Ship double-station RCS calculation method, device and equipment and storage medium

Abstract

The invention relates to the technical field of electromagnetic analysis, and discloses a ship double-station RCS calculation method, device and equipment and a storage medium, and the method comprises the steps: calculating a dielectric constant based on ship material parameters and sea surface physical parameters; based on the spatial position coordinates of the transmitter and the receiver, the propagation direction unit vectors of the incident wave and the received wave are calculated; the incident field amplitude is calculated based on the incident wave propagation direction unit vector; reflection analysis is carried out based on the ship-sea reflection path, a ship-sea path reflection vector function is obtained, and a ship-sea path reflection field amplitude is obtained through calculation in combination with a received wave propagation direction unit vector; calculating first station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude; replacing the ship-sea reflection path with a ship reflection path, and calculating to obtain second station RCS data; according to the method, the ship reflection path and the ship-sea reflection path are subjected to reflection analysis, so that more accurate RCS calculation is realized, and support is provided for ship detection in a complex ocean scene.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic analysis, and particularly relates to a ship bistatic RCS calculation method, device, equipment and storage medium. BACKGROUND

[0002] In the existing ship radar cross section (RCS) calculation technology, although certain progress has been made, there is still a key problem: the existing technology usually cannot clearly distinguish the multiple reflection contributions between the ship and the sea surface, especially the calculation of double reflection contributions (sea-ship, ship-sea reflection) is not accurate enough; such limitation leads to insufficient reliability of ship detection in complex marine scenarios. SUMMARY

[0003] In order to overcome the deficiencies of the prior art, the purpose of the present application is to provide a ship bistatic RCS calculation method, device, equipment and storage medium, which clearly distinguishes the double reflection contributions between the ship and the sea surface, accurately analyzes the sea-ship reflection path and the ship-sea reflection path, provides more accurate data support for RCS modeling, and provides more reliable technical support for ship detection in complex marine scenarios.

[0004] The first aspect of the present application provides a ship bistatic RCS calculation method, comprising: obtaining 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 the sea surface physical parameters; obtaining the spatial position coordinates of the transmitter and the receiver and performing propagation vector calculation to obtain the incident wave propagation direction unit vector and the received wave propagation direction unit vector; calculating the incident field amplitude based on the incident wave propagation direction unit vector; obtaining the ship-sea reflection path, performing reflection analysis based on the ship-sea reflection path, and combining the dielectric constant of the ship and the sea surface to perform reflection contribution calculation 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; obtaining the sea-ship reflection path, taking the sea-ship reflection path as the ship-sea reflection path, returning to perform the step of reflection analysis based on the ship-sea reflection path to calculate the sea-ship path reflection field amplitude, and calculating the second station RCS data based on the incident field amplitude and the sea-ship path reflection field amplitude.

[0005] Optionally, in the first implementation manner of the first aspect of the present application, the calculation of the dielectric constant of the ship and the sea surface based on the ship material parameters and the sea surface physical parameters comprises: 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 the second implementation form of the first aspect of the present application, the method further comprises: establishing a three-dimensional geometric coordinate system with the ship as a reference; obtaining the spatial position coordinates of the transmitter and the receiver in the three-dimensional geometric coordinate system; and calculating the incident wave propagation direction unit vector and the received wave propagation direction unit vector based on the spatial position coordinates.

[0007] Optionally, in the third implementation form of the first aspect of the present application, the method further comprises: obtaining an initial incident field amplitude and an 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 the fourth implementation form of the first aspect of the present application, the method further comprises: the ship-sea reflection path comprises a first reflection path from the transmitter to the ship body and a second reflection path from the sea surface to the receiver; the ship-sea path reflection vector function comprises a ship-sea path first reflection vector function and a ship-sea path second reflection vector function; calculating the reflection coefficients of the first reflection path and the second reflection path based on the dielectric constants of the ship and the sea surface; calculating the reflection contribution of the first reflection path based on the reflection coefficient of the first reflection path and the corresponding polarization direction to obtain the ship-sea path first reflection vector function; and calculating the reflection contribution of the second reflection path based on the reflection coefficient of the second reflection path and the corresponding polarization direction to obtain the ship-sea path second reflection vector function.

