A sea clutter simulation method, device and medium

Abstract

The present application discloses a method, device and medium for simulating sea clutter, the method comprising: obtaining the illumination azimuth and elevation angle of the beam through a radar, calculating according to the illumination azimuth and elevation angle to obtain a clutter area; dividing according to the clutter area to determine a plurality of triangular face elements; determining a plurality of relative positional relationships between the radar and the plurality of triangular face elements to determine a plurality of incident angles corresponding to the plurality of triangular face elements according to the plurality of positional relationships; determining a plurality of backscatter coefficients corresponding to the plurality of triangular face elements according to the plurality of incident angles, and determining an echo amplitude corresponding to the plurality of triangular face elements according to the backscatter coefficients; determining a transfer function according to the echo amplitude, and convolving the transfer function to obtain a clutter signal. The present application determines the clutter area by accurately calculating the illumination azimuth and elevation angle of the radar beam, and refines the clutter characteristics according to terrain information, thereby improving the accuracy and authenticity of the simulation.

Description

Technical Field

[0001] The present application relates to the field of radar communication technology, and in particular to a sea clutter simulation method, device and medium. Background Art

[0002] Sea clutter simulation methods are mainly divided into statistical distribution models and backscatter coefficient models. The statistical model assumes that the echo amplitude obeys a certain probability distribution, such as log-normal distribution, Weibull distribution and K distribution. By setting the shape and scale parameters of the probability distribution, the corresponding random data is generated as the simulated data after sea clutter detection. In addition to the amplitude satisfying a certain distribution, there is generally a certain correlation between the data, which is a correlated random process. The method of modeling sea clutter as a random process is usually the spherically invariant random process method (SIRP) and the zero memory nonlinear transformation method (ZMNL). The key to SIRP is to find the complex nonlinear correspondence between the correlation functions of the input and output sequences, while ZMNL is limited by the autocorrelation function and order of the required sequence. At the same time, this method is not easy to form a fast algorithm and the amount of calculation is very large.

[0003] When airborne radar detects targets at sea, it often faces a strong sea clutter environment. Sea clutter will generate a large number of false alarms after radar signal processing, which will seriously affect the detection and tracking performance of the radar. Since the characteristics of sea clutter are affected by many factors such as sea conditions, beam incidence angle, and radar polarization mode, the modeling of sea clutter becomes extremely complex. Summary of the invention

[0004] In order to solve the above problems, the present application proposes a sea clutter simulation method, comprising: obtaining an illumination azimuth and an elevation angle of a beam through a radar, and performing calculations according to the illumination azimuth and the elevation angle to obtain a clutter region; performing segmentation according to the clutter region to determine a plurality of triangular surface elements; determining a plurality of relative positional relationships between the radar and the plurality of triangular surface elements to determine a plurality of incident angles corresponding to the plurality of triangular surface elements according to the plurality of positional relationships; determining backscatter coefficients corresponding to the plurality of triangular surface elements according to the plurality of incident angles, and determining echo amplitudes corresponding to the plurality of triangular surface elements according to the backscatter coefficients; determining a transfer function according to the echo amplitude, and performing convolution on the transfer function to obtain a clutter signal.

[0005] In one example, a calculation is performed based on the illumination azimuth and the pitch angle to obtain a clutter area, specifically including: determining an elliptical area illuminated by an antenna, and determining terrain information corresponding to the elliptical area, and determining area attributes of the elliptical area based on the terrain information; determining a circumscribed rectangle corresponding to the elliptical area based on the area attributes, and determining the clutter area based on the circumscribed rectangle.

[0006] In one example, determining the echo amplitudes corresponding to the multiple triangular surface elements according to the backscatter coefficient specifically includes: triangulating the clutter area to divide the planar object of the clutter area into multiple triangular surface elements; determining parameters corresponding to the multiple triangular surface elements, and performing calculations based on the parameters to obtain areas corresponding to the multiple triangular surface elements; performing RCS calculations based on the areas corresponding to the multiple triangular surface elements and the backscatter coefficient to determine the echo amplitude.

[0007] In one example, the backscattering coefficients corresponding to the multiple triangular face elements are determined according to the multiple incident angles, specifically including: determining model parameters, the model parameters including but not limited to frequency, incident angle, and sea conditions; normalizing the model parameters, and determining a backscattering coefficient model according to the processed model parameters, so as to determine the backscattering coefficient according to the backscattering coefficient model.

