CN108388732A - Plunder extra large Target multipath scattering properties emulated computation method and system - Google Patents

Abstract

The embodiment of the present invention proposes a simulation calculation method and system for the multipath scattering characteristics of sea-skimming targets, which relates to the technical field of radar target characteristics. The method includes: binning the sea surface samples; local sea surface bin scattering rate of the sea surface sample; the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target body is calculated by the physical optics method and the equivalent electromagnetic current method; the target and the sea surface itself are combined by the mirror image method Scattering properties, which calculate the multipath-coupled scattering of the target-sea surface. The method and system for simulating and calculating the multipath scattering characteristics of sea-skimming targets provided by the embodiments of the present invention can reflect the local coupled scattering characteristics of the sea surface and targets in the real radar view, thereby accurately simulating the multipath scattering characteristics of sea-skimming targets, and can be used for skimming Remote sensing detection of sea targets.

Description

Simulation calculation method and system for multipath scattering characteristics of sea-skimming targets

technical field

The invention relates to the technical field of radar target characteristics, in particular to a simulation calculation method and system for multipath scattering characteristics of sea-skimming targets.

Background technique

Our country has a long coastline, and the sea-skimming and low-flying low-flying penetration target is one of the main threats to our air defense system. At present, foreign advanced cruise missiles and anti-ship missiles have been able to penetrate the sea at a height as low as 5m, and can carry out precise strikes on China's large surface ships, coastal defense facilities, nuclear bases, arsenals, command centers and other core military targets. Homeland air defense poses a great threat. The radar echo is easily interfered by multipath scattering when the radar system is used to detect and track sea-skimming targets. The multipath scattering comes from the electromagnetic coupling scattering between the target and the sea surface. Please refer to Figure 1. Figure 1 shows the schematic diagram of the multipath scattering of the ultra-low-altitude target of the radar seeker. The multipath scattering will enter the radar together with the target echo. The system forms serious interference, leading to fluctuations in radar echoes, tracking out-of-tolerance, false alarms and other abnormal phenomena. Multipath interference has strong target-like characteristics. Compared with other radar interferences, it is difficult to separate and suppress radar echoes in the space, time, and frequency domains. Studying the multipath scattering characteristics of sea-skimming low-flying targets and its influence on radar and guidance systems is of great significance to the evaluation, improvement and promotion of ultra-low-altitude performance of air defense system weapons and equipment. However, due to the complexity of the marine environment, the cost of using experimental methods to study multipath scattering characteristics is high, and it is difficult to obtain measured data in many real and complex situations, which has certain limitations. In contrast, using theoretical models for digital simulation has significant advantages such as low cost, high flexibility, and wide application range.

Contents of the invention

The object of the present invention is to provide a sea-skimming target multipath scattering characteristic simulation calculation method and system, which can reflect the local coupling scattering characteristics between the sea surface and the target.

In order to achieve the above object, the technical solution adopted in the embodiment of the present invention is as follows:

An embodiment of the present invention provides a method for simulating and calculating the multipath scattering characteristics of a sea-skimming target, the method comprising:

Perform binning processing on sea surface samples;

Using a binning double-scale algorithm to calculate the local sea surface bin scattering rate of the sea surface sample after the binning process;

According to the physical optics algorithm and the equivalent electromagnetic current algorithm, the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target is obtained;

According to the scattering rate of the local sea surface bin, the image radar electromagnetic wave generated by the radar electromagnetic wave on the local sea surface bin and the image induced electromagnetic wave generated by the image radar electromagnetic wave on the surface and edge structure of the target flow is corrected;

According to the induced electromagnetic current generated by the radar electromagnetic wave and the corrected image induced electromagnetic current generated by the mirrored radar electromagnetic wave, the scattering field generated by the radar electromagnetic wave on the surface and edge structure of the target is determined.

Further, the step of binning the sea surface sample includes:

According to the stochastic rough surface theory, the Monte Carlo method is used to process the Efouhaily sea spectrum model to obtain sea surface samples;

Perform binning processing on the large-scale contour surface of the sea surface sample.