[0009] Optionally, in the fifth implementation form of the first aspect of the present application, the method further comprises: calculating a total reflection vector function based on the ship-sea path reflection vector function; obtaining a sea surface reflection region and performing a surface integral on the sea surface reflection region by using a Monte Carlo method to obtain a surface integral result; and calculating the ship-sea path reflection field amplitude based on the received wave propagation direction unit vector, the total reflection vector function and the surface integral result.

[0010] Optionally, in the sixth implementation form of the first aspect of the present application, the method further comprises: substituting the incident field amplitude and the ship-sea path reflection field amplitude into a preset RCS calculation formula, and calculating based on a far field condition to obtain the first station RCS data.

[0011] The second aspect of the present application provides a ship bistatic RCS calculation device, comprising: a background analysis module, configured 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 the sea surface physical parameters; a wave vector calculation module, configured to obtain the spatial position coordinates of a transmitter and a receiver and perform propagation vector calculation to obtain an incident wave propagation direction unit vector and a received wave propagation direction unit vector; an incident field calculation module, configured to calculate an incident field amplitude based on the incident wave propagation direction unit vector; a reflection analysis module, configured to obtain a ship-sea reflection path, perform reflection analysis based on the ship-sea reflection path, and perform reflection contribution calculation in combination with the dielectric constant of the ship and the sea surface to obtain a ship-sea path reflection vector function; a reflection field calculation module, configured to calculate a ship-sea path reflection field amplitude based on the received wave propagation direction unit vector and the ship-sea path reflection vector function; an RCS calculation module, configured to calculate first station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude; and a path switching module, configured to obtain a sea-ship reflection path, take the sea-ship reflection path as the ship-sea reflection path, return the reflection analysis module, calculate a sea-ship path reflection field amplitude, and calculate second station RCS data based on the incident field amplitude and the sea-ship path reflection field amplitude.

[0012] The third aspect of the present application provides a ship bistatic RCS calculation device, comprising: a memory and at least one processor, wherein the memory stores instructions; and the at least one processor invokes the instructions in the memory to enable the computer device to perform the steps of the ship bistatic RCS calculation method according to any one of the above aspects.

[0013] The fourth aspect of the present application provides a computer readable storage medium, wherein the computer readable storage medium stores instructions, and the instructions are executed by a processor to implement the steps of the ship bistatic RCS calculation method according to any one of the above aspects.

[0014] In the technical solution of the application, firstly, the dielectric constant of the ship and the sea surface is calculated based on the ship material parameters and the sea surface physical parameters, which provides a physical basis for subsequent reflection contribution calculation; then, the spatial position coordinates of the transmitter and the receiver are obtained and the propagation vector calculation is performed to determine the unit vectors of the incident wave and the receiving wave propagation direction; then, the incident field modeling analysis is performed based on the incident wave propagation direction unit vector to obtain the incident field amplitude; subsequently, the reflection analysis is performed based on the ship-sea reflection path, the reflection contribution calculation is performed in combination with the dielectric constant of the ship and the sea surface, the double reflection contribution in the ship-sea reflection stage is determined, and the reflection field modeling is performed in combination with the receiving wave propagation direction unit vector 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 the first station RCS calculation is completed, the ship-sea reflection path is reversed to the sea-ship reflection path to calculate the second station RCS data; the application clearly distinguishes the double reflection contribution between the ship and the sea surface, accurately analyzes the sea-ship reflection path and the ship-sea reflection path, provides more accurate data support for RCS modeling, and provides more reliable technical support for ship detection in complex ocean scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which: Figure 1 The first flow chart of the ship bistatic RCS calculation method provided by the embodiment of the application; Figure 2 The second flow chart of the ship bistatic RCS calculation method provided by the embodiment of the application; Figure 3 The third flow chart of the ship bistatic RCS calculation method provided by the embodiment of the application; Figure 4 The fourth flow chart of the ship bistatic RCS calculation method provided by the embodiment of the application; Figure 5 The fifth flow chart of the ship bistatic RCS calculation method provided by the embodiment of the application; Figure 6 The sixth flow chart of the ship bistatic RCS calculation method provided by the embodiment of the application; Figure 7 The seventh flow chart of the ship bistatic RCS calculation method provided by the embodiment of the application; Figure 8 The structure schematic diagram of the ship bistatic RCS calculation device provided by the embodiment of the application; Figure 9 The structure schematic diagram of the ship bistatic RCS calculation device provided by the embodiment of the application; DETAILED DESCRIPTION

[0016] The application provides a ship bistatic RCS calculation method, device, equipment and storage medium, which clearly distinguiates single reflection and double reflection contribution between a ship and a sea surface, accurately analyzes a ship reflection path and a ship-sea reflection path, provides more accurate data support for RCS modeling, and provides more reliable technical support for ship detection in a complex marine scene.

