A ship bistatic RCS calculation method, device, equipment and storage medium

Abstract

The present application relates to the technical field of electromagnetic analysis, and discloses a ship double-station RCS calculation method, device, equipment and storage medium, which comprises the following steps: calculating the dielectric constant based on ship material parameters and sea surface physical parameters; calculating the incident wave and receiving wave propagation direction unit vector based on the spatial position coordinates of the transmitter and receiver; calculating the incident field amplitude based on the incident wave propagation direction unit vector; performing reflection analysis based on the ship-sea reflection path to obtain a ship-sea path reflection vector function, and calculating the ship-sea path reflection field amplitude in combination with the receiving wave propagation direction unit vector; calculating the first-station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude; and replacing the ship-sea reflection path with the sea-ship reflection path to calculate the second-station RCS data; the present application realizes more accurate RCS calculation by performing reflection analysis on the sea-ship reflection path and the ship-sea reflection path, and provides support for ship detection in complex marine scenarios.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic analysis technology, and in particular to a method, apparatus, equipment and storage medium for calculating the dual-station RCS of a ship. Background Technology

[0002] Despite some progress in existing ship radar cross section (RCS) calculation techniques, a key problem remains: existing technologies often cannot clearly distinguish the multiple reflection contributions between the ship and the sea surface, especially the calculation of dual reflection contributions (sea-ship and ship-sea reflections) is not accurate enough; this limitation leads to insufficient reliability of ship detection in complex marine scenarios. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, the present invention aims to provide a ship bistation RCS calculation method, apparatus, equipment, and storage medium. By clearly distinguishing the dual reflection contributions between the ship and the sea surface, it accurately analyzes the ship reflection path and the ship-sea reflection path, providing more accurate data support for RCS modeling and more reliable technical support for ship detection in complex marine scenarios.

[0004] The first aspect of this invention provides a bistatic RCS calculation method for ships, comprising: acquiring ship material parameters and sea surface physical parameters, and calculating the dielectric constant of the ship and the sea surface based on the ship material parameters and sea surface physical parameters; acquiring the spatial position coordinates of the transmitter and receiver and performing propagation vector calculation to obtain the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction; calculating the incident field amplitude based on the incident wave propagation direction unit vector; acquiring the ship-sea reflection path, performing reflection analysis based on the ship-sea reflection path, and calculating the reflection contribution in conjunction with the dielectric constant of the ship and the sea surface to obtain the ship-sea path reflection vector function; calculating the ship-sea path reflection field amplitude based on the received wave propagation direction unit vector and the ship-sea path reflection vector function; calculating the first-station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude; acquiring the ship reflection path, and using the ship reflection path as the ship-sea reflection path, returning to execute the step of performing reflection analysis based on the ship-sea reflection path to calculate the ship path reflection field amplitude, and calculating the second-station RCS data based on the incident field amplitude and the ship path reflection field amplitude.

[0005] Optionally, in a first implementation of the first aspect of the present invention, the step of calculating the dielectric constant of the ship and the sea surface based on the ship material parameters and the sea surface physical parameters includes: obtaining the ship material parameters and the sea surface physical parameters; inputting the ship material parameters and the sea surface physical parameters into a preset sea surface characteristic calculation model to calculate the dielectric constant of the ship and the sea surface.

[0006] Optionally, in a second implementation of the first aspect of the present invention, obtaining the spatial position coordinates of the transmitter and receiver and performing propagation vector calculation to obtain the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction includes: establishing a three-dimensional geometric coordinate system based on the ship; obtaining the spatial position coordinates of the transmitter and receiver in the three-dimensional geometric coordinate system; and calculating the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction based on the spatial position coordinates.

[0007] Optionally, in a third implementation of the first aspect of the present invention, the step of calculating the incident field amplitude based on the incident wave unit vector includes: obtaining the initial incident field amplitude and the incident field polarization direction unit vector; and calculating the incident field amplitude based on the incident wave propagation direction unit vector, the initial incident field amplitude, and the incident field polarization direction unit vector.

[0008] Optionally, in a fourth implementation of the first aspect of the present invention, the step of obtaining the ship-sea reflection path, performing reflection analysis based on the ship-sea reflection path, and calculating the reflection contribution in conjunction with the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function includes: the ship-sea reflection path includes a first reflection path from the transmitter to the ship hull and a second reflection path from the sea surface to the receiver; the ship-sea path reflection vector function includes a first ship-sea path reflection vector function and a second ship-sea path reflection vector function; the reflection coefficients of the first reflection path and the second reflection path are calculated based on the dielectric constants of the ship and the sea surface, respectively; the reflection contribution is calculated based on the reflection coefficient of the first reflection path and its corresponding polarization direction to obtain the first ship-sea path reflection vector function; and the reflection contribution is calculated based on the reflection coefficient of the second reflection path and its corresponding polarization direction to obtain the second ship-sea path reflection vector function.

