Method for extracting RCS (radar cross section) characteristics of supersonic target coated with plasma sheath
By establishing a simulation model of supersonic targets in FEKO software and adding a plasma sheath layer, the problem of difficulty in extracting the RCS characteristics of supersonic targets in the prior art is solved, and accurate RCS characteristics extraction in the terahertz band is achieved, and the stealth performance and monitoring accuracy of the target are improved.
Patent Information
- Application Number
- CN202411877909.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-03-14
AI Technical Summary
The prior art is difficult to effectively extract the radar scattering cross-sectional area (RCS) characteristics of the plasma sheath covering supersonic targets, affecting its stealth performance and monitoring effect of the defense system.
FEKO software is used to establish a simulation model of the supersonic target in the terahertz frequency band, and the RCS characteristics of the target are extracted by establishing single-layer and double-layer plasma sheath models, simulation analysis and meshing.
The RCS characteristics of the plasma sheath coated supersonic target are accurately extracted at different frequencies, improving the target's stealth performance and monitoring accuracy of the defense system.
Smart Images
Figure CN119620030A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of electromagnetic scattering, and in particular to a method for extracting RCS characteristics of a supersonic target covered by a plasma sheath. Background Art
[0002] Radar cross section (RCS) is a physical quantity that describes the ability of a target to reflect electromagnetic waves under the irradiation of a radar beam. It is a quantitative indicator of the target's reflection ability in different directions, usually measured in square meters. The size of the radar cross section depends on factors such as the target's geometry, surface material, and surface treatment technology. A larger radar cross section means that the target is easier to detect in the radar system, and vice versa. In supersonic target technology, radar cross section plays a vital role. As a long-range strike weapon, supersonic targets need to reduce their detectability in radar systems as much as possible when performing missions to improve their survivability and strike effect. Similarly, in the defense system, advanced detection methods need to be used to detect the radar scattering characteristics of supersonic targets of hostile forces as much as possible, identify the status of hostile targets, and conduct precise defense.
[0003] Plasma sheath is a natural phenomenon, and its formation process involves the interaction between ionized gases in the atmosphere and external electromagnetic fields. Under certain conditions, molecules in the atmosphere will lose or gain electrons due to high-energy radiation or electric fields, forming charged plasma. These plasmas will gather around the surface of the target to form a "sheath"-like structure, namely the plasma sheath. Plasma is a charged gas composed of positive and negative charges, and has good electromagnetic properties. They have high electrical conductivity and magnetic permeability, and can absorb, reflect and scatter electromagnetic waves. When electromagnetic waves pass through the plasma sheath, the charged particles of the plasma will interact with the electromagnetic waves, thereby changing the propagation mode of the electromagnetic waves, so that it forms a shielding effect around the target, effectively affecting the electromagnetic properties of the target.
[0004] In the stealth design of supersonic targets, it is an effective means to use plasma sheath to change the electromagnetic characteristics of the target and reduce its radar cross section. By controlling the formation and properties of the plasma sheath, the electromagnetic wave absorption and scattering of the supersonic target can be achieved, making it more difficult to detect in the radar system. This technology can not only improve the stealth performance of supersonic targets, but also enhance their survivability and combat effectiveness, providing strong support for military operations. Therefore, in modern technology, plasma sheath has become an important stealth technology means, which has received widespread attention and application. In the defense system, during the monitoring of the supersonic targets of hostile forces, the atmosphere will be ionized and plasma will be generated due to the process of its hypersonic targets re-entering the atmosphere after leaving the atmosphere. When a large amount of plasma is coated on the surface of the target, a plasma sheath will be formed. This plasma sheath will weaken the radar scattering characteristics of the target and have a certain impact on its monitoring and defense process.
