutter equivalent simulation board comprises a single simulation board, wherein the single simulation board comprises a surface water bag layer and a bottom air bag layer, wherein the surface water bag layer is fitted and installed on the top of the bottom air bag layer, wherein the surface water bag layer is provided with a water inlet and outlet, wherein the surface water bag layer is perfused with regulated seawater, wherein the bottom air bag layer is provided with an air inlet valve, an air exhaust valve and a safety valve, wherein the bottom air bag layer is perfused with air, wherein the surface water bag layer simulates the scattering of sea clutter, and wherein the bottom air bag layer simulates the shape of sea waves.

[0007] Furthermore, the bottom airbag layer is provided with buckles, and a plurality of single simulation plates are spliced ​​into an overall wave model through the buckles, and the buckles are plastic buckles.

[0008] Furthermore, the surface water bag layers between the individual simulation plates of the overall wave model are seamlessly overlapped.

[0009] Furthermore, at least two air pressure valves are arranged at the wave top of the surface water bag layer, and two water valves are arranged at the lower parts of both sides of the surface water bag layer.

[0010] Furthermore, an exhaust valve is arranged at the highest point of each wave in each monomer simulation plate of the overall wave model, and an inlet valve is arranged at the midpoint and the lowest point respectively.

[0011] Furthermore, the surface water bag layer and the bottom air bag layer are snap-connected.

[0012] Furthermore, the surface water bag layer is made of rubber cloth, and the bottom air bag layer is made of brushed cloth.

[0013] An equivalent simulation method for a passive sea clutter equivalent simulation board comprises the following steps: The sea clutter echo data is obtained by measuring the sea surface background environment echo test; the sea surface equivalent simulation is performed using the sea clutter echo data to obtain the simulated sea surface; The seawater data is obtained by seawater test measurement, and the seawater data is used to perform seawater equivalent simulation to obtain modulated seawater; An equivalent simulation board is obtained by physically developing the simulated sea surface, and modulated seawater is poured into the equivalent simulation board to obtain a passive sea clutter equivalent simulation board; The method of obtaining sea clutter echo data by measuring the sea surface background environment echo test and performing sea surface equivalent simulation using the sea clutter echo data to obtain a simulated sea surface comprises the following steps: The sea surface parameters are set based on the sea clutter echo data to construct a sea surface model based on the wave power spectrum; A 2D parameter-adjustable rough sea surface model is constructed based on the sea surface model based on the wave power spectrum; The sea clutter simulation model is obtained by optimizing the 2D parameter-adjustable rough sea surface model; The sea clutter simulation model is used to generate a simulated sea surface.

[0014] Furthermore, the setting of sea surface parameters based on sea clutter echo data to construct a sea surface model based on sea wave power spectrum comprises the following steps: The sea level is generated based on the sea clutter echo data using the sea surface generation algorithm, the frequency domain spectrum of the sea level is calculated, the frequency domain data is converted into wave number domain data through Fourier transform, and the diffusion mode of the sea surface waves is set to obtain the sea surface model based on the wave power spectrum; The method of constructing a 2D parameter-adjustable rough sea surface model based on a sea surface model based on a wave power spectrum is specifically as follows: After introducing random variables into the sea surface model based on the wave power spectrum to simulate the randomness of the sea surface, the sea surface model after randomization is subjected to inverse Fourier transform to obtain a 2D parameter-adjustable rough sea surface model, wherein the parameters of the 2D parameter-adjustable rough sea surface model include the wave series and the diffusion mode; The method of optimizing the 2D parameter-adjustable rough sea surface model to obtain a sea clutter simulation model comprises the following steps: The 2D parameter-adjustable rough sea surface model is converted into a sea surface data model that can be imported into 3D modeling software, a sea clutter simulation software interface is constructed, the sea surface data model is optimized according to the actual situation of the sea area, and a sea clutter simulation model is simulated and generated in the sea clutter simulation software interface.