[0009] Optionally, in a fifth implementation of the first aspect of the present invention, the step of calculating the amplitude of the ship-sea path reflection field based on the unit vector of the received wave propagation direction and the ship-sea path reflection vector function includes: calculating the total reflection vector function based on the ship-sea path reflection vector function; obtaining the sea surface reflection area and performing surface integration on the sea surface reflection area using the Monte Carlo method to obtain the surface integration result; and calculating the amplitude of the ship-sea path reflection field based on the unit vector of the received wave propagation direction, the total reflection vector function, and the surface integration result.

[0010] Optionally, in the sixth implementation of the first aspect of the present invention, the calculation of the first station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude includes: substituting the incident field amplitude and the ship-sea path reflection field amplitude into a preset RCS calculation formula, and performing calculation based on far-field conditions to obtain the first station RCS data.

[0011] A second aspect of this invention provides a ship bistatic RCS calculation device, comprising: a background analysis module for acquiring ship material parameters and sea surface physical parameters, and calculating the dielectric constant of the ship and the sea surface based on the ship material parameters and sea surface physical parameters; a wave vector calculation module for acquiring the spatial position coordinates of the transmitter and receiver and performing propagation vector calculation to obtain the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction; an incident field calculation module for calculating the incident field amplitude based on the unit vector of the incident wave propagation direction; and a reflection analysis module for acquiring the ship-sea reflection path, performing reflection analysis based on the ship-sea reflection path, and... The reflection contribution is calculated by combining the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function; the reflection field calculation module is used to calculate the ship-sea path reflection field amplitude based on the unit vector of the received wave propagation direction and the ship-sea path reflection vector function; the RCS calculation module is used to calculate the first station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude; the path switching module is used to obtain the ship's reflection path, use the ship's reflection path as the ship-sea reflection path, return to the reflection analysis module to calculate the ship path reflection field amplitude, and calculate the second station RCS data based on the incident field amplitude and the ship path reflection field amplitude.

[0012] A third aspect of the present invention provides a ship dual-station RCS calculation device, the ship dual-station RCS calculation device comprising: a memory and at least one processor, the memory storing instructions; at least one of the processors calling the instructions in the memory to cause the computer device to execute the various steps of the ship dual-station RCS calculation method described in any of the preceding claims.

[0013] A fourth aspect of the present invention provides a computer-readable storage medium storing instructions that, when executed by a processor, implement the steps of the ship bi-station RCS calculation method described in any of the preceding claims.

[0014] In the technical solution of this invention, the dielectric constants of the ship and the sea surface are first calculated based on the ship's material parameters and the sea surface's physical parameters, providing a physical basis for subsequent reflection contribution calculations. Next, the spatial coordinates of the transmitter and receiver are obtained and propagation vectors are calculated to determine the unit vectors of the incident and received wave propagation directions. Then, incident field modeling analysis is performed based on the unit vector of the incident wave propagation direction to obtain the incident field amplitude. Subsequently, reflection analysis is performed based on the ship-sea reflection path, and the reflection contribution is calculated in conjunction with the dielectric constants of the ship and the sea surface to determine the double reflection contribution during the ship-sea reflection stage. The reflection field is then modeled in conjunction with the unit vector of the received wave propagation direction to obtain the reflection field amplitude. The first station RCS data is calculated based on the incident field amplitude and the reflection field amplitude. After completing the first station RCS calculation, the ship-sea reflection path is reversed to the sea ship reflection path to calculate the second station RCS data. This invention, by clearly distinguishing the double reflection contribution between the ship and the sea surface, accurately analyzes the sea ship reflection path and the ship-sea reflection path, providing more accurate data support for RCS modeling and more reliable technical support for ship detection in complex marine scenarios. Attached Figure Description

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0016] Figure 1 This is a first flowchart of the ship dual-station RCS calculation method provided in the embodiments of the present invention;

[0017] Figure 2 This is a second flowchart of the ship dual-station RCS calculation method provided in the embodiments of the present invention;

[0018] Figure 3 This is a third flowchart of the ship dual-station RCS calculation method provided in the embodiments of the present invention;

[0019] Figure 4 This is a fourth flowchart of the ship dual-station RCS calculation method provided in the embodiments of the present invention;

[0020] Figure 5 The fifth flowchart of the ship dual-station RCS calculation method provided in the embodiments of the present invention;

[0021] Figure 6 The sixth flowchart of the ship dual-station RCS calculation method provided in the embodiments of the present invention;

[0022] Figure 7 The seventh flowchart of the ship bi-station RCS calculation method provided in the embodiments of the present invention;

[0023] Figure 8This is a schematic diagram of the structure of the ship dual-station RCS calculation device provided in an embodiment of the present invention;

[0024] Figure 9 This is a schematic diagram of the structure of a ship dual-station RCS calculation device provided in an embodiment of the present invention. Detailed Implementation

[0025] This invention provides a method, apparatus, device, and storage medium for calculating ship bistation RCS. By clearly distinguishing the contributions of single and double reflections between the ship and the sea surface, it accurately analyzes the ship's reflection path and the ship-sea reflection path, providing more accurate data support for RCS modeling and more reliable technical support for ship detection in complex marine scenarios.