[0005] Terahertz waves refer to electromagnetic waves with a frequency between infrared light and microwaves and a wavelength between 0.1 mm and 1 mm. They are located in a special position in the electromagnetic spectrum and have a relatively long wavelength, which gives them a series of unique characteristics and application potential. Terahertz waves also have important application potential in the field of supersonic target technology. Since terahertz waves can penetrate obstacles such as water vapor, gas and particles in the atmosphere and have high resolution, they have unique advantages in target identification and positioning. Terahertz wave technology can be used for supersonic target identification and tracking, helping the system to accurately lock on to the target and perform strike missions. In terms of supersonic target identification, terahertz waves can penetrate the target surface, obtain information on the internal structure and composition of the target, and identify the type, material and structural characteristics of the target. This helps the system to accurately identify the target, avoid misjudgment of friendly targets or irrelevant targets, and improve the accuracy and effectiveness of supersonic target strikes. In terms of target tracking, terahertz wave technology can achieve real-time tracking and positioning of the target by detecting signals reflected from the target surface. Therefore, the application of terahertz wave technology in the field of supersonic targets will provide the system with more comprehensive and accurate target information, improve combat capability and strike effect, and help enhance the dominant position of supersonic targets on the battlefield. Summary of the invention
[0006] In view of the above problems, the present invention carries out research on the RCS characteristics extraction method of plasma sheath coated supersonic target in the terahertz frequency band based on FEKO, aiming to propose an accurate and efficient RCS extraction method for plasma sheath supersonic target using the terahertz band.
[0007] In order to achieve the purpose of the above invention, the present invention adopts the following technical solutions:
[0008] A method for extracting RCS characteristics of a supersonic target covered by a plasma sheath comprises the following steps:
[0009] Step 1, establishing a simulation model of a supersonic target;
[0010] Step 2, analyzing and testing the RCS characteristics of the supersonic target model;
[0011] Step 3, establishing a single-layer plasma sheath model for the supersonic target model, and analyzing and testing its RCS characteristics;
[0012] Step 4: Establish a double-layer plasma sheath model for the supersonic target model, and analyze and test its RCS characteristics;
[0013] Step 5: Compare and analyze the RCS characteristics extracted in steps 2, 3, and 4.
[0014] Furthermore, step 1 specifically includes:
[0015] S1.1. Establish the supersonic target model required for the experiment in FEKO software, and export the model as a .stp file after the modeling design is completed;
[0016] S1.2, import the established model into FEKO software, open FEKO software and create a project, read the .stp file in S1.1 into the current project;
[0017] S1.3, setting parameters for the model imported in S1.2, wherein the parameters include frequency, wavelength, solution method, incident wave, and polarization mode;
[0018] S1.4. Mesh the model.
[0019] Furthermore, step 2 specifically includes:
[0020] For the model established in step 1, the RCS characteristics of the model at different frequencies are simulated and solved by using the selected algorithm in the FEKO software. After the solution is completed, the RCS characteristics are viewed in the post-processing module of the FEKO software.
[0021] Furthermore, step 3 specifically includes:
[0022] S3.1, single-layer plasma sheath model modeling, on the supersonic target model established in S1.1, a single-layer plasma sheath model is further established, and the single-layer plasma sheath model is modeled as a layer covering the outside of the supersonic target model;
[0023] S3.2, setting parameters for the established single-layer plasma sheath model, and simulating the plasma sheath formed in reality by setting parameters such as the dielectric constant, loss tangent, and magnetic permeability of the single-layer plasma sheath model;
[0024] S3.3, setting parameters for the model of the single-layer plasma sheath, including the setting of parameters such as frequency, wavelength, solution method, incident wave, and polarization mode;
[0025] S3.4, meshing the single-layer plasma sheath model after setting parameters;
[0026] S3.5. According to the algorithm selected in step 2, the same parameter settings and solution methods are used to simulate and extract the model covered by the single-layer plasma sheath. After the solution is completed, the RCS characteristics are checked in the post-processing module of the FEKO software.
[0027] Furthermore, step 4 specifically includes:
[0028] S4.1. On the basis of the supersonic target model established in S1.1 and the single-layer plasma sheath model established in S3.1, a double-layer plasma sheath model is established. The double-layer plasma sheath model is based on the single-layer plasma sheath model and then coated on the outside of the supersonic target model. A total of two-layer plasma sheath models are established.