[0017] The terms "first", "second", "third", "fourth" and the like in the description and claims of the application, and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of these terms herein is to be construed as interchangeable in order to comfort the embodiments described herein with other embodiments described herein other than the one that is being referred to. Furthermore, the terms "comprising", "having", "including", and the like, when used in the present specification, are used in their inclusive sense and not in an exclusive sense. That is, unless otherwise noted, the terms "comprising" and "including" when used in the present description and claims, specify the presence of stated features or steps, but do not preclude the presence or addition of one or more other features or steps.

[0018] For the convenience of understanding, the specific flow of the embodiments of the application is described below. Please refer to Figure 1 One embodiment of the ship bistatic RCS calculation method in the embodiments of the application includes the following steps. 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 the sea surface physical parameters; In this embodiment, first, the ship material parameters and the sea surface physical parameters are obtained, and then the 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 the subsequent reflection contribution calculation.

[0019] 102, obtain the spatial position coordinates of the transmitter and the receiver and perform propagation vector calculation to obtain an incident wave propagation direction unit vector and a received wave propagation direction unit vector; In this embodiment, a three-dimensional geometric coordinate system with the ship as the reference is established to obtain the spatial position coordinates of the transmitter and the receiver in the coordinate system. Then, the incident wave propagation direction unit vector and the received wave propagation direction unit vector are calculated through normalization processing. This step clearly defines the geometric relationship of the reflection path and provides the necessary geometric information for the subsequent reflection field calculation.

[0020] 103, calculate the incident field amplitude based on the incident wave propagation direction unit vector; In this embodiment, the incident wave propagation direction unit vector is substituted into the incident field modeling formula, and the initial incident field amplitude is combined to calculate the incident field amplitude.

[0021] 104. Obtain the ship-sea reflection path, perform reflection analysis based on the ship-sea reflection path, and calculate the reflection contribution in combination with the dielectric constants of the ship and the sea surface to obtain a ship-sea path reflection vector function; In this embodiment, the ship-sea reflection path is first specifically split into a first reflection path from the transmitter to the ship body and a second reflection path from the sea surface to the receiver. Then, reflection matrix construction and reflection vector calculation are performed according to the two reflection paths respectively to obtain a ship-sea path first reflection vector function and a ship-sea path second reflection vector function. This step ensures accurate calculation of the reflection contribution and provides necessary reflection contribution information for subsequent reflection field calculation.

[0022] 105. Calculate the ship-sea path reflection field amplitude based on the receiving wave propagation direction unit vector and the ship-sea path reflection vector function; In this embodiment, the receiving wave propagation direction unit vector, the ship-sea path first reflection vector function, and the ship-sea path second reflection vector function are substituted into the reflection field calculation formula to calculate the ship-sea path reflection field amplitude.

[0023] 106. Calculate the first station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude; In this embodiment, the incident field amplitude and the ship-sea path reflection field amplitude are substituted into the RCS calculation formula, and the calculation is performed under the condition of far field to obtain the first station RCS data. This step ensures the accuracy of RCS calculation and provides a reliable basis for detection of the ship in a multi-station remote sensing system.

[0024] 107. Obtain the sea-ship reflection path, and take the sea-ship reflection path as the ship-sea reflection path to return to the step of performing reflection analysis based on the ship-sea reflection path to calculate the sea-ship path reflection field amplitude, and calculate the second station RCS data based on the incident field amplitude and the sea-ship path reflection field amplitude; In this embodiment, after completing the first station RCS calculation, it is checked whether the second station RCS has been calculated. If not, the path inversion step is continued: The sea-ship reflection path is taken as the ship-sea reflection path, that is, the reflection path order is adjusted from the sea surface to the ship body and then to the receiver. In a fixed bistatic geometry configuration (i.e., when the relative positions of the transmitter, receiver, and ship do not change), the incident unit vector and the receiving unit vector in the two reflection paths (ship-sea reflection and sea-ship reflection) are the same, but the intermediate reflection direction is different. Therefore, through path inversion, the contributions of the two reflection paths can be accurately calculated; After path reversal, steps 104 to 106 are repeated based on the sea-ship reflection path, and reflection analysis is performed based on the new reflection path, so that the second station RCS data can be calculated; Through path reversal and repeated reflection analysis, the calculation of the second station RCS data can be realized, the limitation of single station configuration is broken through, and the integrity and accuracy of the double station RCS calculation are ensured.