[0026] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] For ease of understanding, the specific process of the embodiments of the present invention is described below. Please refer to [link / reference]. Figure 1 One embodiment of the ship dual-station RCS calculation method in this invention includes:

[0028] 101. Obtain ship material parameters and sea surface physical parameters, and calculate the dielectric constant of the ship and the sea surface based on the ship material parameters and sea surface physical parameters;

[0029] In this embodiment, the ship material parameters and sea surface physical parameters are first obtained. Then, these parameters are input into a preset sea surface characteristic calculation model to calculate the dielectric constant of the ship and the sea surface. This step provides the necessary physical basis for subsequent reflection contribution calculation.

[0030] 102. Obtain the spatial coordinates of the transmitter and receiver and calculate the propagation vector to obtain the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction;

[0031] In this embodiment, a three-dimensional geometric coordinate system based on the ship is first established to obtain the spatial position coordinates of the transmitter and receiver in the coordinate system. Then, the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction are calculated through normalization. This step clarifies the geometric relationship of the reflection path and provides the necessary geometric information for subsequent reflection field calculation.

[0032] 103. The amplitude of the incident field is calculated based on the unit vector of the incident wave propagation direction;

[0033] In this embodiment, the incident field amplitude can be calculated by substituting the unit vector of the incident wave propagation direction into the incident field modeling formula and combining it with the initial incident field amplitude.

[0034] 104. Obtain the ship-sea reflection path, perform reflection analysis based on the ship-sea reflection path, and calculate the reflection contribution by combining the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function.

[0035] In this embodiment, the ship-sea reflection path is first divided into a first reflection path from the transmitter to the ship hull and a second reflection path from the sea surface to the receiver. Then, reflection matrices are constructed and reflection vectors are calculated according to these two reflection paths to obtain the first reflection vector function and the second reflection vector function of the ship-sea path. This step ensures the accurate calculation of reflection contribution and provides the necessary reflection contribution information for subsequent reflection field calculation.

[0036] 105. The amplitude of the reflection field along the ship-sea path is calculated based on the unit vector of the received wave propagation direction and the reflection vector function of the ship-sea path.

[0037] In this embodiment, the amplitude of the reflection field along the ship-sea path can be calculated by substituting the unit vector of the received wave propagation direction, the first reflection vector function of the ship-sea path, and the second reflection vector function of the ship-sea path into the reflection field calculation formula.

[0038] 106. The RCS data of the first station was calculated based on the incident field amplitude and the reflection field amplitude of the ship-sea path.

[0039] In this embodiment, the incident field amplitude and the ship-sea path reflection field amplitude are substituted into the RCS calculation formula and calculated under far-field conditions to obtain the RCS data of the first station. This step ensures the accuracy of the RCS calculation and provides a reliable basis for the detection of ships in a multi-station remote sensing system.

[0040] 107. Obtain the reflection path of the sea vessel and use the sea vessel reflection path as the ship-sea reflection path. Return to the step of performing reflection analysis based on the ship-sea reflection path to calculate the amplitude of the sea vessel path reflection field. Calculate the RCS data of the second station based on the incident field amplitude and the sea vessel path reflection field amplitude.

[0041] In this embodiment, after calculating the RCS of the first station, it checks whether the RCS of the second station has been calculated. If it has not been calculated, the path reversal step continues.

[0042] Using the ship's reflection path as the ship-sea reflection path, that is, adjusting the reflection path order from the sea surface to the ship and then to the receiver; under a fixed bistatic geometry configuration (i.e., when the relative positions of the transmitter, receiver, and ship remain unchanged), the incident wave unit vector and the received wave unit vector in the two reflection paths (ship-sea reflection and ship-sea reflection) are the same, but the intermediate reflection directions are different; therefore, by reversing the path, it can be ensured that the contributions of the two reflection paths are accurately calculated.

[0043] After the path is reversed, steps 104 to 106 are repeated based on the reflection path of the ship. Reflection analysis is performed based on the new reflection path, and the RCS data of the second station can be calculated.

[0044] By using path reversal and repeated reflection analysis, the calculation of RCS data at the second station can be achieved, breaking through the limitations of single-station configuration and ensuring the integrity and accuracy of dual-station RCS calculation.