[0015] Furthermore, the seawater data is obtained by seawater testing and measurement, and the seawater data is used to perform seawater equivalent simulation to obtain modulated seawater, which includes the following steps: Sampling seawater in the target sea area to obtain sampled seawater, measuring seawater parameters of the sampled seawater, and recording and counting the seawater parameters of the target sea area to obtain seawater data; the seawater parameters include conductivity, TDS, temperature and salinity of the seawater; The median of each seawater parameter in the seawater data is taken as the target parameter of the seawater equivalent ratio to mix the seawater, and water and sea salt are added to mix the seawater according to the salinity parameter of the target sea area to obtain the mixed seawater; The salinity, conductivity and temperature of the prepared seawater are measured. If the salinity, conductivity and temperature of the prepared seawater are within the statistical range of the seawater parameters of the target sea area, the seawater equivalent ratio is met and the modulated seawater is obtained.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The invention proposes a passive sea clutter equivalent simulation board, which proposes a double-layer design scheme based on airbags and water bags. The airbag structure is used to support the water bag structure. The airbag structure and the water bag structure are coplanarly attached to fully support the water bag structure, so that the water bag structure does not deform. The water bag is filled with formulated seawater to simulate the characteristics of seawater, so that the reflector structure can achieve the characteristics of real mountains and real water. Through the steps of model segmentation, material slicing, material processing, etc., a simulation board with good equivalent effect of simulating the shape of waves and the sea surface environment can be developed, which solves the problem of inaccurate and inconvenient physical simulation of sea clutter.

[0017] Furthermore, the sea clutter equivalent simulation board material has good air tightness, fire resistance, mildew resistance, high tensile strength, safety and environmental protection, stable structure, long service life, and conforms to the scientific concept of saving economic costs and not causing environmental pollution.

[0018] The invention proposes an equivalent simulation method of a passive sea clutter equivalent simulation board, explores the characteristic law of the basic characteristic parameters of the sea surface background, establishes a sea surface model, and develops a sea clutter equivalent simulation board to simulate the sea clutter environment, which can construct actual scenes such as sea surface background interference in a real environment. In practical applications, the real wave shape and sea clutter environment can be simulated, and the target detection performance of marine radar, the recognition of sea clutter characteristics, the simulation of the sea surface environment, and the optimization of the target detection algorithm are significantly improved.

[0019] Furthermore, the sea clutter simulation model adopts a modeling technology that combines the basic model with the measured data optimization, which can well simulate the sea surface environment of level 1 to level 5. By analyzing the formation mechanism and electromagnetic characteristics of sea clutter, it can simulate the clutter scattering and interference performance of the sea surface, and solve the problems of poor clutter simulation accuracy and insufficient detection performance of marine radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are for explanation purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings: Figure 1 The figure is a schematic diagram of a passive sea clutter equivalent simulation board of the present invention.

[0021] Figure 2 The figure is a schematic diagram of a single simulation board of a passive sea clutter equivalent simulation board of the present invention.

[0022] Figure 3 This is a physical picture of a single simulation board of a passive sea clutter equivalent simulation board in an embodiment of the present invention.

[0023] Figure 4 This is an overall splicing connection diagram of a passive sea clutter equivalent simulation board in an embodiment of the present invention.

[0024] Figure 5 The present invention is a flow chart of an equivalent simulation method of a passive sea clutter equivalent simulation board.

[0025] Figure 6 The figure is an overall flow chart of an equivalent simulation method of a passive sea clutter equivalent simulation board in an embodiment of the present invention.

[0026] Figure 7 The invention discloses a seawater equivalent flow chart for modulating an equivalent simulation method of a passive sea clutter equivalent simulation board.

[0027] Figure 8 The present invention provides an equivalent sea surface simulation diagram of an equivalent simulation method of a passive sea clutter equivalent simulation board.

[0028] Fig. 9 It is an equivalent simulation diagram of an equivalent simulation method of a passive sea clutter equivalent simulation board of the present invention.

[0029] Fig.10 The present invention is a flowchart of the process for producing a passive sea clutter equivalent simulation board according to an embodiment of the present invention.

[0030] Among them, 1 is the surface water bag layer, 11 is the water inlet and outlet, 2 is the bottom air bag layer, 21 is the air inlet valve, 22 is the exhaust valve, and 23 is the safety valve. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] Embodiment 1 See also Figure 1 , Figure 2 and Figure 3 A passive sea clutter equivalent simulation board includes a single simulation board, the single simulation board includes a surface water bag layer 1 and a bottom air bag layer 2, the surface water bag layer 1 is fitted on the bottom air bag layer 2, the surface water bag layer 1 is provided with a water inlet and outlet 11, the surface water bag layer 1 is infused with regulated seawater, the bottom air bag layer 2 is provided with an air inlet valve 21, an exhaust valve 22 and a safety valve 23, the bottom air bag layer 2 is infused with air, the surface water bag layer 1 simulates sea clutter scattering, and the bottom air bag layer 2 simulates the shape of waves.