[0029] S4.2. On the basis of the established double-layer plasma sheath model, parameters of the established double-layer plasma sheath model are set, and different dielectric constants, loss tangents, and magnetic permeabilities are set for the outer two layers of the plasma sheath model;
[0030] S4.3, setting parameters for the model of the double-layer plasma sheath, setting the parameters required for the simulation calculation, such as frequency, wavelength, solution method, incident wave, and polarization mode, and performing simulation analysis on the RCS characteristics of the model of the double-layer plasma sheath at different frequencies;
[0031] S4.4, meshing the double-layer plasma sheath model with set parameters;
[0032] S4.5. Extract the RCS characteristics of the double-layer plasma sheath model and view it in the post-processing module of FEKO software.
[0033] Furthermore, in step 1, a cone model and a waverider model are modeled.
[0034] Furthermore, the RCS characteristics of supersonic targets are extracted in the terahertz frequency band.
[0035] Furthermore, the RCS characteristics of supersonic targets are extracted at four frequencies: 94 GHz, 220 GHz, 340 GHz and 850 GHz.
[0036] Compared with the prior art, the present invention has the following beneficial effects:
[0037] Compared with traditional methods, terahertz waves have stronger penetration, and can accurately extract the RCS characteristics of supersonic target models and supersonic target models covered with plasma sheaths, and provide more valuable references. This is convenient for providing more favorable conditions for supersonic targets covered with plasma sheaths, and further optimizing the design of supersonic targets to improve the stealth effect of targets. At the same time, for defense systems, it can monitor the status of hostile forces more accurately and defend against enemy targets in a timely and accurate manner. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Figure 1 It is a flow chart of the overall steps of the present invention;
[0039] Figure 2 Figures 2 are diagrams of two supersonic target models in a specific embodiment of the present invention, wherein (a) is a cone model and (b) is a waverider model;
[0040] Figure 3 The figures are single-layer and double-layer plasma sheath model diagrams of two supersonic target models in a specific embodiment of the present invention, wherein (a) is a conical single-layer plasma sheath model, (b) is a conical double-layer plasma sheath model, (c) is a waverider single-layer plasma sheath model, and (d) is a waverider double-layer plasma sheath model. DETAILED DESCRIPTION
[0041] In order to make the objectives, technical solutions and advantages of the present application clearer, the specific implementation methods of the present invention will be described in more detail below with reference to the accompanying drawings and embodiments.
[0042] In recent years, many electromagnetic simulation software for RCS characteristics research have emerged, providing a powerful platform for the extraction of RCS characteristics. FEKO has become one of the important research tools for RCS characteristics simulation and extraction because it can accurately simulate the electromagnetic characteristics of the target structure and extract the RCS characteristics of the target.
[0043] A specific embodiment of the present invention provides a method for extracting the RCS characteristics of a plasma sheath covering a supersonic target in the terahertz band based on FEKO. The method includes establishing two common different types of models and extracting their RCS characteristics in the terahertz band respectively; at the same time, a single-layer and double-layer plasma sheath model is further established for the established model. The four established models are as follows: Figure 3 As shown, the RCS characteristics are then extracted at four different frequencies: 94 GHz, 220 GHz, 340 GHz, and 850 GHz. The following is a detailed implementation method. Figure 1 As shown:
[0044] S1. Establish a simulation model of supersonic targets
[0045] According to the demand analysis, a simulation model of the RCS characteristics of the plasma sheath covering the target is established, and two types of models, the common cone model and the waverider model, are modeled in the present invention. The model is as follows: Figure 2 As shown, they are respectively used for subsequent experimental tests of the present invention.
[0046] This step includes 4 sub-steps:
[0047] S1.1. Establish the supersonic target model required for the experiment
[0048] Due to the particularity of the object under study, it is difficult to obtain the detailed shape and design data parameters of its model. The experimental model of the present invention adopts a model similar to the actual supersonic target, and the supersonic target model required for this experiment is modeled under FEKO software or other similar simulation software. In order to facilitate the subsequent further simulation experiment design, the present invention exports the model after the modeling design is completed as a .stp file. In the present invention, two types of supersonic target models, a cone model and a waverider model, are established as needed. The model is as follows Figure 2 shown.