[0008] In one example, the method further includes: determining a plurality of centroids corresponding to the plurality of triangular facets, and determining the echo amplitudes of the plurality of centroids, wherein the calculation formula for the echo amplitude is:

[0009]

[0010] in, is the radar transmitting power, and are the transmitting antenna gains and the receiving antenna gains, is the radar operating wavelength, is the normalized scattering coefficient of the ith triangle surface element, is the area of ​​the ith triangle face, is the distance from the radar to the centroid of the triangle surface element, , , , is the coordinate of the centroid of the nth triangle element in the antenna coordinate system, Radar system loss.

[0011] In one example, determining the transfer function according to the echo amplitude specifically includes: calculating multiple distance unit indexes of the multiple centroids, and the calculation formula is:

[0012]

[0013] in, is the speed of light, is the sampling rate, represents a floor function; determining identical items among the plurality of distance unit indices, and accumulating and summing the centroids corresponding to the identical items to obtain the transfer function.

[0014] In one example, the method further includes: determining a transmission signal of the radar, which is expressed as:

[0015]

[0016] in, For time, is the carrier frequency, is the linear frequency modulation rate of change; B is the signal bandwidth; T is the pulse width; is a rectangular signal, , is the complex envelope of the signal, is the initial phase.

[0017] In one example, the method further includes: convolving the transmit signal and the transfer function to obtain the clutter signal.

[0018] On the other hand, the present application also proposes a sea clutter simulation device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the sea clutter simulation device can execute: acquiring the illumination azimuth and elevation angle of the beam through a radar, and calculating according to the illumination azimuth and the elevation angle to obtain a clutter area; dividing according to the clutter area to determine a plurality of triangular face elements; determining a plurality of relative positional relationships between the radar and the plurality of triangular face elements, and determining a plurality of incident angles corresponding to the plurality of triangular face elements according to the plurality of positional relationships; determining backscatter coefficients corresponding to the plurality of triangular face elements according to the plurality of incident angles, and determining echo amplitudes corresponding to the plurality of triangular face elements according to the backscatter coefficients; determining a transfer function according to the echo amplitude, and convolving the transfer function to obtain a clutter signal.

[0019] On the other hand, the present application also proposes a non-volatile computer storage medium storing computer executable instructions, wherein the computer executable instructions are configured to: obtain the illumination azimuth and elevation angle of the beam through a radar, and perform calculations based on the illumination azimuth and the elevation angle to obtain a clutter area; perform segmentation based on the clutter area to determine a plurality of triangular surface elements; determine a plurality of relative positional relationships between the radar and the plurality of triangular surface elements to determine a plurality of incident angles corresponding to the plurality of triangular surface elements based on the plurality of positional relationships; determine backscatter coefficients corresponding to the plurality of triangular surface elements based on the plurality of incident angles, and determine echo amplitudes corresponding to the plurality of triangular surface elements based on the backscatter coefficients; determine a transfer function based on the echo amplitude, and perform convolution on the transfer function to obtain a clutter signal.

[0020] The present application determines the clutter area by accurately calculating the irradiation azimuth and pitch angle of the radar beam, and refines the clutter characteristics according to the terrain information, thereby improving the accuracy and authenticity of the simulation. The present application adopts triangular facet subdivision technology, which can carefully depict the geometric characteristics of the clutter area, making the calculation of the backscattering coefficient more accurate, thereby improving the prediction accuracy of the echo amplitude. In addition, by normalizing the model parameters and applying the backscattering coefficient model, the influence of environmental parameter changes on the simulation results is effectively reduced, and the adaptability and stability of the method are enhanced. At the same time, the present application also provides a detailed echo amplitude calculation formula and transfer function determination steps, which are easy to implement and verify, and ensure the repeatability and reliability of the simulation results. Finally, combined with the introduction of linear frequency modulation signals, the simulated clutter signal is closer to the complex environment in actual radar detection, providing strong support for radar system performance evaluation and target detection algorithm verification. In summary, the present application performs well in improving the accuracy of sea clutter simulation, enhancing adaptability and stability, and has important application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0022] Figure 1 A schematic diagram of a flow chart of a sea clutter simulation method in an embodiment of the present application;