[0036] See also Figure 4 , buckles are set on the bottom airbag layer 2, and several monomer simulation boards are spliced ​​into an overall wave model through buckles, and the buckles are made of plastic buckles. The surface water bag layer 1 is seamlessly overlapped between the monomer simulation boards of the overall wave model. At least two air pressure valves are set at the wave top of the surface water bag layer 1, and two water valves are set at the low points on both sides of the surface water bag layer 1. An exhaust valve 22 is set at the highest point of each wave in each monomer simulation board of the overall wave model, and an inlet valve is set at the midpoint and the lowest point. The surface water bag layer 1 is connected with the bottom airbag layer 2 by snap buckles. The surface water bag layer 1 is made of rubber cloth, and the bottom airbag layer 2 is made of brushed cloth.

[0037] This embodiment realizes the simulation of waves and clutter of different sea areas and different levels. Based on the advantages of the simulation board such as stable structure, good consistency of electromagnetic simulation and low cost, it can be laid over a large area, carry out sea clutter background tests under different conditions, obtain electromagnetic echo data, and conduct sea clutter analysis and experiments.

[0038] Embodiment 2 See also Figure 5 and Figure 6 , an equivalent simulation method of a passive sea clutter equivalent simulation board, comprising the following steps: See also Figure 8 and Fig. 9 , sea clutter echo data is obtained by measuring the sea surface background environment echo test; sea surface equivalent simulation is performed using the sea clutter echo data to obtain a simulated sea surface; See also Figure 7 , seawater data is obtained through seawater test measurement, and seawater equivalent simulation is performed using the seawater data to obtain modulated seawater; An equivalent simulation board is obtained by physically developing the simulated sea surface, and modulated seawater is poured into the equivalent simulation board to obtain a passive sea clutter equivalent simulation board; The sea clutter echo data is obtained by measuring the sea surface background environment echo test, and the sea surface equivalent simulation is performed using the sea clutter echo data to obtain the simulated sea surface, including the following steps: The sea surface parameters are set based on the sea clutter echo data to construct a sea surface model based on the wave power spectrum; A 2D parameter-adjustable rough sea surface model is constructed based on the sea surface model based on the wave power spectrum; The sea clutter simulation model is obtained by optimizing the 2D parameter-adjustable rough sea surface model; The sea clutter simulation model is used to generate a simulated sea surface.

[0039] Setting sea surface parameters based on sea clutter echo data to construct a sea surface model based on wave power spectrum includes the following steps: The sea level is generated based on the sea clutter echo data using the sea surface generation algorithm, the frequency domain spectrum of the sea level is calculated, the frequency domain data is converted into wave number domain data through Fourier transform, and the diffusion mode of the sea surface waves is set to obtain the sea surface model based on the wave power spectrum; According to the sea surface model based on the wave power spectrum, a 2D parameter-adjustable rough sea surface model is constructed, specifically: After introducing random variables into the sea surface model based on the wave power spectrum to simulate the randomness of the sea surface, the inverse Fourier transform is used to obtain a 2D parameter-adjustable rough sea surface model for the randomized sea surface model. The parameters of the 2D parameter-adjustable rough sea surface model include the wave series and diffusion mode. The sea clutter simulation model is obtained by optimizing the 2D parameter-adjustable rough sea surface model, including the following steps: The 2D parameter-adjustable rough sea surface model is converted into a sea surface data model that can be imported into 3D modeling software, a sea clutter simulation software interface is constructed, the sea surface data model is optimized according to the actual situation of the sea area, and a sea clutter simulation model is simulated and generated in the sea clutter simulation software interface.

[0040] The seawater data is obtained by seawater test measurement, and the seawater data is used to perform seawater equivalent simulation to obtain modulated seawater, including the following steps: Sampling seawater in the target sea area to obtain sampled seawater, measuring seawater parameters of the sampled seawater, and recording and counting the seawater parameters of the target sea area to obtain seawater data; the seawater parameters include conductivity, TDS, temperature and salinity of seawater; The median of each seawater parameter in the seawater data is taken as the target parameter of the seawater equivalent ratio to mix the seawater, and water and sea salt are added to mix the seawater according to the salinity parameter of the target sea area to obtain the mixed seawater; The salinity, conductivity and temperature of the prepared seawater are measured. If the salinity, conductivity and temperature of the prepared seawater are within the statistical range of the seawater parameters of the target sea area, the seawater equivalent ratio is met and the modulated seawater is obtained.

