A method and system for calculating sea surface electromagnetic scattering coefficients under two-dimensional flow field

Abstract

The application provides a method and system for calculating the electromagnetic scattering coefficient of a sea surface under the action of a two-dimensional flow field, comprising the following steps: step 1, setting a sea surface area to be observed, setting flow field and wind field data, and setting radar parameters; step 2, setting relevant parameters in a wave-current interaction model, and establishing a wave action spectrum conservation equation according to the wave-current interaction model; step 3, solving the wave action spectrum conservation equation by using a ray tracing method to obtain a new wave action spectrum of a wave train after the wave train is modulated by the flow field; step 4, converting the new wave action spectrum obtained in step 3 into a wave height spectrum, and calculating sea level related information including the root mean square height and the local incidence angle of each point by using the wave height spectrum; and step 5, inputting the calculated sea surface information and the set radar parameters into an IEM electromagnetic scattering model to calculate the modulated backscattering coefficient. The flow field modulation model based on the IEM model can effectively calculate the electromagnetic scattering of the sea surface under the modulation of the two-dimensional flow field.

Description

Technical Field

[0001] This invention belongs to the field of marine microwave remote sensing technology, and particularly relates to a method and system for calculating the electromagnetic scattering coefficient of the sea surface under the action of a two-dimensional flow field. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Ocean currents are large-scale forms of seawater movement, reflecting the transport of seawater at different scales. Between different sea areas, ocean currents carry sediment and other materials, causing changes in coastal zones and the deposition of ocean floor sediments, thus affecting the construction of marine engineering projects and changes in ocean shipping routes. Furthermore, ocean transportation, marine search and rescue, marine fisheries production, and marine environmental monitoring are all closely related to ocean currents.

[0004] Therefore, the study of sea surface flow fields has become a hot topic in physical oceanography. Currently, spaceborne SAR inversion methods for sea surface flow are limited to studying the radial surface velocity of the radar. Research on two-dimensional flow fields is still in the exploratory stage, with the use of compound-eye SAR system configurations employing one-to-many and multiple-to-many signals being a hot topic for two-dimensional flow field inversion. Based on the fundamental theory of ocean current microwave remote sensing, SAR observation of the ocean mainly utilizes the backscattering of the sea surface formed by the interaction between microwaves and microscale waves on the sea surface, as well as the modulation signals of various ocean phenomena and processes that affect sea surface backscattering. Therefore, studying the changes in the sea surface radar scattering coefficient under two-dimensional flow field modulation is of great significance for exploring the detection mechanism and imaging mechanism of new SAR systems. Existing methods for calculating sea surface electromagnetic scattering under ocean currents are mainly based on one-dimensional sea surfaces and use relatively complex electromagnetic scattering models. Furthermore, the calculation of ocean current modulation under two-dimensional ocean currents is more complex and computationally intensive, requiring further consideration of the influence of ocean current direction. Therefore, research on the calculation of sea surface electromagnetic scattering coefficients under two-dimensional ocean currents is currently lacking. Summary of the Invention

[0005] To overcome the shortcomings of the existing technologies, this invention proposes a computational model based on the IEM electromagnetic scattering model for calculating the electromagnetic scattering coefficient of the sea surface under the influence of two-dimensional ocean currents. This method uses wind and current field information of the sea surface as model inputs, and employs an electromagnetic scattering calculation method based on the IEM model and a current field modulation calculation method based on the wave-current interaction model as modeling tools to effectively calculate the electromagnetic scattering of the sea surface under current field modulation.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0007] The first aspect of this invention provides a method for calculating the electromagnetic scattering coefficient of the sea surface under the action of a two-dimensional flow field, comprising:

[0008] Step 1: Set the sea surface area to be observed, and set the flow field, wind field data and radar parameters;

[0009] Step 2: Set the relevant parameters in the wave-current interaction model, including setting the source function and the sea surface wave spectrum, and establish the wave action spectrum conservation equation based on the wave-current interaction model;

[0010] Step 3: Solve the wave action spectrum conservation equation using the ray tracing method to obtain the new wave action spectrum of each point wave train after flow field modulation;

[0011] Step 4: Convert the new wave action spectrum obtained in Step 3 into a wave height spectrum, and use the wave height spectrum of the equilibrium state at each point to calculate sea level related information, including the root mean square height and local incident angle at each point.