[0025] In the embodiment of the present application, first, the dielectric constant of the ship and the sea surface is calculated based on the ship material parameters and the sea surface physical parameters, which provides a physical basis for subsequent reflection contribution calculation; then, the spatial position coordinates of the transmitter and the receiver are obtained and the propagation vector calculation is performed, and the unit vectors of the incident wave and the receiving wave propagation direction are determined; then, the incident field modeling analysis is performed based on the incident wave propagation direction unit vector to obtain the incident field amplitude; subsequently, reflection analysis is performed based on the ship-sea reflection path, and reflection contribution calculation is performed in combination with the dielectric constant of the ship and the sea surface, the double reflection contribution in the ship-sea reflection stage is determined, and the reflection field modeling is performed in combination with the receiving wave propagation direction unit vector 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 the first station RCS calculation is completed, the ship-sea reflection path is reversed to the sea-ship reflection path to calculate the second station RCS data; the present application clearly distinguishes the double reflection contribution between the ship and the sea surface, accurately analyzes the sea-ship reflection path and the ship-sea reflection path, provides more accurate data support for RCS modeling, and provides more reliable technical support for ship detection in complex marine scenarios.

[0026] Please refer to Figure 2 In the two embodiments of the ship double station RCS calculation method in the embodiment of the present application, step 101 comprises: 201, obtaining ship material parameters and sea surface physical parameters; In this embodiment, first, the ship material parameters and the sea surface physical parameters need to be obtained; the ship material parameters include the material of the ship (such as steel, aluminum, composite material, etc.), the size (such as length, width, height, etc.) and the surface roughness, etc.; the sea surface physical parameters include the salinity, temperature, wind speed of the sea surface and the roughness of the sea surface, etc.; These parameters can be obtained by field measurement, historical data query or laboratory test, etc.; for example, the salinity can be measured by sampling seawater and using a salinity meter, the temperature can be measured by a temperature sensor, the wind speed can be measured by a wind speed meter, and the sea surface roughness can be estimated by remote sensing data or field observation.

[0027] 202, 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; In this embodiment, the obtained ship material parameters and sea surface physical parameters are input into a preset sea surface characteristic calculation model to calculate the dielectric constant between the ship and the sea surface; the preset sea surface characteristic calculation model can adopt the Klein-Swift model or other models suitable for calculating the dielectric constant of the sea surface; By comprehensively considering various factors such as ship material composition, size, and sea conditions, the model is made more consistent with actual ocean scenarios, thereby improving the accuracy of the dielectric constant; the precise calculation of the dielectric constant ensures the accuracy of the reflection coefficient, thereby improving the reliability of RCS modeling.

[0028] See also Figure 3 In the three embodiments of the ship dual-station RCS calculation method according to the present invention, step 102 includes: 301. Establish a three-dimensional geometric coordinate system based on the ship; In this embodiment, it is first necessary to establish a three-dimensional geometric coordinate system based on the ship; the origin of the coordinate system can be set at the geometric center of the ship or a position that is convenient for measurement and calculation.

[0029] 302. Obtain spatial position coordinates of the transmitter and the receiver in a three-dimensional geometric coordinate system; In this embodiment, the spatial position coordinates of the transmitter and the receiver in the coordinate system are obtained by GPS, radar or other positioning equipment; for example, the coordinates of a ship can be defined as The transmitter coordinates can be preliminarily defined as , the receiver coordinates can be preliminarily defined as .

[0030] 303. Calculate the incident wave propagation direction unit vector and the received wave propagation direction unit vector based on the spatial position coordinates; In this embodiment, the unit vector of the incident wave propagation direction and the unit vector of the received wave propagation direction are calculated based on the spatial position coordinates of the transmitter and the receiver. The specific calculation method is as follows: First calculate the vector from the transmitter to the ship: ; Then the vector from the transmitter to the ship Normalize it and get the unit vector of the incident wave propagation direction ; Calculate the vector from the ship to the receiver: .