Further, according to the dual-scale theory, the scattering field of the local sea surface bin of the sea surface sample includes a coherent component and an incoherent component, and the scattering rate of the local sea surface bin is expressed as:

in, The scattering coefficient representing the coherent component of the scattering field of the local sea surface bin is obtained by using the Kirhoff approximation algorithm, The scattering coefficient representing the incoherent component of the scattering field of the local sea surface bin is obtained by a perturbation method.

Further, after processing the coherent component using the Kirhoff approximation algorithm, the scattering rate of the local sea surface bin is expressed as:

Among them, q represents the scattering vector, Γ _pq represents the coherent polarization scattering coefficient, and prob(·) represents the probability density function of the sea surface large-scale bin distribution.

Further, after the incoherent component is processed by the perturbation method, the scattering rate of the local sea surface bin is expressed as:

Among them, F _pq represents the incoherent polarization scattering coefficient, and W _ζ (q _l ) represents the spectral distribution of the microstructure on the local sea surface bin.

Further, the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target body is expressed as:

After the surface of the target body is subdivided by plane triangular bins, the scattering field generated by the local sea surface bins in the far region is expressed as:

Wherein, ΔS characterizes the area of the plane triangle angle element, I characterizes the phase part, and

Further, the expressions of the equivalent current J _e and the equivalent magnetic current J _m generated by the radar electromagnetic wave at the edge structure of the target are respectively:

The expression of the diffraction field produced by the edge structure of the target body in the far zone is:

in, Characterize the tangent vector of the edge structure of the target body, E _i and H _i respectively represent the incident electric field and the incident magnetic field generated by the radar electromagnetic wave at the edge structure of the target body, and β _i and β _s respectively represent the The angle between the incident direction of the radar electromagnetic wave and the edge structure of the target body and the angle between the scattering direction of the radar electromagnetic wave and the edge structure of the target body, D _e and D _m are Diffraction coefficient.

Further, according to the induced electromagnetic current generated by the radar electromagnetic wave and the mirror image induced electromagnetic current generated by the mirrored radar electromagnetic wave, the scattering of the radar electromagnetic wave on the surface and edge structure of the target is determined. field steps, including:

The result of vector summation of the induced electromagnetic current generated by the radar electromagnetic wave and the mirror induced electromagnetic current generated by the mirrored radar electromagnetic wave is used as the scattering of the radar electromagnetic wave on the surface and edge structure of the target field.

An embodiment of the present invention also provides a sea-skimming target multipath scattering characteristic simulation calculation system, the system includes:

The sea surface sample processing module is used for binning the sea surface samples;

A scatter rate calculation module, configured to calculate the local sea surface bin scatter rate of the sea surface sample after binning processing by using a binning double-scale algorithm;

The induced electromagnetic current calculation module is used to obtain the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target according to the physical optics algorithm and the equivalent electromagnetic current algorithm;

A correction module, configured to analyze the image radar electromagnetic wave generated by the radar electromagnetic wave on the local sea surface bin and the image radar electromagnetic wave on the surface and edge structure of the target according to the scattering rate of the local sea surface bin The generated mirror induced electromagnetic current is corrected;

The scattering field simulation module is used to determine the radar electromagnetic wave on the surface and edge of the target according to the induced electromagnetic current generated by the radar electromagnetic wave and the corrected image induced electromagnetic current generated by the mirror image radar electromagnetic wave Scattering fields generated by structures.

Further, the sea surface sample processing module includes:

The sea surface sample processing unit is used to process the Efouhaily sea spectrum model with the Monte Carlo method according to the stochastic rough surface theory to obtain sea surface samples;

The binning unit is used to bin the large-scale contour surface of the sea surface sample.