[0012] Step 5: Input the calculated sea surface information and the set radar parameters into the IEM electromagnetic scattering model, and calculate the modulated backscattering coefficient.

[0013] Furthermore, the setting of the sea surface area to be observed includes: setting the sea surface size to 100m×100m and the sea surface resolution to 5m×5m;

[0014] The set flow field and wind field data include: the ocean current direction is the positive x-axis, the angle between the flow direction and the wind direction is in the same direction, and the flow velocity and wind speed in the x and y directions are set for each sampling point;

[0015] The radar parameters are set as follows: the radar frequency is set to 5.6 GHz, the polarization mode is HH polarization, the radar incident direction is the positive x-axis, and the radar wave incident angle is 30°, 50°, or 70°.

[0016] Furthermore, the original function is a finite quadratic source function, and the wave action spectrum of the initial state adopts the Romeiser spectrum.

[0017] Furthermore, the wave action spectrum conservation equation is:

[0018]

[0019] Where N is the wave action spectrum, S is the source function, k and l are the spatial wave number and position of the wave vector, and k = (k x ,k y ), l=(x,y), the changes of k and l with respect to time t are described by the ray equations respectively.

[0020] Furthermore, the equation for the ray that l changes with time is:

[0021]

[0022] The equation for the ray that k varies with time is:

[0023]

[0024] Among them, c g (k) represents the group velocity of the wave packet, and U(l) = (u,v) is the input two-dimensional sea surface current. This flow field causes the natural angular frequency ω0 of the wave to undergo Doppler shift, resulting in the apparent frequency ω, ω = ω0 + kU(l), where u represents the flow velocity in the x-direction and v represents the flow velocity in the y-direction.

[0025] Furthermore, in the calculation of sea level-related information, the wavenumber integration range is selected as (k0×0.4, k0×10);

[0026] Furthermore, the expression for the IEM electromagnetic scattering model under backscattering is:

[0027]

[0028] Where k i Let θ be the radar wave number and θ be the radar wave incident angle. w represents the quantity associated with the tangent plane approximation field and the compensation field. (n) (2k i sinθ,0) represents the nth-order roughness spectrum, obtained by performing an nth-order Fourier transform on the sea surface autocorrelation function.

[0029]

[0030] Where f αβ F represents the Kirchhoff field coefficients. αβ α represents the compensation field coefficient, and β represents horizontal or vertical polarization. x k y k z k sx k sy k sz Is with k i Relevant geometric parameters. σ is the root mean square height of the sea surface, which can be calculated from the wave spectrum.

[0031] A second aspect of the present invention provides a system for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field, comprising:

[0032] The parameter setting module is configured to: set the sea surface area to be observed, set the flow field, wind field data and radar parameters;

[0033] The wave action spectrum conservation equation establishment module is configured to: set relevant parameters in the wave-current interaction model, including setting the source function and the sea surface wave spectrum, and establish the wave action spectrum conservation equation based on the wave-current interaction model;

[0034] The wave action spectrum conservation equation solution module is configured to: use the ray tracing method to solve the wave action spectrum conservation equation to obtain the new wave action spectrum of each point wave train after flow field modulation;

[0035] The sea level related information calculation module is configured to: convert the calculated new wave action spectrum into a wave height spectrum, and use the calculated wave height spectrum of the equilibrium state at each point to calculate sea level related information, including the root mean square height and local incident angle at each point.

[0036] The backscattering coefficient calculation module is configured to input the calculated sea surface information and the set radar parameters into the IEM electromagnetic scattering model to calculate the modulated backscattering coefficient.