[0041] According to the high-precision sea clutter simulation model, the split unit structure and the long straight structure are combined to form the sea clutter surface. The optimal fitting seawater solution obtained by seawater test data is used to process the surface-attributed aerated seawater composite structure to simulate the actual sea conditions. It is used for wave and clutter simulation, which can effectively simulate the shape of the waves and the electromagnetic characteristics of the sea surface. Based on the sea clutter equivalent simulation board, sea clutter background tests under different conditions can be carried out, electromagnetic echo data can be obtained, and sea clutter analysis and test work can be carried out.

[0042] Embodiment 3 A passive sea clutter equivalent simulation board mainly includes a water bag layer and a bottom air bag. The bottom air bag is used for structural support to simulate the shape of sea waves, and the water bag layer is used to simulate the clutter scattering of the sea surface.

[0043] The following is a detailed description of the specific development process of a passive sea clutter equivalent simulation board, see Figure 6 The development method includes three parts: sea surface digital model building, sea surface parameter measurement, and sea clutter equivalent simulation board development.

[0044] Through the study and comparison of sea surface digital models such as geometric modeling, physical modeling, and wave spectrum modeling, a sea surface model with relatively good simulation effect is selected; and combined with the study of the basic characteristic parameters of sea clutter (including wave parameters, seawater color, conductivity and other characteristic parameters of each sea area), the sea surface digital model is optimized, and multiple groups of simulation data of the sea surface background environment are generated. A group with a complete wave cycle and rich and realistic wave shapes is selected as needed for physical processing of the simulation board; and the material selection and processing technology are studied, and finally the brushed cloth material with high structural stability, good simulation effect, safety, environmental protection and durability is selected for research and development, and the processing technology is selected and optimized to ensure that the sea clutter equivalent simulation board device can well simulate the relevant characteristics of real sea surface waves and clutter environment.

[0045] The sea surface parameter measurement includes sea clutter test and seawater parameter test. The sea surface background environment echo test is to mount the receiver and transmitter on the drone, quickly measure through the reflector, obtain the stray echo data of the sea surface, and obtain the simulation effect of the sea surface background environment based on the data. Seawater testing mainly includes electromagnetic testing and chemical testing. The electromagnetic test measures the conductivity of seawater through the conductivity meter and obtains the corresponding electromagnetic properties such as dielectric constant. The chemical test measures the salinity of seawater through the corresponding chemical instrument, laying the foundation for the subsequent equivalent simulation of seawater.

[0046] Sea clutter data analysis and modeling mainly include modeling methods based on wave spectrum, modeling methods based on physical models, and modeling methods based on three-dimensional shape data. This technology generates an equivalent sea surface background environment model through a modeling method based on three-dimensional shape data, and uses the equivalent sea surface generated by a modeling method based on a physical model as a control. The two verify each other and complement each other. The simulation data obtained by the classic sea surface model generated by the modeling method based on the wave spectrum is compared with the measured data, and the generated equivalent sea surface is optimized to provide accurate and reliable model support for the development of the final sea clutter equivalent simulation board device.

[0047] The development of sea clutter equivalent plate is mainly realized through equivalent simulation of seawater and equivalent simulation of sea surface. By using the measured seawater data, after analysis, the equivalent generation method and proportion model of seawater are obtained, and finally processed. The realization of equivalent simulation of sea surface can directly adopt the sea surface model mentioned above, and use inflatable-seawater type materials to generate the sea surface. This method has strong operability, strong replicability, and is easy to carry and transport.

[0048] See also Figure 7 , the following is a further description of the seawater equivalent simulation development: The equivalent simulation of seawater mainly simulates the salinity, conductivity and temperature of seawater. Multiple seawater sampling is carried out in the target sea area, and the conductivity, TDS and temperature of seawater are measured using a portable conductivity meter; the salinity of seawater is measured using a salinity meter to obtain various seawater parameters in the target sea area.

[0049] Record and count the various seawater parameters of the target sea area, take the median as the target parameter of the seawater equivalent ratio to prepare the seawater. Use a stirring tank to add water and sea salt at the appropriate temperature according to the salinity parameters of the target sea area to prepare the seawater, and then measure the salinity, conductivity and temperature of the prepared seawater. For the prepared seawater, if its various parameters are within the range of multiple test parameters of real seawater, it meets the seawater equivalent ratio. The solution can be injected into the water bag layer of the sea clutter equivalent simulation board to complete the seawater equivalent simulation research and development.