Compared with the prior art, the embodiments of the present invention provide a method and system for simulating and calculating the multipath scattering characteristics of sea-skimming targets. By adopting random rough surface theory combined with sea spectrum function and Monte Carlo method to simulate the Real ocean contour samples, and large-scale sea surface contours are processed into bins at the same time. The scattering of the sea surface bins is calculated by the revised binning dual-scale model, and the coupling scattering between the local bins and the target is taken into account in combination with the mirror image method, and then coherent Superposition can accurately and efficiently simulate the multipath scattering characteristics of large-scale targets above the sea surface under complex sea conditions. Compared with traditional calculation models and methods, it can reflect the local coupling scattering characteristics of the sea surface and targets, thus enabling more accurate and efficient calculation of sea-skimming The multipath scattering of the target, and it is easier to apply to observe the characteristics of multipath scattering on the one-dimensional image and SAR image of the sea surface target.

In order to make the above-mentioned objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 shows the schematic diagram of radar seeker ultra-low-altitude target multipath scattering;

Fig. 2 shows the schematic diagram of the mirror image generated by the ultra-low-altitude point target under radar illumination;

Fig. 3 shows a schematic flow chart of a method for simulating and calculating the multipath scattering characteristics of a sea-skimming target provided by an embodiment of the present invention;

FIG. 4 shows a schematic diagram of a double-scale model of the sea surface and a mirror image of a sea-skimming target provided by an embodiment of the present invention;

Fig. 5 shows the schematic diagram of the surface element model of the sea surface when the wind speed is 3m/s at a height of 10m on the sea surface;

Fig. 6 shows the schematic diagram of the image scattering coefficient of the element under the VV polarization condition of the sea surface element;

FIG. 7 shows a schematic diagram of a bin mirroring process;

Fig. 8 is a kind of schematic flowchart of the substep of step S100 in Fig. 3;

Figure 9 shows the calculation results of HH polarization in the multipath scattering calculation;

Figure 10 shows the calculation results of VV polarization in the multipath scattering calculation;

Fig. 11 shows the high-resolution range image of the target body;

Fig. 12 shows the high-resolution range image of the target object above the low sea state sea surface;

Fig. 13 shows the high-resolution range image of the target object above the high sea state sea surface;

Figure 14 SAR imaging of the target body;

Fig. 15 shows the SAR imaging of the target body above the low sea state sea surface;

Fig. 16 shows the SAR imaging of the target body above the high sea state sea surface;

Fig. 17 shows a schematic structural diagram of a sea-skimming target multipath scattering characteristic simulation calculation system provided by an embodiment of the present invention;

Fig. 18 shows a schematic structural diagram of a sea surface sample processing module of a sea-skimming target multipath scattering characteristic simulation calculation system provided by an embodiment of the present invention.

In the figure: 10-simulation calculation system for multipath scattering characteristics of sea-skimming targets; 100-sea surface sample processing module; 110-sea surface sample processing unit; 120-binning unit; 200-scattering rate calculation module; 300-induced electromagnetic current calculation module; 400-correction module; 500-scattered field simulation module.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

Some embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

The traditional accurate electromagnetic field full-wave numerical simulation method is a solution to the problem of multipath scattering simulation. This scheme can achieve relatively accurate calculation results when calculating pure target electromagnetic scattering, but it is limited by calculation electrical scale and computational complexity when calculating real sea surface environment and target multipath scattering. The analytical method is another solution. For example, Joel T.Johnson of Ohio State University in the United States proposed a "four-path" model. The echo superposition calculation includes the direct echo of the target and the sea surface, and the coupled scattered echo through the two paths of target-sea-radar and sea-target-radar, where the scattering of the sea surface is given by the empirical scattering coefficient. Due to its simple mechanism and high simulation efficiency, this model can roughly calculate the multipath scattering of sea-skimming targets. However, the model still has limitations in complex sea conditions, because the sea surface reflection mechanism at this time is dominated by diffuse scattering, so local scattering and local coupling scattering on the sea surface need to be considered. Under complex sea conditions, the multipath scattering characteristics are very complex, which is related to the local scattering characteristics of the target and the sea surface. If the sea surface is regarded as a special "mirror", each local sea surface will produce a mirror image of the target. Please refer to Figure 2. Figure 2 shows a schematic diagram of the mirror image generated by an ultra-low-altitude point target under radar illumination. The target will generate a corresponding independent mirror image for each local surface element. The distribution of the mirror image is related to the undulation profile of the large-scale contour rough surface.