[0037] A third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps in the method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field.

[0038] A fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that the processor executes the program to implement the steps in the method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field.

[0039] The above one or more technical solutions have the following beneficial effects:

[0040] 1. This invention utilizes the advantages of IEM model in terms of accuracy, wide applicability, and suitability for flow field research to propose a flow field modulation model based on IEM model, which can effectively calculate the electromagnetic scattering of the sea surface under two-dimensional flow field modulation.

[0041] 2. By using the ray tracing method to solve the wave-current interaction model, the surface wave spectrum under ocean current modulation can be calculated more quickly and accurately.

[0042] 3. It can calculate the backscattering coefficient of the sea surface under two-dimensional flow field modulation, which is beneficial to the construction and research of new SAR systems and solves the problem of lack of research on the calculation of the electromagnetic scattering coefficient of the sea surface under two-dimensional ocean current in the existing technology.

[0043] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0044] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0045] Figure 1 This is a flowchart of a method according to Embodiment 1 of the present invention.

[0046] Figure 2 This is a schematic diagram showing the variation of the sea surface backscattering coefficient with distance under a one-dimensional varying flow field input.

[0047] Figure 3 This is a graph showing the relationship between the backscattering coefficient of the sea surface and the current velocity when different current velocities act on the same sea surface.

[0048] Figure 4 This is a schematic diagram comparing the backscattering coefficient calculated by this method with that extracted from satellite images under a two-dimensional flow field; (a) represents the verification point selected in the Gulf of Mexico region (represented by a pentagram), with the background being the flow velocity in this region obtained from HYCOM model data; (b) shows the comparison between the backscattering value corresponding to the verification point in the Sentinel-1a satellite image and the backscattering value calculated by this invention. Detailed Implementation

[0049] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0050] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0051] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0052] Example 1

[0053] This embodiment discloses a method for calculating the electromagnetic scattering coefficient of the sea surface under the action of a two-dimensional flow field;

[0054] like Figure 1 As shown, a method for calculating the electromagnetic scattering coefficient of the sea surface under the action of a two-dimensional flow field includes:

[0055] Step 1: Set the sea surface area to be observed, and set the flow field, wind field data and radar parameters;

[0056] The sea surface area to be observed is defined as follows: the sea surface size is set to 100m×100m, and the sea surface resolution is 5m×5m.

[0057] The set flow field and wind field data include: the ocean current direction is the positive x-axis, the angle between the flow direction and the wind direction is in the same direction, and the flow velocity and wind speed in the x and y directions are set for each sampling point; the wind field and flow field model settings should conform to the principle of the same sampling matrix, that is, the size of the wind field and flow field and the sampling interval should be consistent, so as to facilitate the subsequent wave-current modulation model solution;

[0058] The radar parameters are set as follows: the radar frequency is set to 5.6 GHz, the polarization mode is HH polarization, the radar incident direction is the positive x-axis, and the radar wave incident angle is 30°, 50°, or 70°.

[0059] Step 2: Set the relevant parameters in the wave-current interaction model, including setting the source function and the sea surface wave spectrum, and establish the wave action spectrum conservation equation based on the wave-current interaction model;

[0060] Specifically, common source functions include first-order linear source functions and finite quadratic source functions. In this invention, finite quadratic source functions are selected:

[0061]

[0062] Where μ is the relaxation rate and N0 is the wave action in the initial state.

[0063] The initial wave action spectrum uses the Romeiser spectrum, which is a full wavenumber spectrum and can obtain wave modulation conditions over a wider wavenumber range. It has good applicability in the L-Ku band. This spectrum is represented as follows:

[0064]

[0065]

[0066]

[0067]

[0068] Where u n =1m / s, k n =1 rad / m, c1 = 400 rad / s P(k) and W s (k) represents the coefficient related to wave number k, φ represents the wind direction angle, k1 = 183 rad / m, k2 = 3333 rad / m, k3 = 33 rad / m, k4 = 140 rad / m, k5 = 220 rad / m.