[0023] Figure 2 A schematic diagram of beam irradiation in an embodiment of the present application;

[0024] Figure 3 This is an approximate schematic diagram of the regional rectangle in the embodiment of the present application;

[0025] Figure 4 Schematic diagram of a sea clutter simulation device in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0027] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0028] like Figure 1 As shown, in order to solve the above problems, an embodiment of the present application provides a sea clutter simulation method, the method comprising:

[0029] S101. Acquire an illumination azimuth and an elevation angle of a beam through a radar, and perform calculation according to the illumination azimuth and the elevation angle to obtain a clutter area.

[0030] The radar acquires the beam, and calculates the rectangular area corresponding to the clutter according to the azimuth and elevation angle of the radar beam. The digital sea surface in the clutter area is constructed using the three-dimensional form of the JONSWAP spectrum.

[0031] In one embodiment, Figure 2 As shown in the figure, before calculating clutter, it is necessary to determine the clutter area and the area illuminated by the beam. The clutter area calculation is to determine the elliptical area illuminated by the beam antenna and extract the terrain or sea condition data corresponding to this area from the simulation resource library for clutter calculation. Assuming that the illuminated area is a plane, the slope range expression of the ellipse is:

[0032]

[0033] The beam center coordinates are , is the elevation angle, R is the slant distance from the radar to the beam center, is the length of the longitudinal semi-axis, is the transverse semi-axis length, is the rotation angle. The length of the longitudinal semi-axis is , is the antenna azimuth half-power beamwidth, and the length of the horizontal semi-axis is calculated as follows:

[0034]

[0035] is the antenna elevation half-power beamwidth, is the ground grazing angle corresponding to the beam center, is the length from the beam center to the lower half beam point, It is the length from the beam center to the upper half beam point.

[0036] The formula for calculating the area of ​​an ellipse is:

[0037]

[0038] when Very small, satisfying When , the above formula can be approximated as:

[0039]

[0040] The area of ​​the ellipse is used to evaluate how well the enclosing rectangle approximates the ellipse.

[0041] In one embodiment, Figure 3 As shown, the circumscribed rectangle approximation is adopted, as shown by the solid rectangular line in the figure, which can quickly determine the area of ​​the clutter region. The antenna irradiates different azimuth angles to obtain different elliptical shapes as shown in the figure.

[0042] The circumscribed rectangle is represented by its four vertices, and the intersection expression of its slope-distance curve is:

[0043]

[0044] in, , is the slope of the straight line, , , , They are points on the straight line, corresponding to the vertices of the major and minor axes of the ellipse.

[0045] Will be like Figure 3 Substituting the midpoints A, B, C, and D into the above formula, we can obtain the horizontal and vertical coordinates of the intersection points E, F, G, and H respectively:

[0046]

[0047]

[0048]

[0049]

[0050] Then order:

[0051]

[0052] in, , The horizontal and vertical coordinates of the lower left and upper right points of the circumscribed rectangle of the corresponding rectangle. The area of ​​the shape enclosed by the corresponding four straight lines is the area of ​​the circumscribed rectangle. The calculation of clutter echoes in the determined area can greatly reduce the amount of real-time calculation operations.

[0053] In one embodiment, the digital sea surface in the clutter region is constructed using the three-dimensional form of the JONSWAP spectrum. The precise expression of the JONSWAP spectrum is:

[0054]

[0055] in, is a dimensionless constant, and its expression is:

[0056]

[0057] is the wind area (fetch), It represents the average wind speed at 10m above sea level. is the acceleration due to gravity, is the spectrum peak frequency, and its expression is:

[0058]

[0059] is the peak lifting factor, and the average value is 3.3. is the shape parameter, and its calculation formula is:

[0060]

[0061] Since the sea surface is three-dimensional, two-dimensional waves need to be converted into three-dimensional sea surface. When the wind direction is constant, the sea surface satisfies a certain wave spectrum in the direction of the wind. The JONSWAP directional spectrum can be expressed as:

[0062]

[0063] in,

[0064]

[0065] The parameters are represented as:

[0066]

[0067] S102: performing segmentation according to the clutter region to determine a plurality of triangular facets.