Based on the above principles, the inventor proposed a simulation calculation method for the multipath scattering characteristics of sea-skimming targets in actual work: According to the random rough surface theory and using the sea spectral function combined with the Monte Carlo method to simulate the real Ocean contour samples, and the large-scale sea surface contour is processed into bins. The scattering of the sea surface bins is calculated by the revised bin dual-scale model, and the coupling scattering between each local bin and the target is taken into account by the mirror method, and then the coherence is carried out. In this way, the multipath scattering characteristics of sea-skimming targets under various sea conditions can be accurately and efficiently simulated. Please refer to Fig. 3, Fig. 3 shows a kind of schematic flow chart of the simulation calculation method of multipath scattering characteristic of sea-skimming target provided by the embodiment of the present invention, in this embodiment, this method comprises the following steps:

S100, performing binning processing on the sea surface sample.

According to the dual-scale theory, the sea surface can be regarded as the superposition of large-scale waves and small-scale capillary waves. Therefore, the large-scale contour surface of the environment can be binned and discretized to simulate the spatial distribution of the sea surface undulation contour. In the centimeter-level radar bands such as X and Ku, the correlation of the scattering of the environmental surface is very weak, so it is considered that the scattering of each bin are non-coherent. Please refer to Fig. 4, Fig. 4 shows the schematic diagram of a kind of sea surface two-scale model provided by the embodiment of the present invention, the sea surface capillary wave structure attached on the large bin can be decomposed into the superposition of a series of space sine waves, according to the Bragg scattering theory , only the wave component along the radar line of sight and with the Bragg resonance frequency makes the main contribution to the sea surface scattering. The capillary wave component can be simplified as a monochromatic sine wave with Bragg resonance wavelength, and its expression is ξ(r)=B(κ _c )cos(κ _c ·r-ω _c t).

Among them, κ _c represents the Bragg resonance wavenumber vector, ω _c represents the angular frequency of the resonance wave, r=(x _c , y _c ) represents the position coordinates on the panel, Characterizes the amplitude of the capillary wave of Bragg scattering caused by the bin, ΔS represents the area of the small bin, and S(κ _c ) represents the high frequency part in the Elfouhaily sea spectrum.

S200. Calculate the local sea surface bin scattering rate of the sea surface sample after the binning processing by using the bin dual-scale algorithm.

Please refer to Figure 4 again. After establishing the global coordinate system on the sea surface, according to the dual-scale theory, the scattering field of the local sea surface bin of the sea surface sample includes coherent components and incoherent components, and the scattering rate of the local sea surface bin can be expressed as

in, Characterize the scattering coefficient of the coherent component of the local sea surface bin, using the Kirhoff approximation algorithm (Kirhoff Approximation, KA) to calculate and obtain, The scattering coefficient characterizing the incoherent component of the local sea surface bin is calculated and obtained by using the small perturbation method (Small Perturbation Method, SPM).

Furthermore, after the coherent component is processed by the Kirhoff approximation algorithm, the scattering rate of the local sea surface bin can be further expressed as

Among them, q represents the scattering vector, Γ _pq represents the coherent polarization scattering coefficient, and prob(·) represents the probability density function of the sea surface large-scale bin distribution.

Furthermore, after the incoherent components are processed by the perturbation method, the scattering rate of the local sea surface bin is expressed as:

Among them, F _pq represents the incoherent polarization scattering coefficient, and W _ζ (q _l ) represents the spectral distribution of the microstructure on the local sea surface bin.

Please refer to Figure 5. Figure 5 shows a schematic diagram of the sea surface bin model at a height of 10m on the sea surface when the wind speed is 3m/s. In the large-scale sea surface model generated by the Monte Carlo method based on the Elfouhaily sea spectrum, the bin size It is 1m×1m. Please refer to FIG. 6, which shows a schematic diagram of the image scattering coefficient of the sea surface element under the VV polarization condition. At this time, the radar electromagnetic wave is incident at 45° along the X-axis direction, and the frequency is 10 GHz.