[0045] In this embodiment of the invention, the dielectric constants of the ship and the sea surface are first calculated based on the ship's material parameters and the sea surface's physical parameters, providing a physical basis for subsequent reflection contribution calculations. Next, the spatial coordinates of the transmitter and receiver are obtained and propagation vectors are calculated to determine the unit vectors of the incident and received wave propagation directions. Then, incident field modeling analysis is performed based on the unit vector of the incident wave propagation direction to obtain the incident field amplitude. Subsequently, reflection analysis is performed based on the ship-sea reflection path, and the reflection contribution is calculated in conjunction with the dielectric constants of the ship and the sea surface to determine the double reflection contribution during the ship-sea reflection stage. The reflection field is then modeled using the unit vector of the received wave propagation direction to obtain the reflection field amplitude. The first station RCS data is calculated based on the incident field amplitude and the reflection field amplitude. After completing the first station RCS calculation, the ship-sea reflection path is reversed to the ship's reflection path to calculate the second station RCS data. This invention, by clearly distinguishing the double reflection contribution between the ship and the sea surface, accurately analyzes the ship's reflection path and the ship-sea reflection path, providing more accurate data support for RCS modeling and more reliable technical support for ship detection in complex marine scenarios.

[0046] Please see Figure 2 Two embodiments of the ship dual-station RCS calculation method in this invention include step 101, which includes:

[0047] 201. Obtain ship material parameters and sea surface physical parameters;

[0048] In this embodiment, it is first necessary to obtain ship material parameters and sea surface physical parameters. Ship material parameters include the ship's material (such as steel, aluminum, composite materials, etc.), dimensions (such as length, width, height, etc.), and surface roughness. Sea surface physical parameters include sea surface salinity, temperature, wind speed, and sea surface roughness.

[0049] These parameters can be obtained through methods such as on-site measurement, historical data query, or laboratory testing; for example, salinity can be measured by using a salinity meter after seawater sampling, temperature can be measured by a temperature sensor, wind speed can be measured by an anemometer, and sea surface roughness can be estimated by remote sensing data or on-site observation.

[0050] 202. Input the ship material parameters and sea surface physical parameters into the preset sea surface property calculation model to calculate the dielectric constant of the ship and the sea surface;

[0051] In this embodiment, the obtained ship material parameters and sea surface physical parameters are input into a preset sea surface property calculation model to calculate the dielectric constant of the ship and the sea surface; the preset sea surface property calculation model can be the Klein-Swift model or other models suitable for calculating the dielectric constant of the sea surface.

[0052] By comprehensively considering various factors such as ship material composition, size, and sea conditions, the model is made to better fit the actual marine scene, thereby improving the accuracy of the dielectric constant; the accurate calculation of the dielectric constant ensures the accuracy of the reflection coefficient, thereby improving the reliability of RCS modeling.

[0053] Please see Figure 3 In the three embodiments of the ship dual-station RCS calculation method of the present invention, step 102 includes:

[0054] 301. Establish a three-dimensional geometric coordinate system based on the ship;

[0055] In this embodiment, it is first necessary to establish a three-dimensional geometric coordinate system based on the ship; the origin of this coordinate system can be set at the geometric center of the ship or at a location that is convenient for measurement and calculation.

[0056] 302. Obtain the spatial coordinates of the transmitter and receiver in a three-dimensional geometric coordinate system;

[0057] In this embodiment, the spatial coordinates of the transmitter and receiver in the coordinate system are obtained through GPS, radar, or other positioning devices; for example, ship coordinates can be defined. The transmitter coordinates can be initially defined as follows: The receiver coordinates can be initially defined as follows: .

[0058] 303. The unit vectors of the incident wave propagation direction and the received wave propagation direction are calculated based on the spatial position coordinates;

[0059] In this embodiment, the unit vectors of the incident wave propagation direction and the received wave propagation direction are calculated based on the spatial coordinates of the transmitter and receiver. The specific calculation method is as follows:

[0060] First, calculate the vector from the transmitter to the ship: ;

[0061] Then the vector from the transmitter to the ship... Normalization is performed to obtain the unit vector of the incident wave propagation direction. ;

[0062] Calculate the vector from the ship to the receiver: .

[0063] Vector from ship to receiver Normalization is performed to obtain the unit vector of the direction of wave propagation. ;

[0064] By following the steps above, the propagation direction unit vectors of the incident and received waves can be accurately determined, providing the necessary geometric information for subsequent calculations of the incident and reflected fields.

[0065] Please see Figure 4 In the four embodiments of the ship dual-station RCS calculation method in this invention, step 103 includes:

[0066] 401. Obtain the initial incident field amplitude and the unit vector of the incident field polarization direction;

[0067] In this embodiment, it is first necessary to obtain the initial incident field amplitude. and the unit vector of the polarization direction of the incident field Initial incident field amplitude The unit vector of the incident field polarization direction can be calculated using parameters such as the output power and antenna gain of the radar transmitter. It can be determined based on the polarization direction of the radar transmitter.