[0069] Under the influence of the flow field, microscale waves, represented by Bragg waves on the sea surface, are affected by the wave-current interaction. The energy of different wave trains changes, but their action spectrum is conserved. The wave-current interaction can be described by the wave action conservation equation:

[0070]

[0071] Where N is the action spectrum of the wave, S is the source function, k and l are the spatial wave number and position of the wave vector, and k = (k x ,k y ), l=(x,y),

[0072] The changes of k and l with respect to time can be described by two ray equations:

[0073]

[0074]

[0075] Where c g (k) represents the group velocity of the wave packet, and U(l) = (u,v) is the input two-dimensional sea surface current. This current field causes a Doppler shift in the natural angular frequency ω0 of the wave, resulting in the apparent frequency ω, ω = ω0 + kU(l). Under the wireless depth approximation, u represents the flow velocity in the x-direction, and v represents the flow velocity in the y-direction.

[0076] Step 3: Solve the wave action spectrum conservation equation using the ray tracing method to obtain the new wave action spectrum of each point wave train after flow field modulation;

[0077] The purpose of the differential equation in equation (3) is to calculate the equilibrium action spectrum after a certain period of time. To ensure the reliability of the calculation, this method uses the ray tracing method for solution. Its advantage is that it can ensure the accuracy of the equation calculation and can change the source function without making complex modifications. The essence of this method is that nonlinear action affects the wave action spectrum. The changing flow field will cause the wave action spectrum to redistribute and recover equilibrium within a certain relaxation time. By tracing back along time using the ray equation, after a sufficiently long time or after reaching the boundary, positive integration is performed to ensure that the wave action reaches equilibrium. Finally, the new wave action spectrum of each point wave train after flow field modulation is obtained.

[0078] Step 4: Convert the new wave action spectrum obtained in Step 3 into a wave height spectrum, and use the wave height spectrum of the equilibrium state at each point to calculate sea level related information, including the root mean square height and local incident angle at each point.

[0079] The action spectrum can be converted into the energy spectrum E and the wave height spectrum W. The relationship between the three is as follows:

[0080]

[0081] Where ρ = 1025 kg / m 3 .

[0082] After solving step 4, the modulation spectrum at each sampling point will be obtained. σ is the root mean square height of the sea surface, which can be calculated from the wave spectrum. This is a key input parameter for the calculation of the sea surface electromagnetic scattering model.

[0083]

[0084] Since only a portion of the wave wavelengths interact with electromagnetic waves in sea surface scattering calculations, the integration range must be considered when calculating the required geometric parameters. Here, the wave number integration range is selected as (k0×0.4, k0×10), and the root mean square height of the sea surface is shown below:

[0085]

[0086] Where φ represents the wind direction angle.

[0087] The local angle of incidence at the sea surface is calculated as follows:

[0088]

[0089] Where θ i Represents the angle of incidence, φ i Represents the incident azimuth angle, z x and z y This represents the slope of the sea surface in the x and y directions.

[0090] Step 5: Input the calculated sea surface information and the set radar parameters into the IEM electromagnetic scattering model, and calculate the modulated backscattering coefficient.

[0091] The IEM electromagnetic scattering model is a rough surface scattering field model derived from the electromagnetic wave propagation equation. It introduces a compensation field based on the Kirchhoff model. The advantages of this model are its wide applicability to a wide range of roughness and the fact that it does not require consideration of scale division, thus it is widely used in the study of electromagnetic scattering in surface and marine environments. Experiments have shown that this model can effectively calculate the modulation of the sea surface backscattering coefficient by internal waves. Therefore, this invention uses the IEM electromagnetic scattering model to study the influence of the sea surface current field on the sea surface electromagnetic backscattering coefficient.