S300. Obtain the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target according to the physical optics algorithm and the equivalent electromagnetic current algorithm.

Considering the surface of the target as an ideal conductor structure, the radar electromagnetic wave irradiating the surface of the target will excite the induced current on the surface of the target, and the diffraction current will be excited on the edge structure. The induced electromagnetic current is expressed as:

After subdividing the surface of the target body with plane triangular bins, the scattering field generated by the local sea surface bins in the far region is expressed as:

Wherein, ΔS characterizes the area of the plane triangle angle element, I characterizes the phase part, and

Furthermore, assuming that J _e and J _m respectively represent the equivalent current and equivalent magnetic current generated by the radar electromagnetic wave on the edge structure of the target, the expressions of the equivalent current J _e and the equivalent magnetic current J _m are respectively :

The expression of the diffraction field generated by the edge structure of the target in the far zone is:

in, The tangent vector representing the edge structure of the target body, E _i and H _i respectively represent the incident electric field and incident magnetic field generated by the radar electromagnetic wave on the edge structure of the target body, β _i and β _s respectively represent the incident direction of the radar electromagnetic wave and the target The angle generated by the edge structure of the object and the angle generated by the scattering direction of the radar electromagnetic wave and the edge structure of the target body, D _e and D _m are diffraction coefficients.

S400, correcting the image radar electromagnetic wave generated by the radar electromagnetic wave on the local sea surface bin and the image induced electromagnetic current generated by the image radar electromagnetic wave on the surface and edge structure of the target according to the scattering rate of the local sea surface bin.

Please refer to Figure 2 again. Figure 2 has shown the mirroring process of the point target and the sea surface. For the actual extended target body, each part of the target body will generate a corresponding mirroring target body for the mirror surface element when the mirroring condition is met. , at the same time, the radar as the emission source of the radar solenoid valve will also be mirrored by the mirror bin to generate the corresponding mirror source, please refer to Figure 4 again, at this time, the multipath coupling scattering between the target body and the sea surface environment is equal to the actual target body and the mirror image Superposition of object scattering.

Please refer to Fig. 7. Fig. 7 shows a schematic diagram of the bin mirroring process. The radar electromagnetic wave irradiates the target body, and the induced current generated on the target body surface is J ₁ . The target produces induced current distribution J ₂ , assuming that a certain point can mirror the sea surface element, then the image source J _1image (r _i ′ _mage ), J _2image (r _i ′ _mage ) will be generated at the mirror position, and the total scattering field is Superposition of scattering contributions from these four parts of the current distribution. therefore:

J _1image (j _ximage ,j _yimage ,j _zimage )=ρJ ₁ (j _ximage ,j _yimage ,j _zimage ),

Among them, ρ represents the mirror correction factor, and its expression is:

It is worth noting that, from the expression of the mirror correction factor, it can be seen that the mirror correction factor includes the scattering characteristics of the bin, which is mainly described by the double-scale method of the semi-determined bin, and its mirror scattering is calculated by mirror reflection distance Contribution; the modulation of capillary waves and micro-rough structures determines the details of the ground and sea surfaces, and the contribution of diffuse reflection can be calculated through the Bragg resonance theory.

S500, according to the induced electromagnetic current generated by the radar electromagnetic wave and the corrected mirror induced electromagnetic current generated by the mirrored radar electromagnetic wave, determine the scattering field generated by the radar electromagnetic wave on the surface and edge structure of the target.

In this embodiment, the result of vector summation of the induced electromagnetic current generated by the radar electromagnetic wave and the mirror image induced electromagnetic current generated by the mirrored radar electromagnetic wave is used as the Scattering fields generated by edge structures.