[0068] Triangulation is the subdivision of planar objects into triangles, and by extension, of higher-dimensional geometric objects into simplexes. Using the triangulated facet method, a digital triangulated sea surface is constructed in the cluttered area.

[0069] S103. Determine a plurality of relative positional relationships between the radar and the plurality of triangular surface elements, and determine a plurality of incident angles corresponding to the plurality of triangular surface elements according to the plurality of relative positional relationships.

[0070] According to the relative position relationship between the radar and the target, the incident angle of the radar relative to each face element is calculated.

[0071] In one embodiment, the triangular facet parameters are mainly used for RCS calculation. RCS is the product of the backscatter coefficient and the facet area. Therefore, it is necessary to calculate the facet parameters, including the area and the grazing angle, that is, the incident angle. The grazing angle can be solved based on the radar line of sight and the facet normal vector.

[0072] From the coordinates of the triangle vertices , calculate the unit normal of the triangle ,area and centroid They are:

[0073]

[0074] Assume the radar position coordinates are , then the line connecting the radar and the incenter of the triangle The calculation formula is:

[0075]

[0076] According to the line connecting the radar and the inner center of the triangle With triangle unit normal , the grazing angle of the beam relative to the triangle plane can be calculated , the calculation formula is:

[0077]

[0078] S104. Determine backscatter coefficients corresponding to the plurality of triangular surface elements according to the plurality of incident angles, and determine echo amplitudes corresponding to the plurality of triangular surface elements according to the backscatter coefficients.

[0079] The NRL model is used to calculate the RCS corresponding to each facet. The radar equation is used to calculate the amplitude of the echo, and the distance between the radar and the target is used to calculate the phase of the echo.

[0080] In one embodiment, in order to consider the effects of polarization, frequency, incident angle, and sea conditions, the Naval Research Laboratory (NRL) provides an empirical model to minimize the mean absolute error. The normalized scattering coefficient calculation formula is:

[0081]

[0082] in, is the grazing angle in degrees, For sea conditions, is the radar frequency in GHz. The value of is calculated through empirical formula, as shown in the following table:

[0083]

[0084] Then, the RCS corresponding to each facet is obtained according to the calculated scattering coefficient and the area of ​​the triangular facet. The calculation formula is:

[0085]

[0086] in, is the RCS of the triangle surface element, is the area of ​​the triangular surface.

[0087] S105 . Determine a transfer function according to the echo amplitude, and perform convolution on the transfer function to obtain a clutter signal.

[0088] According to the radar range resolution, the system transfer function of the digital sea surface is calculated. The transmitted signal is convolved with the system transfer function to generate a clutter echo signal.

[0089] In one embodiment, a radar equation is predetermined, and its expression is:

[0090]

[0091] in, is the radar receiving power, is the radar transmitting power, is the transmit antenna gain, is the gain of the receiving antenna, is the radar operating wavelength, is the radar system loss, For RCS.

[0092] Calculate the echo amplitude of the centroid of each triangular surface element, and the calculation formula is:

[0093]

[0094] in, is the normalized scattering coefficient of the ith surface element, is the area of ​​the ith surface element, is the distance from the radar to the centroid of the surface element, . is the coordinate of the centroid of the nth element in the antenna coordinate system.

[0095] Second, the range cell index of the radar line of sight projection for each centroid is calculated as:

[0096]

[0097] in, is the speed of light, is the sampling rate, Represents the floor function.

[0098] Finally, the centroids within the same distance index are accumulated and summed to obtain the transfer function, and the summation formula is:

[0099]

[0100] in, is the system transfer function, which is a one-dimensional array.

[0101] In one embodiment, the transmission signal is convolved with the system transfer function to obtain a clutter signal, which is calculated as follows:

[0102]

[0103] in, is the radar transmission signal, which is generally phase-coded, linear frequency modulation signal, etc. In order to maintain generality, it is assumed that the transmission signal is a linear frequency modulation signal, and its expression is:

[0104]

[0105] in, For time, is the carrier frequency, is the linear frequency modulation rate, B is the signal bandwidth, T is the pulse width, is a rectangular signal, , is the complex envelope of the signal, is the initial phase.