[0050] The following is a further detailed description of the base airbag material research process: The research on airbag materials mainly considers the working performance of airbag materials such as air tightness, fire resistance, structural stability, and safety performance such as tensile strength and tear strength. Specifically, the selection of simulation board base materials must meet the safety working performance of airbag materials with air tightness ≥ Level 3, fire resistance meeting Class B standard, tensile strength ≥ 2200N / 5cm, tear strength ≥ 280N / 5cm, and material strength ≥ Level 3; after one inflation molding, the appearance of the simulation board base airbag must be maintained for no less than 7 days.

[0051] Based on the performance and safety performance indicators of the base airbag material, and considering the goal of simulating the wave shape and electromagnetic characteristics of the sea clutter equivalent simulation board, rubber cloth is selected as the base airbag material of the sea clutter equivalent simulation board. Rubber material is a highly elastic polymer material with reversible deformation. It is a completely amorphous polymer with elasticity, airtightness and insulation. It is a molecular compound with high airtightness. Rubber materials have very good effects in airtightness, anti-aging performance, weather resistance, sunlight resistance, friction resistance and mildew resistance. At the same time, they have good electrical insulation performance and good chemical resistance. They are currently the best airtight material and are suitable for use as airbag materials.

[0052] Water bladder layer material research The following is a further detailed description of the water bladder layer material research process: As the material of the water bag layer, it needs to have excellent sealing, elasticity and dimensional stability; the color also needs to be close to the original color of the waves. Specifically, it needs to meet the following requirements: Water bag layer thickness: 3.5±1.55cm; PVC film wave transmittance ≥-6dB (≤60GHz); material weight ≤3kg / m2; tensile strength ≥2200N / 5cm; tear strength ≥280N / 5cm; adhesion strength ≥100N; fiber density ≥23 lines / inch; The wire drawing cloth adopts 3D weaving technology and is a three-dimensional material. It is woven by upper and lower membrane materials and middle wire drawing. The wire drawing can also be replaced by drawing strips, which has the characteristics of stable size, smooth surface and good resilience. The wire drawing cloth has good structural stability and high bearing capacity. The wire drawing strength inside the structure is high and the rigidity is large. It can effectively restrain the inflation and expansion deformation of the structure. The working pressure of most space wire drawing cloth products can reach 100kPa, while the working pressure range of general air-bearing structure and ETFE air pillow structure is only 0.25-20kPa. The inflatable flat plate structure is not prone to membrane failure under external loads and has high safety in use. At the same time, the upper and lower membrane materials of the wire drawing cloth are constrained by wire drawing and have high flatness. The structural shape can be adjusted by changing the distribution density of the wire drawing. This feature makes the structure have a higher bearing capacity than the traditional inflatable membrane structure and can meet the wave simulation requirements of the water bag layer of the sea clutter simulation board.

[0053] Considering the above characteristics and the economic factor of cost saving, RAL 5020 ocean blue double-layer brushed cloth is selected as the material of the water bladder layer. The water bladder layer is made of double-sided fiber cloth filled with seawater simulation liquid, and the flow of seawater is restrained by brushed fibers to form the shape of waves.

[0054] See also Figure 8 and Fig. 9 , the digital model generation and conversion are further described in detail below: The core idea of ​​generating the digital model of the sea surface is as follows: first, generate the sea level and calculate the sea spectrum in the frequency domain, including the PM sea spectrum, the JS sea spectrum, and related parameters such as the peak frequency; convert the clutter frequency domain into the wave number domain through Fourier transform; since the real sea surface requires a symmetrical spectrum domain of wave numbers; therefore, where necessary, additional calculations are required to ensure that the expansion matrix is ​​indeed symmetrical; set diffusion (cosine square diffusion, Mitsuyasu diffusion) as needed; under the setting of the above sea surface parameters, the power spectrum and the sea surface model based on the power spectrum can be obtained; then introduce random variables, and obtain the 2D rough sea surface through inverse Fourier transform; finally, through the interface construction, realize the sea surface model that can adjust the parameters such as the wave series and diffusion mode. The schematic diagram of the sea clutter simulation generated according to the sea surface model is as follows.