Please refer to FIG. 8. FIG. 8 is a schematic flow chart of the substeps of step S100 in FIG. 3. In this embodiment, step S100 includes the following substeps:

S110, according to the stochastic rough surface theory, the Monte Carlo method is used to process the Efouhaily ocean spectrum model to obtain sea surface samples.

In this embodiment, for the Efouhaily ocean spectrum model, according to the stochastic rough surface theory, the Monte Carlo method is used for preprocessing to obtain sea surface samples.

S120, performing binning processing on the large-scale contour surface of the sea surface sample.

In this embodiment, after the sea surface samples are obtained in step S110, the large-scale contours in the obtained sea surface samples are binned so as to simulate the spatial distribution of sea surface undulation contours.

In a specific implementation, it is assumed that the frequency of the radar electromagnetic wave is 10 GHz, the target is a "Tomahawk" cruise missile, and the incident angle generated by the radar electromagnetic wave irradiating the target is 45°. Please refer to FIG. 9. FIG. 9 shows the calculation result of HH polarization in multipath scattering calculation. Please refer to FIG. 10. FIG. 10 shows the calculation result of VV polarization in multipath scattering calculation. It can be seen that when the target is flying low, the multipath effect has an obvious enhancement effect on the backscatter of the radar; moreover, when the target height is low, this enhancement effect is more obvious; moreover, the enhancement of HH polarization is also Stronger than VV polarization.

In order to further understand the influence of multipath scattering on the target radar scattering characteristics, we continue to use this method to simulate the high-resolution range image of the radar. Please refer to Figure 11, Figure 12 and Figure 13. Figure 11 shows the high-resolution range image of the target For the range image, Fig. 12 shows the high-resolution range image of the target object above the low sea state sea surface, and Fig. 13 shows the high resolution range image of the target object above the high sea state sea surface. At this time, we adopt the signal form of frequency step, the radar bandwidth is 350MHz, the frequency step interval is 3.5MHz, and the radar polarization is HH polarization. It can be seen that when the target is flying low, the multipath effect on the radar The distance image also has a big impact. In the range image of the pure target body, we can clearly distinguish the three main strong scattering points with different intensities on the head, wing and tail of the cruise missile. In the low sea state sea surface, we select the wind speed at 10m above the sea surface in the sea spectrum function as 5m/s. It can be seen that the intensity of multipath interference at this time is greater, which will submerge most of the scattering points of the target body, resulting in the detection and identification of the target. difficulty. In high sea conditions and sea surface, the wind speed is 10m/s. At this time, the multipath scattering intensity becomes smaller, and the energy is relatively scattered, and more scattering points of the original target can be identified.

In order to further observe the multipath scattering characteristics, please refer to Figure 14, Figure 15 and Figure 16, Figure 14 shows the SAR imaging of the target object, Figure 15 shows the SAR imaging of the target object above the sea surface in low sea state, and Figure 16 shows the target object In the SAR imaging above the high sea state, the SAR adopts the airborne front-side simulation model. It can be seen that in the low sea state situation, we can see the mirror false target caused by the multipath effect. When the sea is clear, the false target strength is obvious. weakened.

Based on the above design, the embodiment of the present invention provides a simulation calculation method for the multipath scattering characteristics of sea-skimming targets, which simulates the real ocean contour at each quasi-static moment by using the random rough surface theory combined with the sea spectral function and the Monte Carlo method At the same time, the large-scale sea surface profile is processed into bins, and the scattering of the sea surface bins is calculated by the revised binning dual-scale model, and the coupling scattering between the local bins and the target is taken into account in combination with the mirror image method, and then coherently superimposed. Accurately and efficiently simulate the multipath scattering characteristics of targets above the sea surface in complex sea conditions. Compared with traditional calculation models and methods, it can reflect the local coupling scattering characteristics of the sea surface and targets, so that the multipath of sea-skimming targets can be calculated more accurately and efficiently. Scattering, and it is easier to apply to observe the characteristics of multipath scattering on one-dimensional image of sea surface target, SAR image and so on.