[0068] 402. The incident field amplitude is calculated based on the unit vector of the incident wave propagation direction, the initial incident field amplitude, and the unit vector of the incident field polarization direction.

[0069] In this embodiment, the unit vector of the incident wave propagation direction is used. Initial incident field amplitude and the unit vector of the polarization direction of the incident field The amplitude of the incident field is calculated based on the incident field formula. The incident field formula is as follows:

[0070] ;

[0071] in, For free space wavenumber, , Wavelength; The position vector of the observation point;

[0072] The imaginary unit is defined as satisfying The mathematical notation for electromagnetic fields; in engineering calculations related to electromagnetics and radar, it is standard practice to represent electric fields (or magnetic fields) in complex form because the propagation of electromagnetic waves simultaneously includes amplitude and phase information, while the imaginary unit... It is a key mathematical tool for constructing complex forms, thereby concisely describing the phase variation with spatial position, and can accurately reflect the wave characteristics of electromagnetic waves;

[0073] By following the steps above, the incident field amplitude can be accurately calculated, providing the necessary initial conditions for subsequent RCS calculations.

[0074] Please see Figure 5 Five embodiments of the ship dual-station RCS calculation method in this invention include step 104, which includes:

[0075] The ship-sea reflection path includes a first reflection path from the transmitter to the ship hull and a second reflection path from the sea surface to the receiver; the ship-sea path reflection vector function includes a first ship-sea path reflection vector function and a second ship-sea path reflection vector function.

[0076] 501. Calculate the reflection coefficients of the first and second reflection paths based on the dielectric constants of the ship and the sea surface, respectively;

[0077] In this embodiment, the reflection coefficients of the first reflection path and the second reflection path are calculated using the dielectric constants of the ship and the sea surface, respectively.

[0078] The formula for calculating the reflection coefficient is as follows: In the formula, The reflection coefficient, It is the dielectric constant;

[0079] For the first reflection path (from transmitter to hull), the first reflection coefficient It can be based on the dielectric constant of the ship. The calculations show that, for the second reflection path (from the sea surface to the receiver), the second reflection coefficient is... It can be determined based on the dielectric constant of the sea surface. Calculated.

[0080] 502. Calculate the reflection contribution based on the reflection coefficient of the first reflection path and its corresponding polarization direction to obtain the first reflection vector function of the ship-sea path;

[0081] In this embodiment, a reflection matrix is ​​constructed based on the reflection coefficient of the first reflection path and its corresponding polarization direction, and the first reflection vector function of the ship-sea path is calculated by combining the geometric optics approximation.

[0082] The elements of the first reflection matrix are defined as follows:

[0083] ;

[0084] ;

[0085] in, These are the matrix elements of the first reflection matrix. and These correspond to horizontal and vertical polarization, respectively. It is the identity matrix; The polarization direction of the reflected wave is represented by a unit vector.

[0086] In the formula, It is a 3x3 identity matrix (the elements on the diagonal are 1s and the elements off the diagonal are 0s). It is the unit vector of the reflected wave (three-dimensional vector). It is the outer product of vectors (represented as a 3x3 matrix); in electromagnetic scattering calculations, This is the classic "transverse wave projection operator," whose function is to eliminate waves parallel to... The component, only those perpendicular to The transverse wave amplitude is calculated to ensure that subsequent calculation results conform to the transverse wave characteristics of the electromagnetic field.

[0087] Let be the first reflection vector function. The vector function describing the reflection direction of the first reflection field contains the unit vector of the incident wave propagation direction. Unit vector of incident wave polarization direction and surface normal unit vector The effect on the direction of the reflection field; since the reflection path is from the transmitter to the hull, the surface normal vector is a unit vector. Take the unit vector of the hull surface normal.

[0088] 503. Calculate the reflection contribution based on the reflection coefficient of the second reflection path and its corresponding polarization direction to obtain the second reflection vector function of the ship-sea path;

[0089] In this embodiment, a reflection matrix is ​​constructed based on the reflection coefficient of the second reflection path and its corresponding polarization direction, and the second reflection vector function of the ship-sea path is calculated by combining the geometric optics approximation.

[0090] The elements of the second reflection matrix are defined as follows:

[0091] ;

[0092] ;

[0093] in, These are the matrix elements of the second reflection matrix. This is the second reflection vector function. The vector function describing the direction of reflection of the first reflection field contains the unit wave vector incident on the sea surface. The unit vector of polarization direction incident on the sea surface and surface normal unit vector Influence on the direction of the reflected field;

[0094] That is, the unit wave vector pointing towards the sea surface after reflection from the ship's hull, which is determined by the reflected wave vector of the first reflection path; specifically, in the first reflection path, according to the specular reflection condition, combined with the unit vector of the incident wave propagation direction. and surface normal vector unit vector The first reflected wave vector, i.e., the unit wave vector incident on the sea surface, can be calculated. ;

[0095] Similarly, It is the unit vector of polarization direction incident on the sea surface, that is, the unit vector of polarization direction of the incident wave in the second reflection path, which is determined by the polarization direction of the reflected wave in the first reflection path; specifically, in the first reflection path, according to the unit vector of polarization direction of the incident wave... The unit vector of polarization direction of the reflected wave can be calculated, that is, the unit vector of polarization direction incident on the sea surface. ;

[0096] At the same time, since the reflection path at this time is from the transmitter to the hull, the surface normal vector is a unit vector. Take the unit vector as the surface normal of the sea.