[0055] Since the sea surface model cannot be directly used in the physical development of the sea clutter simulation board device, it is necessary to convert the sea surface model into surface data and then into an obj data model that can be imported into 3D modeling software; Use Matlab to build a sea clutter simulation software interface, which is convenient for directly selecting different wave levels, sea spectra and diffusion conditions to simulate different sea surface models; The model is optimized according to the actual situation of the sea area, and finally a sea clutter simulation model that can be applied to the development of actual simulation board devices is generated. The three-dimensional schematic diagram of the model simulation is as follows. The applicable simulation board materials and processes are selected according to the model; See also Fig.10 , the following is a further detailed description of the development process of the simulation board: The process development and design of the sea clutter equivalent simulation board is a comprehensive process, which involves all aspects from preliminary design to final product completion. Fig.10 As shown. First, it is necessary to determine the specific design plan according to the application requirements and process standards, and produce design drawings, then select materials and pre-treat them, process, manufacture and assemble the treated materials, and finally test and adjust the completed simulation device to complete the process development. The simulation board device adopts a layered structure as a whole. The base air bag and surface water bag layer of the model are made of brushed cloth and rubber cloth respectively, so that the model can simulate the effect of real waves under visible light. The simulation board device is a disposable inflatable model. It is composed of multiple independent units that are quickly plugged into a complete structure. The water bag layer of each unit can be flushed and drained at the same time, which is convenient for the rapid erection and withdrawal of the device and easy to store and transport.

[0056] The overall shape of the sea clutter equivalent simulation board is determined according to the index requirements and scene usage, and it will be divided into modules of several sizes and then assembled according to the specific usage scene size. Figure 3 .

[0057] The selected 3D model diagram is optimized into a design drawing that can be processed and implemented, including the three-dimensional structure of the sea clutter equivalent simulation board, the air inlet, the water inlet and outlet (the water inlet and outlet are used for water inlet or water outlet), the connection buckles and other position designs.

[0058] According to the index requirements, the materials selected are brushed cloth and rubber cloth to meet the requirements of various indicators.

[0059] Refine the preliminary design into detailed construction drawings, including the dimensions of each part, connection methods, material usage, etc.

[0060] Use Rhino or other CAD design software to create a 3D model to more intuitively display and check the design.

[0061] Conduct internal review of drawings to ensure the accuracy and feasibility of the design.

[0062] According to the drawings, determine the required PVC materials, heat-sealing glue, sewing thread, etc.

[0063] Wash and dry the materials to ensure they are free of stains and dust.

[0064] Use CNC cutting machine to cut materials as needed.

[0065] According to the drawings, the various materials are heat-sealed and sewn using sewing machines, needle machines and hot-melt adhesive to form the various components of the sea clutter equivalent simulation board.

[0066] Perform quality checks on components to ensure there are no leaks or damage.

[0067] Assemble the components according to the instructions on the drawing to form a complete sea clutter equivalent simulation board device.

[0068] Use a fan to inflate the sea clutter equivalent simulation board and check its inflation speed and stability.

[0069] Pressure test the sea clutter equivalent simulation board to ensure it can withstand the predetermined pressure without leaking.

[0070] According to the test results, necessary adjustments and optimizations are made to the sea clutter equivalent simulation board.

[0071] Cut the PVC mesh cloth (including printed and laminated PVC mesh cloth) or TPU film into the required shape according to the design drawing. The cutting tools, process and cutting standards of the cutting process need to be explained; The cut PVC mesh fabric and other parts are assembled using an industrial sewing machine. The tools and materials, sewing techniques and sewing sequence required for sewing need to be explained; The spliced ​​and sewn parts are heat-sealed and reinforced using a heat sealing machine.

[0072] Sea clutter equivalent simulation board inspection process: inspect the appearance and tightness of the assembled products.

[0073] Place the sea clutter equivalent simulation board on a flat mat, spread it out flatly according to the terrain requirements, and fix the bottom of the simulation board with fixed ropes and anchors; Use plastic buckles prefabricated on the edges of the base airbag and water bag layer to connect the water bag layer and the airbag, as well as each block unit, to complete the assembly of the overall structure; Find the air inlet of the bottom airbag, connect it to the air outlet of the high-pressure air pump, tie up the fan port, and tie up the spare air inlet; connect the high-pressure air pump to the power supply to fully deploy the bottom airbag.