Please refer to FIG. 17. FIG. 17 shows a schematic structural diagram of a sea-skimming target multipath scattering characteristic simulation calculation system 10 provided by an embodiment of the present invention. In this embodiment, the sea-skimming target multipath The scattering characteristic simulation calculation system 10 includes a sea surface sample processing module 100 , a scattering rate calculation module 200 , an induced electromagnetic current calculation module 300 , a correction module 400 and a scattering field simulation module 500 . in,

The sea surface sample processing module 100 is used for binning the sea surface samples.

The scatter rate calculation module 200 is used to calculate the local sea surface bin scatter rate of the binned sea surface sample by using a binning double-scale algorithm.

The induced electromagnetic current calculation module 300 is used to obtain the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target according to the physical optics algorithm and the equivalent electromagnetic current algorithm.

The correction module 400 is used to analyze the image radar electromagnetic wave generated by the radar electromagnetic wave on the local sea surface bin and the image radar electromagnetic wave on the surface and edge structure of the target according to the scattering rate of the local sea surface bin. The generated mirror induced electromagnetic current is corrected.

The scattered field simulation module 500 is used to determine the surface and edge of the radar electromagnetic wave on the surface and edge of the target according to the induced electromagnetic current generated by the radar electromagnetic wave and the corrected image induced electromagnetic current generated by the mirrored radar electromagnetic wave. Scattering fields generated by structures.

Please refer to FIG. 18. FIG. 18 shows a schematic structural diagram of a sea surface sample processing module 100 of a sea-skimming target multipath scattering characteristic simulation calculation system 10 provided by an embodiment of the present invention. In this embodiment, The sea surface sample processing module 100 includes a sea surface sample processing unit 110 and a binning unit 120 . in,

The sea surface sample processing unit 110 is used to process the Efouhaily sea spectrum model by using the Monte Carlo method according to the stochastic rough surface theory, so as to obtain sea surface samples.

The binning unit 120 is used for binning the large-scale contour surface of the sea surface sample.

To sum up, the embodiment of the present invention provides a method and system for simulating and calculating the multipath scattering characteristics of sea-skimming targets. By using random rough surface theory combined with sea spectral function and Monte Carlo method to simulate Real ocean contour samples, and large-scale sea surface contours are processed into bins at the same time. The scattering of the sea surface bins is calculated by the revised binning dual-scale model, and the coupling scattering between the local bins and the target is taken into account in combination with the mirror image method, and then coherent Superposition can accurately and efficiently simulate the multipath scattering characteristics of complex sea conditions and multi-scale targets above the sea surface. Compared with traditional calculation models and methods, it can reflect the local coupling scattering characteristics of the sea surface and targets, so that the sea-skimming targets can be calculated more accurately and efficiently. multipath scattering, and it is easier to apply to observe the characteristics of multipath scattering on one-dimensional image of sea surface target, SAR image and so on.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims (10)