[0092] The expression for this model under backscattering is:

[0093]

[0094] Where k i Let θ be the radar wave number and θ be the radar wave incident angle. w represents the quantity associated with the tangent plane approximation field and the compensation field. (n) (2k i sinθ,0) represents the nth-order roughness spectrum, which can be obtained by performing an nth-order Fourier transform on the sea surface autocorrelation function. The sea surface wave spectrum under equilibrium conditions is represented by the Romiser spectrum.

[0095] like Figure 2 As shown, when a 1000-meter-long variable one-dimensional flow field is input, the sea surface backscattering coefficient is modulated by the flow field. The gradient change of the flow field causes the sea surface backscattering coefficient to exhibit an opposite gradient change. The backscattering coefficient is different at different flow velocities, which also explains why internal waves appear as bright and dark stripes in satellite images, proving the rationality of the present invention.

[0096] The modulation spectrum and root mean square height information calculated at each point are input into the IEM electromagnetic scattering model. Since the calculation results show convergence characteristics as the spectral order n increases, n is set to 15. Figure 3 The variation of the sea surface backscattering coefficient under different incident angles and different flow velocities is shown, where the flow velocity represents the average flow velocity within a defined sea surface area.

[0097] like Figure 4 As shown in (a), the backscattering values ​​in the Gulf of Mexico using Sentinel-1a satellite data are compared with the backscattering values ​​calculated using the method of the invention. Verification points with a certain velocity gradient are selected (indicated by pentagrams). The input flow field and wind field data are HYCOM flow field data and ERA5 wind field data from the same time and space. Figure 4 (b) shows a comparison between the backscattering values ​​corresponding to the verification points in the Sentinel-1a satellite image and the backscattering values ​​calculated by this invention. It can be seen that the results are quite consistent, further verifying the reliability of this method.

[0098] Example 2

[0099] This embodiment discloses a system for calculating the electromagnetic scattering coefficient of the sea surface under the action of a two-dimensional flow field, including:

[0100] The parameter setting module is configured to: set the sea surface area to be observed, set the flow field, wind field data and radar parameters;

[0101] The wave action spectrum conservation equation establishment module is configured to: set relevant parameters in the wave-current interaction model, including setting the source function and the sea surface wave spectrum, and establish the wave action spectrum conservation equation based on the wave-current interaction model;

[0102] The wave action spectrum conservation equation solution module is configured to: use the ray tracing method to solve the wave action spectrum conservation equation to obtain the new wave action spectrum of each point wave train after flow field modulation;

[0103] The sea level related information calculation module is configured to: convert the calculated new wave action spectrum into a wave height spectrum, and use the calculated wave height spectrum of the equilibrium state at each point to calculate sea level related information, including the root mean square height and local incident angle at each point.

[0104] The backscattering coefficient calculation module is configured to input the calculated sea surface information and the set radar parameters into the IEM electromagnetic scattering model to calculate the modulated backscattering coefficient.

[0105] Example 3

[0106] The purpose of this embodiment is to provide a computer-readable storage medium.

[0107] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in Embodiment 1 of this disclosure.

[0108] Example 4

[0109] The purpose of this embodiment is to provide an electronic device.

[0110] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in the method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in Embodiment 1 of this disclosure.

[0111] The steps and methods involved in the apparatuses of Embodiments 2, 3, and 4 above correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood as including any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and enabling the processor to perform any of the methods in this invention.

[0112] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0113] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field, characterized in that, include: Step 1: Set the sea surface area to be observed, and set the flow field, wind field data and radar parameters; Step 2: Set the relevant parameters in the wave-current interaction model, including setting the source function and the sea surface wave spectrum; Step 3: Establish the wave action spectrum conservation equation based on the wave-current interaction model, and solve the wave action spectrum conservation equation using the ray tracing method to obtain the new wave action spectrum of each point wave train after flow field modulation. Step 4: Convert the new wave action spectrum obtained in Step 3 into a wave height spectrum, and use the wave height spectrum of the equilibrium state at each point to calculate sea level related information, including the root mean square height and local incident angle at each point. Step 5: Input the calculated sea surface information and the set radar parameters into the IEM electromagnetic scattering model, and calculate the modulated backscattering coefficient.