[0031] The vector from the ship to the receiver Normalization is performed to obtain the unit vector of the propagation direction of the received wave ; Through the above steps, the propagation direction unit vector of the incident wave and the received wave can be accurately determined, and necessary geometric information is provided for subsequent incident field and reflection field calculation.

[0032] Please refer to Figure 4 In the four embodiments of the ship bistatic RCS calculation method in the embodiment of the application, step 103 comprises: 401, obtaining an initial incident field amplitude and an incident field polarization direction unit vector; In this embodiment, the initial incident field amplitude and the incident field polarization direction unit vector need to be obtained first; the initial incident field amplitude can be calculated by the output power and the antenna gain of the radar transmitter; and the incident field polarization direction unit vector can be determined according to the polarization direction of the radar transmitter.

[0033] 402, 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; In this embodiment, the incident wave propagation direction unit vector , the initial incident field amplitude and the incident field polarization direction unit vector are used to calculate the incident field amplitude according to the incident field formula; the incident field formula is as follows: ; wherein, is a free space wave number, , is a wavelength; is an observation point position vector; is an imaginary unit, and its core definition is a mathematical symbol satisfying ; in electromagnetic and radar related engineering calculation, it is a standard practice to use complex numbers to represent electric field (or magnetic field), because the propagation process of electromagnetic wave contains amplitude and phase information, and the imaginary unit is a key mathematical tool for building complex numbers and describing the phase change rule with space position, which can accurately reflect the wave characteristics of electromagnetic wave; Through the above steps, the incident field amplitude can be accurately calculated, and necessary initial conditions are provided for subsequent RCS calculation.

[0034] Please refer to Figure 5 In the five embodiments of the ship bistatic RCS calculation method in the embodiment of the application, step 104 comprises: The ship-sea reflection path includes a first reflection path from the transmitter to the ship body 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 of the ship-sea path and a second reflection vector function of the ship-sea path.

[0035] 501、Based on the dielectric constants of the ship and the sea surface, the reflection coefficients of the first reflection path and the second reflection path are calculated respectively; In this embodiment, the reflection coefficients of the first reflection path and the second reflection path are calculated respectively based on the dielectric constants of the ship and the sea surface; The calculation formula of the reflection coefficient is as follows: ; In the formula, is the reflection coefficient, is the dielectric constant; For the first reflection path (from the transmitter to the ship body), the first reflection coefficient can be calculated according to the dielectric constant of the ship ; For the second reflection path (from the sea surface to the receiver), the second reflection coefficient can be calculated according to the dielectric constant of the sea surface .

[0036] 502、Based on the reflection coefficient of the first reflection path and the corresponding polarization direction, the reflection contribution calculation is performed to obtain the first reflection vector function of the ship-sea path; In this embodiment, based on the reflection coefficient of the first reflection path and the corresponding polarization direction, a reflection matrix is constructed, and the first reflection vector function of the ship-sea path is calculated in combination with geometric optics approximation; The elements of the first reflection matrix are defined as follows: ; ; Among them, is the matrix element of the first reflection matrix, and correspond to horizontal / vertical polarization respectively; is the unit matrix; is the unit vector of the polarization direction of the reflected wave; In the formula, is a 3x3 unit i matrix (the elements on the diagonal line in the matrix are 1, and the elements on the non-diagonal line are 0); is the reflected unit vector (three-dimensional vector), is the outer product of the vector (the form is a 3x3 matrix); in electromagnetic scattering calculation, is the classic "transverse wave projection operator", which removes the component parallel to , and only keeps the component perpendicular to to make the subsequent calculation results consistent with the transverse wave characteristics of the electromagnetic field; is a vector function describing the reflection direction of the first reflection field, which includes the unit vector of the wave vector of the incident wave , the unit vector of the polarization direction of the incident wave , and the unit vector of the surface normal , which affects the reflection field direction; Since the reflection path at this time is from the transmitter to the ship body, the unit vector of the surface normal is the unit vector of the surface normal of the ship body.