[0106] The present application significantly improves the accuracy and authenticity of the simulation by accurately calculating the irradiation azimuth and elevation angle of the radar beam and refining the clutter characteristics in combination with terrain information. This feature makes the simulation results closer to the actual sea clutter environment, providing a reliable basis for radar system performance evaluation and target detection algorithm verification. The triangular facet subdivision technology can be used to carefully depict the geometric characteristics of the clutter area, making the calculation of the backscatter coefficient more accurate. Not only does it improve the prediction accuracy of the echo amplitude, but it also enhances the meticulousness of the simulation results. By normalizing the model parameters and applying the backscatter coefficient model, the impact of changes in environmental parameters on the simulation results is effectively reduced. The method of the present application can maintain good stability and adaptability under different sea conditions and radar parameters. The present application provides a detailed echo amplitude calculation formula and transfer function determination steps for easy implementation and verification. This not only simplifies the complexity of the simulation process, but also ensures the repeatability and reliability of the simulation results. The present application also combines the introduction of linear frequency modulation signals to make the simulated clutter signals closer to the complex environment in actual radar detection. This feature helps to more accurately evaluate the performance of radar systems in complex environments. This application has excellent performance in improving sea clutter simulation accuracy, enhancing adaptability and stability, and has important application value. It can be widely used in radar system design, performance evaluation, and target detection algorithm verification, providing strong support for related research and applications.

[0107] like Figure 4 As shown, the embodiment of the present application also provides a sea clutter simulation device, including:

[0108] at least one processor; and,

[0109] a memory communicatively connected to at least one processor; wherein,

[0110] The memory stores instructions executable by at least one processor, the instructions being executed by at least one processor to enable a sea clutter simulation device to perform:

[0111] Acquire the illumination azimuth and elevation angle of the beam through the radar, and perform calculation according to the illumination azimuth and the elevation angle to obtain the clutter area;

[0112] Performing segmentation according to the clutter region to determine a plurality of triangular face elements;

[0113] Determining a plurality of relative positional relationships between the radar and the plurality of triangular surface elements, so as to determine a plurality of incident angles corresponding to the plurality of triangular surface elements according to the plurality of relative positional relationships;

[0114] Determine backscatter coefficients corresponding to the plurality of triangular facets according to the plurality of incident angles, and determine echo amplitudes corresponding to the plurality of triangular facets according to the backscatter coefficients;

[0115] A transfer function is determined according to the echo amplitude, and convolution is performed on the transfer function to obtain a clutter signal.

[0116] The embodiment of the present application further provides a non-volatile computer storage medium storing computer executable instructions, wherein the computer executable instructions are configured as follows:

[0117] Acquire the illumination azimuth and elevation angle of the beam through the radar, and perform calculation according to the illumination azimuth and the elevation angle to obtain the clutter area;

[0118] Performing segmentation according to the clutter region to determine a plurality of triangular face elements;

[0119] Determining a plurality of relative positional relationships between the radar and the plurality of triangular surface elements, so as to determine a plurality of incident angles corresponding to the plurality of triangular surface elements according to the plurality of relative positional relationships;

[0120] Determine backscatter coefficients corresponding to the plurality of triangular facets according to the plurality of incident angles, and determine echo amplitudes corresponding to the plurality of triangular facets according to the backscatter coefficients;

[0121] A transfer function is determined according to the echo amplitude, and convolution is performed on the transfer function to obtain a clutter signal.

[0122] In the 1990s, it was very clear whether the improvement of a technology was hardware improvement (for example, improvement of the circuit structure of diodes, transistors, switches, etc.) or software improvement (improvement of the method flow). However, with the development of technology, many improvements of the method flow today can be regarded as direct improvements of the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be implemented with hardware entity modules. For example, a programmable logic device (PLD) (such as a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user's programming of the device. Designers can "integrate" a digital system on a PLD by programming it themselves, without having to ask chip manufacturers to design and make dedicated integrated circuit chips. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly implemented by "logic compiler" software, which is similar to the software compiler used when developing and writing programs, and the original code before compilation must also be written in a specific programming language, which is called hardware description language (HDL). There is not only one kind of HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also know that it is only necessary to program the method flow slightly in the above-mentioned hardware description languages ​​and program it into the integrated circuit, and then it is easy to obtain the hardware circuit that implements the logic method flow.