[0074] The seawater is proportioned according to the conductivity, salinity and temperature data of the target sea area obtained by the test, that is, industrial coarse salt and pure water are added to the stirring tank for sufficient stirring, and then the conductivity, salinity and temperature parameters of the proportioned seawater are measured using the same method to make the two data basically consistent, and the proportioned seawater is injected into the water bag layer of the sea clutter equivalent simulation board through the water supply device; Check that all buckles are fastened, the water bag layer is not leaking, and the air bag layer is not leaking. The simulation board device is set up and can be used in the required scenarios. The size of the simulation board device and the level of simulated waves (optional 3~6 levels) can be selected according to the actual needs of the usage scenario. The simulation board consists of a water bag layer and a base air bag. The water bag layer is located above the base air bag structure. Figure 1 As shown. The water bag layer is equipped with a water inlet and a water outlet, and the base air bag is designed with an air inlet valve, an exhaust valve and a safety valve. When in use, an air pump and a water pump are required to inject air and conditioned seawater into the base air bag and the water bag layer respectively.

[0075] The device is composed of multiple single simulation panels spliced ​​together to form an overall wave model, as shown in Figure 4.

[0076] In order to ensure good simulation effect of the device and facilitate the installation and use of the simulation board, the sea clutter equivalent simulation board device must meet the following requirements during the actual preparation process: 1) The thickness of the water cyst layer is 3.5±1.55cm; 2) The minimum height of the base airbag trough is ≥ 0.5m; 3) Single module unit size ≥ 20m 2 ; 4) The sea clutter equivalent simulation board is processed according to the above digital three-dimensional simulation data model, and the manufacturing error is ±3cm; 5) The individual independent units are quickly connected to form a complete whole through the plastic buckles of the base airbag, which can facilitate the rapid erection and withdrawal of the simulation board, and is easy to store and transport; 6) The sea clutter equivalent simulation board needs to be seamlessly connected, and the water bag layers are fixed. There can be overlaps, and the overlap size of the water bag layers is 0.5cm~2cm; 7) The units and the water bag layer and the bottom air bag are connected by buckles. Plastic buckles must be used. The number of plastic buckles at each corner connection of the sea clutter equivalent simulation board is not less than 3. The size of the plastic buckle is self-determined. Plastic buckles are prohibited from having metal accessories; 8) At least two air pressure valves are installed at the wave top of the water bag layer of each simulation board, and two water valves are installed at the lower part of both sides of the water bag layer; 9) The spatial distribution water layer has the same shape as the upper surface of the support part and fits in with it. According to the key parts of the shape: wave crests, wave valleys, and the edges of the block units, they need to be aligned and then stretched to form; 10) An exhaust valve is set at the highest point of each wave of each unit; an inlet valve is added at the midpoint and the lowest point respectively; 11) The bottom airbag part is equipped with pressure relief valve and inflation valve, such as Figure 2 As shown; 12) Add D-shaped buckle points to important locations of each part of the overall product to facilitate fixation and use; 13) The two-layer structure of the wave (inflatable layer and water bag layer) can be connected into one by buckles, and the distance between the contact surface edges is less than 1.5cm; 14) Independent slices are cut for local peaks and valleys. The number of independent slices for each peak higher than 1.5m must be ≥ 3 to ensure the shape of the wave crest; The sea clutter equivalent simulation board is based on a high-precision sea clutter simulation model. It uses a split unit structure and a long straight structure to combine the sea clutter surface. It uses the best fitting seawater solution obtained from seawater test data to process the surface-attributed aerated seawater composite structure to simulate actual sea conditions.

[0077] Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

[0078] The above content is a further detailed description of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, they can also make several simple deductions or substitutions, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A passive sea clutter equivalent simulation board, characterized in that: The invention comprises a single body simulation board, wherein the single body simulation board comprises a surface water bag layer (1) and a bottom air bag layer (2), wherein the surface water bag layer (1) is mounted on the top of the bottom air bag layer (2), wherein the surface water bag layer (1) is provided with a water inlet and outlet (11), wherein the surface water bag layer (1) is filled with conditioned seawater, wherein the bottom air bag layer (2) is provided with an air inlet valve (21), an air outlet valve (22) and a safety valve (23), wherein the bottom air bag layer (2) is filled with air, wherein the surface water bag layer (1) simulates the scattering of sea surface clutter, and wherein the bottom air bag layer (2) simulates the shape of sea waves.

2. A passive sea clutter equivalent simulation board according to claim 1, characterized in that: The bottom airbag layer (2) is provided with buckles, and a plurality of single simulation plates are spliced ​​into an overall wave model through the buckles, and the buckles are made of plastic.