[0097] Please see Figure 6 The six embodiments of the ship dual-station RCS calculation method in this invention include step 105, which includes:

[0098] 601. The total reflection vector function is calculated based on the ship-sea path reflection vector function;

[0099] In this embodiment, the first reflection vector function of the ship-sea path is extracted from the ship-sea path reflection vector function. Second reflection vector function of ship-sea path and the first reflection vector function Second reflection vector function of ship-sea path Perform matrix operations to obtain the total reflection vector function. ;

[0100] ;

[0101] The total reflection matrix can be obtained by performing a non-commutative product operation on the first and second reflection matrices. The non-commutative product reflects the order of the two reflection processes, that is, the first reflection occurs first (from the transmitter to the ship), and then the second reflection occurs (from the sea surface to the receiver).

[0102] 602. Obtain the sea surface reflection area and use the Monte Carlo method to perform surface integration on the sea surface reflection area to obtain the surface integration result;

[0103] In this embodiment, the calculation steps for the surface integral result are as follows:

[0104] First, multiple points were randomly sampled within the sea surface reflection integration region S. To ensure the accuracy and reliability of the integration results, at least 10 independent sampling experiments were conducted. Subsequently, for each sampling point, the unit vector of the incident wave propagation direction was calculated. Unit vector relative to the direction of received wave propagation The difference is calculated, and the position vector of each sampling point is obtained. It should be noted that during the sampling process, the shading effect of ships should be considered, and sampling points in shadowed areas should be excluded. Finally, the contribution of all valid sampling points is integrated to obtain the sea surface reflection integral result.

[0105] The expression for the integral result of sea surface reflection is as follows:

[0106] ;

[0107] In the formula, ; It is the imaginary unit, used to represent the phase change of electromagnetic waves.

[0108] 603. The amplitude of the reflection field along the ship-sea path is calculated based on the unit vector of the received wave propagation direction, the total reflection vector function, and the surface integral results;

[0109] In this embodiment, the amplitude of the reflection field along the ship-sea path can be calculated based on the reflection field modeling formula:

[0110] ;

[0111] in, The amplitude of the reflected field. It is the Euclidean distance from the observation point to the reflecting surface.

[0112] Please see Figure 7 The seven embodiments of the ship dual-station RCS calculation method in this invention include step 106, which includes:

[0113] 701. Substitute the incident field amplitude and the ship-sea path reflection field amplitude into the preset RCS calculation formula, and perform calculation based on the far-field conditions to obtain the RCS data of the first station.

[0114] In this embodiment, the incident field amplitude and the reflected field amplitude are substituted into the preset RCS calculation formula, and the calculation is performed based on the far-field conditions to obtain the RCS data of the first station, as follows:

[0115] ;

[0116] RCS refers to the RCS data; the far-field condition assumes that the reflected field propagates in the far-field region as a spherical wave, thus simplifying the calculation.

[0117] The above describes the ship bistatic RCS calculation method in the embodiments of the present invention. The following describes the ship bistatic RCS calculation device in the embodiments of the present invention. Please refer to [link / reference]. Figure 8 One embodiment of the ship dual-station RCS calculation device in this invention includes:

[0118] Background analysis module 801 is used to obtain ship material parameters and sea surface physical parameters, and calculate the dielectric constant of the ship and the sea surface based on the ship material parameters and sea surface physical parameters;

[0119] The wave vector calculation module 802 is used to obtain the spatial position coordinates of the transmitter and receiver and perform propagation vector calculation to obtain the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction;

[0120] The incident field calculation module 803 is used to calculate the incident field amplitude based on the unit vector of the incident wave propagation direction.

[0121] The reflection analysis module 804 is used to obtain the ship-sea reflection path, perform reflection analysis based on the ship-sea reflection path, and calculate the reflection contribution by combining the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function.

[0122] The reflection field calculation module 805 is used to calculate the amplitude of the reflection field along the ship and sea path based on the unit vector of the received wave propagation direction and the ship-sea path reflection vector function.

[0123] RCS calculation module 806 is used to calculate the first station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude.

[0124] The path switching module 807 is used to obtain the reflection path of the sea vessel and use the sea vessel reflection path as the ship-sea reflection path, and return it to the reflection analysis module 804 to calculate the amplitude of the sea vessel path reflection field, and calculate the RCS data of the second station based on the incident field amplitude and the sea vessel path reflection field amplitude.