[0049] S1.2. Import the established model into FEKO software
[0050] Open FEKO software and create a project, read the .stp model file created in S1.1 into the current project.
[0051] S1.3. Set parameters for the imported model
[0052] In order to facilitate the subsequent experimental analysis, the model imported in S1.2 needs to set its parameters, including frequency, wavelength, solution method, incident wave, polarization mode, etc. For the setting of its frequency parameters, in this example, the RCS characteristics of the model are extracted and analyzed at four frequencies: 94 GHz, 220 GHz, 340 GHz, and 850 GHz.
[0053] S1.4. Grid Division
[0054] After setting the basic model parameters in S1.3, in order to accurately calculate and extract the results, the model needs to be meshed so that the FEKO software can solve it later. Meshing plays a key role in the subsequent solution. The quality of meshing closely affects the accuracy of the subsequent simulation results. Poor meshing quality will affect the accuracy of the subsequent simulation results. Too dense meshing will require a lot of computer memory for calculation during the solution process, which requires high computer performance and is very time-consuming.
[0055] S2. Analyze and test the RCS characteristics of the target model
[0056] For the two models established in S1, the RCS characteristics of different models at four frequencies of 94GHz, 220GHz, 340GHz, and 850GHz are extracted in FEKO. The RCS characteristics of various aspects that need to be tested are extracted as needed for subsequent comparative analysis.
[0057] After setting the parameters and meshing the imported model in FEKO software, the RCS characteristics of the model are simulated and extracted using the selected algorithm. After the solution is completed, the RCS characteristics can be viewed in the post-processing module of FEKO.
[0058] S3. Establish a single-layer plasma sheath model for the target model and analyze and test its RCS characteristics
[0059] Based on the two supersonic target models established in S1, a plasma sheath model with a single layer of plasma is established. Figure 3 (a) and Figure 3 After the model is established, the RCS characteristics of the single-layer plasma sheath model at different frequencies of 94 GHz, 220 GHz, 340 GHz, and 850 GHz are extracted in FEKO.
[0060] Specifically, this step includes 5 sub-steps:
[0061] S3.1. Modeling of single-layer plasma sheath
[0062] Based on the basic model established in S1.1, it is necessary to further establish a single-layer plasma sheath model. The single-layer plasma sheath model is a layer covering the outside of the basic model. In this example, two single-layer plasma sheath models of cone model and waverider model are established. The models are as follows: Figure 3 (a) and Figure 3 (c) as shown.
[0063] S3.2. Setting the parameters of the single-layer plasma sheath
[0064] On the basis of the established single-layer plasma sheath model, in order to reflect the properties of its plasma sheath, it is necessary to set the parameters of the established single-layer plasma sheath model. By setting the dielectric constant, loss tangent, magnetic permeability and other parameters of its outer plasma sheath model, the plasma sheath formed in reality can be simulated.
[0065] S3.3. Parameter setting for the model of the single-layer plasma sheath
[0066] The parameters required for the simulation calculation of the established single-layer plasma sheath model are set, mainly including the setting of its frequency, wavelength, solution method, incident wave, polarization mode and other parameters. In this example, the RCS characteristics of the model covered with a single-layer plasma sheath are simulated and analyzed at four frequencies: 94 GHz, 220 GHz, 340 GHz and 850 GHz.
[0067] S3.4. Meshing of single-layer plasma sheath model
[0068] For the single-layer plasma sheath model with set parameters, the present invention also needs to perform grid division on it like the basic model, and the requirements for its division are the same as those for the basic model, and both need to balance the requirements of performance and simulation speed.
[0069] S3.5. Extraction of RCS characteristics of single-layer plasma sheath model
[0070] According to the simulation algorithm set in S2, the same parameter setting and solution method are used to simulate and extract the model of the single-layer plasma sheath. After the solution is completed, its RCS characteristics are checked in the post-processing module of FEKO.