3. A passive sea clutter equivalent simulation board according to claim 2, characterized in that: The surface water bag layers (1) between the individual simulation plates of the overall wave model are seamlessly overlapped.

4. The passive sea clutter equivalent simulation board according to claim 1, characterized in that: At least two air pressure valves are arranged at the wave top of the surface water bag layer (1), and two water valves are arranged at the lower parts of both sides of the surface water bag layer (1).

5. The passive sea clutter equivalent simulation board according to claim 1, characterized in that: An exhaust valve (22) is provided at the highest point of each wave in each single simulation plate of the overall ocean wave model, and an inlet valve is provided at the midpoint and the lowest point respectively.

6. The passive sea clutter equivalent simulation board according to claim 1, characterized in that: The surface water bag layer (1) and the bottom air bag layer (2) are snap-connected.

7. The passive sea clutter equivalent simulation board according to claim 1, characterized in that: The surface water bag layer (1) is made of rubber cloth, and the bottom air bag layer (2) is made of brushed cloth.

8. An equivalent simulation method for a passive sea clutter equivalent simulation board, characterized in that: The steps include: The sea clutter echo data is obtained by measuring the sea surface background environment echo test; the sea surface equivalent simulation is performed using the sea clutter echo data to obtain the simulated sea surface; The seawater data is obtained by seawater test measurement, and the seawater data is used to perform seawater equivalent simulation to obtain modulated seawater; An equivalent simulation board is obtained by physically developing the simulated sea surface, and modulated seawater is poured into the equivalent simulation board to obtain a passive sea clutter equivalent simulation board; The method of obtaining sea clutter echo data by measuring the sea surface background environment echo test and performing sea surface equivalent simulation using the sea clutter echo data to obtain a simulated sea surface comprises the following steps: The sea surface parameters are set based on the sea clutter echo data to construct a sea surface model based on the wave power spectrum; A 2D parameter-adjustable rough sea surface model is constructed based on the sea surface model based on the wave power spectrum; The sea clutter simulation model is obtained by optimizing the 2D parameter-adjustable rough sea surface model; The sea clutter simulation model is used to generate a simulated sea surface.

9. The equivalent simulation method of a passive sea clutter equivalent simulation board according to claim 8, characterized in that: The method of setting sea surface parameters based on sea clutter echo data and constructing a sea surface model based on sea wave power spectrum comprises the following steps: The sea level is generated based on the sea clutter echo data using the sea surface generation algorithm, the frequency domain spectrum of the sea level is calculated, the frequency domain data is converted into wave number domain data through Fourier transform, and the diffusion mode of the sea surface waves is set to obtain the sea surface model based on the wave power spectrum; The method of constructing a 2D parameter-adjustable rough sea surface model based on a sea surface model based on a wave power spectrum is specifically as follows: After introducing random variables into the sea surface model based on the wave power spectrum to simulate the randomness of the sea surface, the sea surface model after randomization is subjected to inverse Fourier transform to obtain a 2D parameter-adjustable rough sea surface model, wherein the parameters of the 2D parameter-adjustable rough sea surface model include the wave series and the diffusion mode; The method of optimizing the 2D parameter-adjustable rough sea surface model to obtain a sea clutter simulation model comprises the following steps: The 2D parameter-adjustable rough sea surface model is converted into a sea surface data model that can be imported into 3D modeling software, a sea clutter simulation software interface is constructed, the sea surface data model is optimized according to the actual situation of the sea area, and a sea clutter simulation model is simulated and generated in the sea clutter simulation software interface.

10. The equivalent simulation method of a passive sea clutter equivalent simulation board according to claim 8, characterized in that: The method of obtaining seawater data through seawater testing and measuring, and using the seawater data to perform seawater equivalent simulation to obtain modulated seawater includes the following steps: Sampling seawater in the target sea area to obtain sampled seawater, measuring seawater parameters of the sampled seawater, and recording and counting the seawater parameters of the target sea area to obtain seawater data; the seawater parameters include conductivity, TDS, temperature and salinity of the seawater; The median of each seawater parameter in the seawater data is taken as the target parameter of the seawater equivalent ratio to mix the seawater, and water and sea salt are added to mix the seawater according to the salinity parameter of the target sea area to obtain the mixed seawater; The salinity, conductivity and temperature of the prepared seawater are measured. If the salinity, conductivity and temperature of the prepared seawater are within the statistical range of the seawater parameters of the target sea area, the seawater equivalent ratio is met and the modulated seawater is obtained.

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