1. A sea-skimming target multipath scattering characteristic simulation calculation method, is characterized in that, described method comprises: Perform binning processing on sea surface samples; Using a binning double-scale algorithm to calculate the local sea surface bin scattering rate of the sea surface sample after the binning process; According to the physical optics algorithm and the equivalent electromagnetic current algorithm, the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target is obtained; According to the scattering rate of the local sea surface bin, the image radar electromagnetic wave generated by the radar electromagnetic wave on the local sea surface bin and the image induced electromagnetic wave generated by the image radar electromagnetic wave on the surface and edge structure of the target flow is corrected; According to the induced electromagnetic current generated by the radar electromagnetic wave and the corrected image induced electromagnetic current generated by the mirrored radar electromagnetic wave, the scattering field generated by the radar electromagnetic wave on the surface and edge structure of the target is determined. 2. method as claimed in claim 1, is characterized in that, the step that described sea surface sample is carried out binning process, comprises: According to the stochastic rough surface theory, the Monte Carlo method is used to process the Efouhaily sea spectrum model to obtain sea surface samples; Perform binning processing on the large-scale contour surface of the sea surface sample. 3. The method according to claim 1, wherein, according to the dual-scale theory, the scattering field of the local sea surface bin of the sea surface sample comprises a coherent component and an incoherent component, and the scattering rate of the local sea surface bin represents for: in, The scattering coefficient representing the coherent component of the local sea surface bin is obtained by using the Kirhoff approximation algorithm, The scattering coefficient representing the incoherent component of the local sea surface bin is obtained by a perturbation method. 4. method as claimed in claim 3, is characterized in that, after adopting Kirhoff approximate algorithm to process described coherent component, the scattering rate of described local sea surface bin is expressed as: Among them, q represents the scattering vector, Γ _pq represents the coherent polarization scattering coefficient, and prob(·) represents the probability density function of the sea surface large-scale bin distribution. 5. method as claimed in claim 4, is characterized in that, after adopting perturbation method to process described incoherent component, the scattering rate of described local sea surface bin is expressed as: Among them, F _pq represents the incoherent polarization scattering coefficient, and W _ζ (q _l ) represents the spectral distribution of the microstructure on the local sea surface bin. 6. method as claimed in claim 1, is characterized in that, the induction electromagnetic current that described radar electromagnetic wave produces on the surface of target body and edge structure is expressed as: After the surface of the target body is subdivided by plane triangular bins, the scattering field generated by the local sea surface bins in the far region is expressed as: Wherein, ΔS characterizes the area of the plane triangle angle element, I characterizes the phase part, and 7. method as claimed in claim 6, is characterized in that, the expression of equivalent electric current J _e and equivalent magnetic current J _m that described radar electromagnetic wave produces at the edge structure of described target body is respectively: The expression of the diffraction field produced by the edge structure of the target body in the far zone is: in, Characterize the tangent vector of the edge structure of the target body, E _i and H _i respectively represent the incident electric field and the incident magnetic field generated by the radar electromagnetic wave at the edge structure of the target body, and β _i and β _s respectively represent the The angle between the incident direction of the radar electromagnetic wave and the edge structure of the target body and the angle between the scattering direction of the radar electromagnetic wave and the edge structure of the target body, D _e and D _m are Diffraction coefficient. 8. The method according to claim 1, wherein, according to the induced electromagnetic current generated by the radar electromagnetic wave and the mirror induced electromagnetic current generated by the mirrored radar electromagnetic wave, it is determined that the radar electromagnetic wave is in the The steps of the scattered field generated by the surface and edge structure of the target body include: The result of vector summation of the induced electromagnetic current generated by the radar electromagnetic wave and the mirror induced electromagnetic current generated by the mirrored radar electromagnetic wave is used as the scattering of the radar electromagnetic wave on the surface and edge structure of the target field. 9. A sea-skimming target multipath scattering characteristic simulation calculation system, characterized in that the system includes: The sea surface sample processing module is used for binning the sea surface samples; A scatter rate calculation module, configured to calculate the local sea surface bin scatter rate of the sea surface sample after binning processing by using a binning double-scale algorithm; The induced electromagnetic current calculation module is used to obtain the induced electromagnetic current generated by the radar electromagnetic wave on the surface and edge structure of the target according to the physical optics algorithm and the equivalent electromagnetic current algorithm; A correction module, configured to analyze the image radar electromagnetic wave generated by the radar electromagnetic wave on the local sea surface bin and the image radar electromagnetic wave on the surface and edge structure of the target according to the scattering rate of the local sea surface bin The generated mirror induced electromagnetic current is corrected; The scattering field simulation module is used to determine the radar electromagnetic wave on the surface and edge of the target according to the induced electromagnetic current generated by the radar electromagnetic wave and the corrected image induced electromagnetic current generated by the mirror image radar electromagnetic wave Scattering fields generated by structures. 10. system as claimed in claim 9, is characterized in that, described sea surface sample processing module comprises: The sea surface sample processing unit is used to process the Efouhaily sea spectrum model with the Monte Carlo method according to the stochastic rough surface theory to obtain sea surface samples; The binning unit is used to bin the large-scale contour surface of the sea surface sample.