[0123] The controller may be implemented in any suitable manner, for example, the controller may take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (e.g., software or firmware) executable by the (micro)processor, a logic gate, a switch, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller, examples of which include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320, and the memory controller may also be implemented as part of the control logic of the memory. It is also known to those skilled in the art that, in addition to implementing the controller in a purely computer-readable program code manner, the controller may be implemented in the form of a logic gate, a switch, an application-specific integrated circuit, a programmable logic controller, and an embedded microcontroller by logically programming the method steps. Therefore, such a controller may be considered as a hardware component, and the devices for implementing various functions included therein may also be considered as structures within the hardware component. Or even, the devices for implementing various functions may be considered as both software modules for implementing the method and structures within the hardware component.

[0124] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0125] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0126] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0127] The devices and media provided in the embodiments of the present application correspond one-to-one to the methods. Therefore, the devices and media also have similar beneficial technical effects as the corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0128] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0129] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0130] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0132] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0133] Memory may include non-permanent storage in a computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0134] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0135] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0136] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A sea clutter simulation method, characterized in that: include: Acquire the illumination azimuth and elevation angle of the beam through the radar, and perform calculation according to the illumination azimuth and the elevation angle to obtain the clutter area; Performing segmentation according to the clutter region to determine a plurality of triangular face elements; Determining a plurality of relative positional relationships between the radar and the plurality of triangular surface elements, so as to determine a plurality of incident angles corresponding to the plurality of triangular surface elements according to the plurality of relative positional relationships; Determine backscatter coefficients corresponding to the plurality of triangular facets according to the plurality of incident angles, and determine echo amplitudes corresponding to the plurality of triangular facets according to the backscatter coefficients; Determine a transfer function according to the echo amplitude, and perform convolution on the transfer function to obtain a clutter signal; Calculating according to the illumination azimuth and the pitch angle to obtain a clutter area specifically includes: Determine an elliptical area illuminated by the antenna, determine terrain information corresponding to the elliptical area, and determine an area attribute of the elliptical area according to the terrain information; Determine a circumscribed rectangle corresponding to the elliptical area according to the area attribute, so as to determine the clutter area according to the circumscribed rectangle; Determining the echo amplitudes corresponding to the plurality of triangular facets according to the backscatter coefficients specifically includes: triangulate the clutter region to divide the planar object in the clutter region into a plurality of triangular face elements; Determine parameters corresponding to the plurality of triangular face elements, and perform calculations based on the parameters to obtain areas corresponding to the plurality of triangular face elements; Performing RCS calculation according to the areas corresponding to the plurality of triangular facets and the backscatter coefficient to determine the echo amplitude; Determine a plurality of centroids corresponding to the plurality of triangular facets, and determine the echo amplitudes of the plurality of centroids, wherein the calculation formula of the echo amplitude is: in, is the radar transmitting power, and are the transmitting antenna gains and the receiving antenna gains, is the radar operating wavelength, is the normalized scattering coefficient of the ith triangle surface element, is the area of ​​the ith triangle face, is the distance from the radar to the centroid of the triangle surface element, , , , is the coordinate of the centroid of the nth triangle element in the antenna coordinate system, is the radar system loss; The multiple distance unit indexes of the multiple centroids are calculated, and the calculation formula is: in, is the speed of light, is the sampling rate, represents the floor function; Determine the same items among the multiple distance unit indexes, and accumulate and sum the centroids corresponding to the same items to obtain the transfer function; Determine the transmit signal of the radar, which is expressed as: in, For time, is the carrier frequency, is the linear frequency modulation rate, B is the signal bandwidth, T is the pulse width, is a rectangular signal, , is the complex envelope of the signal, is the initial phase.

2. The method according to claim 1, characterized in that Determining backscattering coefficients corresponding to the plurality of triangular facets according to the plurality of incident angles specifically includes: Determining model parameters, the model parameters including but not limited to frequency, incident angle, and sea conditions; The model parameters are normalized, and a backscatter coefficient model is determined according to the processed model parameters, so as to determine the backscatter coefficient according to the backscatter coefficient model.

3. The method according to claim 1, characterized in that The method further comprises: The transmit signal and the transfer function are convolved to obtain the clutter signal.

4. A sea clutter simulation device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the sea clutter simulation device to perform: the method according to claim 1.

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