[0071] S4. Establish a double-layer plasma sheath model for the supersonic target model and analyze and test its RCS characteristics
[0072] Based on the target model established in S1 and the single-layer plasma sheath model established in S3, a double-layer plasma sheath model is established according to the requirements. Figure 3(b) and Figure 3 (d) The RCS characteristics at four frequencies of 94 GHz, 220 GHz, 340 GHz, and 850 GHz are extracted in FEKO.
[0073] Specifically, this step includes 5 sub-steps:
[0074] S4.1. Modeling of double-layer plasma sheath
[0075] Based on the basic warhead model established in S1 and the single-layer plasma sheath model established in S3.1, a double-layer plasma sheath model is established in the same way. The double-layer plasma sheath model is built on the basis of the single-layer model and then covered on the outside of the basic model. A total of two plasma sheath models are established. In this example, two double-layer plasma sheath models of cone model and waverider model are established. The models are as follows: Figure 3 (b) and Figure 3 (d) as shown.
[0076] S4.2. Setting the parameters of the double-layer plasma sheath
[0077] On the basis of the established double-layer plasma sheath model, in order to reflect the properties of its plasma sheath, it is necessary to set the parameters of the established double-layer plasma sheath model. As with the single layer, the dielectric constant, loss tangent, magnetic permeability and other parameters of the outer plasma sheath model are set to simulate the plasma sheath formed in reality. In the double-layer plasma sheath model, different dielectric constants, loss tangents, magnetic permeabilities and other parameters need to be set for the two outer layers respectively, so as to reflect the two different plasma sheaths wrapped outside the basic model.
[0078] S4.3. Parameter setting for the model of the double-layer plasma sheath
[0079] The established double-layer plasma sheath model is set with the same parameters as the single-layer model, such as frequency, wavelength, solution method, incident wave, polarization mode, etc. In this example, the RCS characteristics of the model covered with a double-layer plasma sheath are simulated and analyzed at four frequencies: 94 GHz, 220 GHz, 340 GHz, and 850 GHz.
[0080] S4.4. Meshing of double-layer plasma sheath model
[0081] For the double-layer plasma sheath model with set parameters, mesh it according to the single-layer model meshing method to balance the performance and simulation speed.
[0082] S4.5. RCS characteristics extraction of double-layer plasma sheath model
[0083] The RCS characteristics are extracted according to the extraction method of the single-layer model and viewed in the post-processing module of FEKO.
[0084] S5. Comparative analysis of the RCS characteristics extracted in three cases
[0085] A comparative analysis is performed on the RCS characteristics extracted in the three cases of S2, S3, and S4, that is, the RCS characteristics of the basic model, single-layer model, and double-layer model extracted in the previous steps are compared and analyzed, and their RCS characteristics are summarized.
[0086] The present invention provides a method for extracting the RCS characteristics of a plasma-coated supersonic target in the terahertz frequency band based on FEKO, which can accurately extract the RCS characteristics of the target coated by the plasma sheath. In a specific embodiment of the present invention, a supersonic target model is analyzed and tested in detail at four frequencies of 94 GHz, 220 GHz, 340 GHz, and 850 GHz to extract the RCS characteristics of the target at different frequencies.
[0087] Based on the method of the present invention, the target's stealth capability and the ability to monitor and strike hostile targets can be further improved by analyzing the extracted RCS characteristics.
[0088] The present invention uses FEKO software to model the structure of the supersonic target and the plasma sheath model, and combines the optimization algorithm and the numerical analysis method to simulate and analyze it, which can comprehensively and accurately detect and analyze the RCS characteristics of the target covered by the plasma sheath. Through the method of the present invention, the stealth performance of the supersonic target and the monitoring and striking capability of the defense system can be accurately evaluated, providing strong support for the design and improvement of the stealth target and the monitoring of the defense system, and promoting the progress and development of supersonic target research and its defense technology.
[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, several modifications and improvements may be made without departing from the principle of the present invention, and these should also be regarded as falling within the scope of protection of the present invention.