[0037] 503、Based on the reflection coefficient of the second reflection path and its corresponding polarization direction, the reflection contribution calculation is performed to obtain the second reflection vector function of the ship-sea path; In this embodiment, based on the reflection coefficient of the second reflection path and its corresponding polarization direction, a reflection matrix is constructed, and the second reflection vector function of the ship-sea path is calculated in combination with the geometric optics approximation; The elements of the second reflection matrix are defined as follows: ; ; Wherein, is the matrix element of the second reflection matrix, is the second reflection vector function, is a vector function describing the reflection direction of the first reflection field, which includes the unit vector of the wave vector of the incident wave , the unit vector of the polarization direction of the incident wave , and the unit vector of the surface normal , which affects the reflection field direction; is the unit vector of the wave vector of the incident wave to the sea surface, which is determined by the reflection wave vector of the first reflection path; Specifically, in the first reflection path, according to the mirror reflection condition, in combination with the unit vector of the incident wave propagation direction and the unit vector of the surface normal , the first reflection wave vector, i.e., the unit vector of the wave vector of the incident wave to the sea surface , can be calculated; Similarly, is the unit vector of the polarization direction of the incident wave to the sea surface, i.e., the unit vector of the incident wave polarization direction of the second reflection path, which is determined by the reflection wave polarization direction of the first reflection path; Specifically, in the first reflection path, according to the unit vector of the incident wave polarization direction , the unit vector of the reflection wave polarization direction, i.e., the unit vector of the polarization direction of the incident wave to the sea surface , can be calculated; At the same time, since the reflection path at this time is the transmitter to the ship body, the surface normal unit vector The sea surface normal unit vector is taken.

[0038] Please refer to Figure 6 The six embodiments of the ship two-station RCS calculation method in the embodiment of the application include the following steps 105: 601, calculating the total reflection vector function based on the ship-sea path reflection vector function; In this embodiment, the ship-sea path first reflection vector function and the ship-sea path second reflection vector function are extracted from the ship-sea path reflection vector function and the ship-sea path second reflection vector function are subjected to matrix operation, i.e., the total reflection vector function is obtained. ; The first reflection matrix and the second reflection matrix are subjected to non-commutative product operation, and the total reflection matrix is obtained; the non-commutative product reflects the order of the two reflection processes, i.e., the first reflection (from the transmitter to the ship body) occurs first, and then the second reflection (from the sea surface to the receiver) occurs.

[0039] 602, obtaining the sea surface reflection region and performing surface integration on the sea surface reflection region by using the Monte Carlo method to obtain the surface integration result; In this embodiment, the calculation steps of the surface integration result are as follows: First, a plurality of points are randomly sampled in the sea surface reflection integral region S; in order to ensure the accuracy and reliability of the integral result, at least 10 independent experimental samplings are performed; then, for each sampling point, the difference between the incident wave propagation direction unit vector and the receiving wave propagation direction unit vector is calculated, and the position vector of each sampling point is obtained; it should be noted that the shielding effect of the ship should be considered during the sampling process, and the sampling points in the shadow area should be excluded; finally, the contributions of all effective sampling points are integrated to obtain the sea surface reflection integral result; The expression of the sea surface reflection integral result is as follows: ; In the formula, ; is an imaginary unit, which is used to represent the phase change of the electromagnetic wave.

[0040] 603, calculating the ship-sea path reflection field amplitude based on the receiving wave propagation direction unit vector, the total reflection vector function, and the surface integration result; In this embodiment, the ship-sea path reflection field amplitude can be calculated based on a reflection field modeling formula: ; wherein, is the reflection field amplitude, is the Euclidean distance from the observation point to the reflection surface.

[0041] Referring to Figure 7 , the step 106 of the seven embodiments of the ship bistatic RCS calculation method in the embodiment of the application comprises: 701, substituting the incident field amplitude and the ship-sea path reflection field amplitude into a preset RCS calculation formula, and performing calculation based on a far field condition to obtain first station RCS data; In this embodiment, the incident field amplitude and the reflection field amplitude are substituted into a preset RCS calculation formula, and calculation is performed based on a far field condition, so that the first station RCS data can be obtained, and the specific process is as follows: ; wherein, RCS is the RCS data; the far field condition assumes that the reflection field propagates in the form of a spherical wave in the far field region, thereby simplifying the calculation.