2. The method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in claim 1, characterized in that, The set sea surface area to be observed includes: setting the sea surface size to 100m×100m and the sea surface resolution to 5m×5m; The set flow field and wind field data include: the ocean current direction is the positive x-axis, the angle between the flow direction and the wind direction is in the same direction, and the flow velocity and wind speed in the x and y directions are set for each sampling point; The radar parameters are set as follows: the radar frequency is set to 5.6 GHz, the polarization mode is HH polarization, the radar incident direction is the positive x-axis, and the radar wave incident angle is 30°, 50°, or 70°.

3. The method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in claim 1, characterized in that, The original function is a finite quadratic source function, and the wave action spectrum of the initial state adopts the Romeiser spectrum.

4. The method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in claim 1, characterized in that, The wave action spectrum conservation equation is: Where N is the wave action spectrum, S is the source function, k and l are the spatial wave number and position of the wave vector, and k = (k x ,k y ), l=(x,y), the changes of k and l with respect to time t are described by the ray equations respectively.

5. The method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in claim 4, characterized in that, The equation for the ray that l changes with time is: The equation for the ray that k varies with time is: Among them, c g (k) represents the group velocity of the wave packet, and U(l) = (u,v) is the input two-dimensional sea surface current. This flow field causes the natural angular frequency ω0 of the wave to undergo Doppler shift, resulting in the apparent frequency ω, ω = ω0 + kU(l), where u represents the flow velocity in the x-direction and v represents the flow velocity in the y-direction.

6. The method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in claim 1, characterized in that, In the calculation of sea level related information, the wave number integration range was selected as (k0×0.4, k0×10).

7. The method for calculating the electromagnetic scattering coefficient of the sea surface under a two-dimensional flow field as described in claim 1, characterized in that, The expression for the IEM electromagnetic scattering model under backscattering is: Where k i Let θ be the radar wave number and θ be the radar wave incident angle. w represents the quantity associated with the tangent plane approximation field and the compensation field. (n) (2k i sinθ,0) represents the nth-order roughness spectrum, obtained by performing an nth-order Fourier transform on the sea surface autocorrelation function. Where f αβ F represents the Kirchhoff field coefficients. αβ The coefficients represent the compensation field coefficients, α and β represent horizontal or vertical polarization, and k represents the field coefficients. x k y k z k sx k sy k sz Is with k i The relevant geometric parameter, σ, is the root mean square height of the sea surface, which can be calculated from the wave spectrum.

8. A system for calculating the electromagnetic scattering coefficient of the sea surface under two-dimensional flow field, characterized in that: include: The parameter setting module is configured to: set the sea surface area to be observed, set the flow field, wind field data and radar parameters; The wave action spectrum conservation equation establishment module is configured to: set relevant parameters in the wave-current interaction model, including setting the source function and the sea surface wave spectrum, and establish the wave action spectrum conservation equation based on the wave-current interaction model; The wave action spectrum conservation equation solution module is configured to: use the ray tracing method to solve the wave action spectrum conservation equation to obtain the new wave action spectrum of each point wave train after flow field modulation; The sea level related information calculation module is configured to: convert the calculated new wave action spectrum into a wave height spectrum, and use the calculated wave height spectrum of the equilibrium state at each point to calculate sea level related information, including the root mean square height and local incident angle at each point. The backscattering coefficient calculation module is configured to input the calculated sea surface information and the set radar parameters into the IEM electromagnetic scattering model to calculate the modulated backscattering coefficient.

9. A computer-readable storage medium having a program stored thereon, characterized in that, When executed by the processor, the program implements the steps in the method for calculating the electromagnetic scattering coefficient of the sea surface under the action of a two-dimensional flow field as described in any one of claims 1-7.

10. An electronic device, comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the method for calculating the electromagnetic scattering coefficient of the sea surface under the action of a two-dimensional flow field as described in any one of claims 1-7.

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