[0125] In this embodiment, the background analysis module 801 calculates the dielectric constants of the ship and the sea surface based on the ship's material parameters and the sea surface's physical parameters. Next, the wave vector calculation module 802 obtains the spatial coordinates of the transmitter and receiver and performs propagation vector calculations to determine the unit vectors of the incident and received wave propagation directions. Then, the incident field calculation module 803 performs incident field modeling analysis based on the unit vector of the incident wave propagation direction to obtain the incident field amplitude. Subsequently, the reflection analysis module 804 performs reflection analysis based on the ship-sea reflection path, calculates the reflection contribution by combining the dielectric constants of the ship and the sea surface, and determines the double reflection contribution during the ship-sea reflection stage. Finally, the reflection field calculation module 805 combines the first reflection vector function, the second reflection vector, and the unit vector of the received wave propagation direction to model the reflection field and obtain the reflection... The RCS calculation module 806 calculates the first station's RCS data based on the incident field amplitude and the reflected field amplitude. After completing the first station's RCS calculation, the path switching module 807 reverses the ship-sea reflection path to the ship's reflection path and returns to the reflection analysis module 804. Using the ship's reflection path as the analysis basis, the ship's path reflection vector function is recalculated. Then, the reflection field calculation module 805 calculates the ship's path reflection field amplitude, and finally, the RCS calculation module 806 calculates the second station's RCS data again. This invention, by clearly distinguishing the dual reflection contribution between the ship and the sea surface, accurately analyzes the ship's reflection path and the ship-sea reflection path, providing more accurate data support for RCS modeling and more reliable technical support for ship detection in complex marine scenarios.

[0126] Figure 9This is a schematic diagram of a ship dual-station RCS calculation device 900 provided in an embodiment of the present invention. The ship dual-station RCS calculation device 900 can vary significantly due to different configurations or performance. It may include one or more central processing units (CPUs) 910 (e.g., one or more processors) and a memory 920, and one or more storage media 930 (e.g., one or more mass storage devices) storing application programs 933 or data 932. The memory 920 and storage media 930 can be temporary or persistent storage. The program stored in the storage media 930 may include one or more modules (not shown in the diagram), each module may include a series of instruction operations on the ship dual-station RCS calculation device 900. Furthermore, the processor 910 may be configured to communicate with the storage media 930 and execute the series of instruction operations in the storage media 930 on the ship dual-station RCS calculation device 900 to implement the steps of the ship dual-station RCS calculation method provided in the above-described method embodiments.

[0127] The shipboard dual-station RCS computing device 900 may also include one or more power supplies 940, one or more wired or wireless network interfaces 950, one or more input / output interfaces 960, and / or one or more operating systems 931, such as Windows Server, Mac OS X, Unix, Linux, FreeBSD, etc. Those skilled in the art will understand that... Figure 9 The illustrated structure of a ship bistation RCS calculation device does not constitute a limitation on the ship bistation RCS calculation device. It may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0128] The present invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the steps of the ship bi-station RCS calculation method.

[0129] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system, device, or unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0130] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0131] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for calculating the RCS of a ship using bistationary stations, characterized in that, include: Obtain ship material parameters and sea surface physical parameters, and calculate the dielectric constant of the ship and the sea surface based on the ship material parameters and sea surface physical parameters; Obtain the spatial coordinates of the transmitter and receiver and calculate the propagation vector to obtain the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction; The amplitude of the incident field is calculated based on the unit vector of the incident wave propagation direction. The ship-sea reflection path is obtained, reflection analysis is performed based on the ship-sea reflection path, and the reflection contribution is calculated by combining the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function. The amplitude of the reflection field along the ship and sea path is calculated based on the unit vector of the received wave propagation direction and the reflection vector function of the ship and sea path. The RCS data of the first station was calculated based on the incident field amplitude and the reflection field amplitude of the ship-sea path. Obtain the reflection path of the sea vessel and use it as the sea-ship reflection path. Return to the step of performing reflection analysis based on the sea-ship reflection path to calculate the amplitude of the sea vessel path reflection field. Calculate the RCS data of the second station based on the incident field amplitude and the sea vessel path reflection field amplitude. The process of obtaining the ship-sea reflection path, performing reflection analysis based on the ship-sea reflection path, and calculating the reflection contribution by combining the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function includes: the ship-sea reflection path includes a first reflection path from the transmitter to the ship hull and a second reflection path from the sea surface to the receiver; the ship-sea path reflection vector function includes a first reflection vector function and a second reflection vector function; the reflection coefficients of the first and second reflection paths are calculated based on the dielectric constants of the ship and the sea surface, respectively; the reflection contribution is calculated based on the reflection coefficient of the first reflection path and its corresponding polarization direction to obtain the first reflection vector function of the ship-sea path; and the reflection contribution is calculated based on the reflection coefficient of the second reflection path and its corresponding polarization direction to obtain the second reflection vector function of the ship-sea path.