[0042] The ship bistatic RCS calculation method in the embodiment of the application is described above, and the ship bistatic RCS calculation device in the embodiment of the application is described below. Referring to Figure 8 , one embodiment of the ship bistatic RCS calculation device in the embodiment of the application comprises: a background analysis module 801 configured to acquire 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 the sea surface physical parameters; a wave vector calculation module 802 configured to acquire the spatial position coordinates of a transmitter and a receiver and perform propagation vector calculation to obtain an incident wave propagation direction unit vector and a received wave propagation direction unit vector; an incident field calculation module 803 configured to calculate the incident field amplitude based on the incident wave propagation direction unit vector; a reflection analysis module 804 configured to acquire a ship-sea reflection path, perform reflection analysis based on the ship-sea reflection path, and perform reflection contribution calculation in combination with the dielectric constant of the ship and the sea surface to obtain a ship-sea path reflection vector function; a reflection field calculation module 805 configured to calculate the ship-sea path reflection field amplitude based on the received wave propagation direction unit vector and the ship-sea path reflection vector function; an RCS calculation module 806 configured 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 807 is configured to obtain the ship-sea reflection path, and return the ship-sea reflection path to the reflection analysis module 804 as a sea-ship reflection path, so as 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. In the embodiment, the background analysis module 801 calculates the dielectric constant of the ship and the sea surface based on the ship material parameters and the sea surface physical parameters; then, the wave vector calculation module 802 obtains the spatial position coordinates of the transmitter and the receiver and performs propagation vector calculation, and determines the unit vectors of the incident wave and the received wave propagation directions; then, the incident field calculation module 803 performs incident field modeling analysis based on the incident wave propagation direction unit vector, so as to obtain the incident field amplitude; the reflection analysis module 804 then performs reflection analysis based on the ship-sea reflection path, performs reflection contribution calculation in combination with the dielectric constant of the ship and the sea surface, and determines the double reflection contribution in the ship-sea reflection stage; the reflection field calculation module 805 then performs reflection field modeling in combination with the first reflection vector function, the second reflection vector and the received wave propagation direction unit vector, so as to obtain the reflection field amplitude; the RCS calculation module 806 calculates the first station RCS data based on the incident field amplitude and the reflection field amplitude; after the first station RCS calculation is completed, the path switching module 807 reverses the ship-sea reflection path to the sea-ship reflection path, and returns the reflection analysis module 804, so as to take the sea-ship reflection path as the analysis basis, recalculate the sea-ship reflection vector function, and then calculate the sea-ship path reflection field amplitude through the reflection field calculation module 805, and finally calculate the second station RCS data again through the RCS calculation module 806; the present application clearly distinguishes the double reflection contribution between the ship and the sea surface, accurately analyzes the sea-ship reflection path and the ship-sea reflection path, provides more accurate data support for RCS modeling, and provides more reliable technical support for ship detection in a complex sea scenario.

[0043] Figure 9is a structural schematic diagram of a ship bistatic RCS calculation device provided by an embodiment of the present application. The ship bistatic RCS calculation device 900 can have great differences due to different configurations or performances, and can include one or more central processing units (CPUs) 910 (for example, one or more processors) and a memory 920, one or more storage media 930 (for example, one or more mass storage devices) storing application programs 933 or data 932. The memory 920 and the storage media 930 can be temporary storage or persistent storage. The programs stored in the storage media 930 can include one or more modules (not shown in the figure), and each module can include a series of instruction operations in the ship bistatic RCS calculation device 900. Furthermore, the processor 910 can be configured to communicate with the storage media 930 and execute the series of instruction operations in the storage media 930 on the ship bistatic RCS calculation device 900 to implement the steps of the ship bistatic RCS calculation method provided by the above-mentioned method embodiments.

[0044] The ship bistatic RCS calculation device 900 can 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, and the like. Those skilled in the art can understand that the ship bistatic RCS calculation device 900 can also include other components, and the components shown in the figure are not exhaustive. Figure 9 The ship bistatic RCS calculation device structure shown does not constitute a limitation on the ship bistatic RCS calculation device, and can include more or fewer components than shown, or combine certain components, or different component arrangements.

[0045] The present application also provides a computer readable storage medium, which can be a non-volatile computer readable storage medium or a volatile computer readable storage medium. The computer readable storage medium stores instructions, and when the instructions are run on a computer, the computer executes the steps of the ship bistatic RCS calculation method.