Claims
1. A method for extracting RCS characteristics of a supersonic target covered by a plasma sheath, characterized in that: The following steps are involved: Step 1, establishing a simulation model of a supersonic target; Step 2, analyzing and testing the RCS characteristics of the supersonic target model; Step 3, establishing a single-layer plasma sheath model for the supersonic target model, and analyzing and testing its RCS characteristics; Step 4: Establish a double-layer plasma sheath model for the supersonic target model, and analyze and test its RCS characteristics; Step 5: Compare and analyze the RCS characteristics extracted in steps 2, 3, and 4.
2. A method for extracting RCS characteristics of a supersonic target covered by a plasma sheath according to claim 1, characterized in that: Step 1 specifically includes: S1.
1. Establish the supersonic target model required for the experiment in FEKO software, and export the model after modeling and design as a .stp file; S1.2, import the established model into FEKO software, open FEKO software and create a project, read the .stp file in S1.1 into the current project; S1.3, setting parameters for the model imported in S1.2, wherein the parameters include frequency, wavelength, solution method, incident wave, and polarization mode; S1.
4. Mesh the model.
3. A method for extracting RCS characteristics of a supersonic target covered by a plasma sheath according to claim 2, characterized in that: Step 2 specifically includes: For the model established in step 1, the RCS characteristics of the model at different frequencies are simulated and solved by using the selected algorithm in the FEKO software. After the solution is completed, the RCS characteristics are viewed in the post-processing module of the FEKO software.
4. A method for extracting RCS characteristics of a supersonic target covered by a plasma sheath according to claim 3, characterized in that: Step 3 specifically includes: S3.1, single-layer plasma sheath model modeling, on the supersonic target model established in S1.1, a single-layer plasma sheath model is further established, and the single-layer plasma sheath model is modeled as a layer covering the outside of the supersonic target model; S3.2, setting parameters for the established single-layer plasma sheath model, and simulating the plasma sheath formed in reality by setting parameters such as the dielectric constant, loss tangent, and magnetic permeability of the single-layer plasma sheath model; S3.3, setting parameters for the model of the single-layer plasma sheath, including the setting of parameters such as frequency, wavelength, solution method, incident wave, and polarization mode; S3.4, meshing the single-layer plasma sheath model after setting parameters; S3.
5. According to the algorithm selected in step 2, the same parameter settings and solution methods are used to simulate and extract the model covered by the single-layer plasma sheath. After the solution is completed, the RCS characteristics are checked in the post-processing module of the FEKO software.
5. A method for extracting RCS characteristics of a supersonic target covered by a plasma sheath according to claim 4, characterized in that: Step 4 specifically includes: S4.
1. On the basis of the supersonic target model established in S1.1 and the single-layer plasma sheath model established in S3.1, a double-layer plasma sheath model is established. The double-layer plasma sheath model is based on the single-layer plasma sheath model and then coated on the outside of the supersonic target model. A total of two-layer plasma sheath models are established. S4.
2. On the basis of the established double-layer plasma sheath model, parameters of the established double-layer plasma sheath model are set, and different dielectric constants, loss tangents, and magnetic permeabilities are set for the outer two layers of the plasma sheath model; S4.3, setting parameters for the model of the double-layer plasma sheath, setting the parameters required for the simulation calculation, such as frequency, wavelength, solution method, incident wave, and polarization mode, and performing simulation analysis on the RCS characteristics of the model of the double-layer plasma sheath at different frequencies; S4.4, meshing the double-layer plasma sheath model with set parameters; S4.
5. Extract the RCS characteristics of the double-layer plasma sheath model and view it in the post-processing module of FEKO software.
6. The method for extracting RCS characteristics of a supersonic target covered by a plasma sheath according to claim 1, characterized in that: In step 1, the cone model and the waverider model are modeled.
7. The method for extracting RCS characteristics of a supersonic target covered by a plasma sheath according to claim 1, characterized in that: The RCS characteristics of supersonic targets are extracted in the terahertz frequency band.
8. The method for extracting RCS characteristics of a supersonic target covered by a plasma sheath according to claim 7, characterized in that: The RCS characteristics of supersonic targets are extracted at four frequencies: 94 GHz, 220 GHz, 340 GHz and 850 GHz.