2. The ship bistation RCS calculation method according to claim 1, characterized in that, The dielectric constant of the ship and the sea surface calculated based on ship material parameters and sea surface physical parameters includes: Obtain ship material parameters and sea surface physical parameters; The ship's material parameters and the sea surface's physical parameters are input into a preset sea surface property calculation model to calculate the dielectric constant of the ship and the sea surface.

3. The ship bistation RCS calculation method according to claim 1, characterized in that, The process of obtaining the spatial coordinates of the transmitter and receiver and calculating the propagation vectors to obtain the unit vectors of the incident wave propagation direction and the received wave propagation direction includes: Establish a three-dimensional geometric coordinate system based on the ship; Obtain the spatial coordinates of the transmitter and receiver in a three-dimensional geometric coordinate system; The unit vectors of the incident wave propagation direction and the received wave propagation direction are calculated based on the spatial location coordinates.

4. The ship bistation RCS calculation method according to claim 1, characterized in that, The incident field amplitude calculated based on the unit vector of the incident wave propagation direction includes: Obtain the initial incident field amplitude and the unit vector of the incident field polarization direction; The incident field amplitude is calculated based on the unit vector of the incident wave propagation direction, the initial incident field amplitude, and the unit vector of the incident field polarization direction.

5. The ship bistation RCS calculation method according to claim 1, characterized in that, The amplitude of the ship-sea path reflection field calculated based on the unit vector of the received wave propagation direction and the ship-sea path reflection vector function includes: The total reflection vector function is calculated based on the ship-sea path reflection vector function; The sea surface reflection area is obtained, and the surface integration of the sea surface reflection area is performed using the Monte Carlo method to obtain the surface integration result; The amplitude of the reflection field along the ship-sea path is calculated based on the unit vector of the received wave propagation direction, the total reflection vector function, and the surface integral results.

6. The ship bistation RCS calculation method according to claim 1, characterized in that, The RCS data for the first station, calculated based on the incident field amplitude and the ship-sea path reflection field amplitude, includes: The incident field amplitude and the ship-sea path reflection field amplitude are substituted into the preset RCS calculation formula and calculated based on the far-field conditions to obtain the RCS data of the first station.

7. A ship dual-station RCS calculation device, characterized in that, include: The background analysis module is used to obtain ship material parameters and sea surface physical parameters, and calculate the dielectric constant of the ship and the sea surface based on the ship material parameters and sea surface physical parameters; The wave vector calculation module is used to obtain the spatial position coordinates of the transmitter and receiver and perform propagation vector calculation to obtain the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction. The incident field calculation module is used to calculate the incident field amplitude based on the unit vector of the incident wave propagation direction. The reflection analysis module is used to acquire the ship-sea reflection path, perform reflection analysis based on the reflection path, and calculate the reflection contribution by combining the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function. The acquisition of the ship-sea reflection path, the reflection analysis based on the ship-sea reflection path, and the calculation of the reflection contribution by combining the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function include: the ship-sea reflection path includes a first reflection path from the transmitter to the ship hull and a second reflection path from the sea surface to the receiver; the ship-sea path reflection vector function includes a first reflection vector function and a second reflection vector function; the reflection coefficients of the first and second reflection paths are calculated based on the dielectric constants of the ship and the sea surface, respectively; the reflection contribution is calculated based on the reflection coefficient of the first reflection path and its corresponding polarization direction to obtain the first reflection vector function of the ship-sea path; the reflection contribution is calculated based on the reflection coefficient of the second reflection path and its corresponding polarization direction to obtain the second reflection vector function of the ship-sea path. The reflection field calculation module is used to calculate the amplitude of the reflection field along the ship and sea path based on the unit vector of the received wave propagation direction and the reflection vector function of the ship and sea path. The RCS calculation module is used to calculate the RCS data of the first station based on the incident field amplitude and the reflection field amplitude of the ship-sea path. The path switching module is used to obtain the reflection path of the sea vessel and use the sea vessel reflection path as the ship-sea reflection path. It then returns to the reflection analysis module to calculate the amplitude of the sea vessel path reflection field and calculates the RCS data of the second station based on the incident field amplitude and the sea vessel path reflection field amplitude.

8. A ship dual-station RCS calculation device, characterized in that, The ship dual-station RCS computing device includes: a memory and at least one processor, wherein the memory stores instructions; At least one of the processors invokes the instructions in the memory to cause the ship bi-station RCS calculation device to perform the various steps of the ship bi-station RCS calculation method as described in any one of claims 1-6.

9. A computer-readable storage medium storing instructions thereon, characterized in that, When the instructions are executed by the processor, they implement the various steps of the ship bistation RCS calculation method as described in any one of claims 1-6.

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