[0046] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described system or device, unit can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0047] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0048] Finally, it should be noted that: the above only for the preferred examples of the present application, and not for limiting the present application, although the present application is described in detail with reference to the foregoing examples, for those skilled in the art, it still can be modified to the technical solutions recorded in the foregoing embodiments, or equivalent replacement of some technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for calculating dual-station RCS of a ship, characterized in that: include: Obtaining the ship's material parameters and the sea's physical parameters, and calculating the dielectric constant between the ship and the sea based on the ship's material parameters and the sea's physical parameters; Obtain the spatial coordinates of the transmitter and receiver and perform propagation vector calculations to obtain the unit vectors of the incident wave propagation direction and the received wave propagation direction; The incident field amplitude is calculated based on the unit vector of the incident wave propagation direction; Obtain the ship-sea reflection path, perform reflection analysis based on the ship-sea reflection path, and calculate the reflection contribution based on the dielectric constants of the ship and the sea surface to obtain the ship-sea path reflection vector function; The amplitude of the ship-sea path reflection field is calculated based on the unit vector of the received wave propagation direction and the ship-sea path reflection vector function; The RCS data of the first station is calculated based on the amplitude of the incident field and the amplitude of the reflected field of the ship-sea path; Obtain the ship reflection path and use it 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 ship path reflection field, and calculate the RCS data of the second station based on the incident field amplitude and the ship path reflection field amplitude.

2. The ship dual-station RCS calculation method according to claim 1, characterized in that: The dielectric constants of the ship and the sea surface calculated based on the ship material parameters and the sea surface physical parameters include: Obtain ship material parameters and sea surface physical parameters; The material parameters of the ship and the physical parameters of the sea surface are input into the preset sea surface characteristic calculation model to calculate the dielectric constant between the ship and the sea surface.

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

4. The method for calculating the ship's dual-station RCS according to claim 1, wherein: The calculation of the incident field amplitude based on the incident wave unit vector includes: Obtain the initial incident field amplitude and the incident field polarization direction unit vector; 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 dual-station RCS calculation method according to claim 1, characterized in that: The obtaining of the ship-sea reflection path, performing reflection analysis based on the ship-sea reflection path, and calculating the reflection contribution in combination 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; Calculating the reflection coefficients of the first reflection path and the second reflection path based on the dielectric constants of the ship and the sea surface; Calculating 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; 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.

6. The ship dual-station RCS calculation method according to claim 1, characterized in that: The calculation of the ship-sea path reflection field amplitude based on the received wave propagation direction unit vector 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; Obtain the sea surface reflection area, and use the Monte Carlo method to perform surface integration on the sea surface reflection area to obtain a 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 integration result.

7. The method for calculating ship dual-station RCS according to claim 1, characterized in that: The calculation of the first station RCS data based on the incident field amplitude and the ship-sea path reflection field amplitude includes: Substitute the incident field amplitude and the ship-sea path reflection field amplitude into the preset RCS calculation formula, and calculate based on the far-field conditions to obtain the RCS data of the first station.

8. A ship dual-station RCS calculation device, characterized in that: include: Background analysis module, used to obtain ship material parameters and sea surface physical parameters, and calculate the dielectric constant between 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 the 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; An 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 obtain the ship-sea reflection path, perform reflection analysis based on the ship-sea reflection path, and calculate the reflection contribution based on the dielectric constant of the ship and the sea surface to obtain the ship-sea path reflection vector function; A reflection field calculation module is used to calculate 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; RCS calculation module, used to calculate the RCS data of the first station based on the amplitude of the incident field and the amplitude of the reflected field of the ship-sea path; The path switching module is used to obtain the ship reflection path and use the ship reflection path as the ship-sea reflection path, return to the reflection analysis module to calculate the amplitude of the ship path reflection field, and calculate the second station RCS data based on the incident field amplitude and the ship path reflection field amplitude.

9. A ship dual-station RCS calculation device, characterized in that: The ship dual-station RCS calculation device includes: a memory and at least one processor, wherein the memory stores instructions; At least one of the processors calls the instructions in the memory to enable the ship dual-station RCS calculation device to perform each step of the ship dual-station RCS calculation method according to any one of claims 1 to 7.

10. A computer-readable storage medium having instructions stored thereon, characterized in that: When the instructions are executed by a processor, the steps of the ship dual-station RCS calculation method according to any one of claims 1 to 7 are implemented.

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