KR20190059384A - Apparatus and method for measuring of radar cross section based on physical theory of diffraction - Google Patents

Abstract

Provided are an apparatus for measuring a radar cross section and a method thereof, estimating first and second surface current induced at an illumination region and a corner region of a scatterer by an incident electromagnetic wave using an approximation method of the physical optics and an approximation method of the physical theory of diffraction, estimating a third surface current induced into a dead region of the scatterer based on a first electromagnetic value by the first surface current estimated through the approximation method of the physical optics, a second electromagnetic value by the second surface current estimated through the approximation method of the physical theory of diffraction and a third electromagnetic value by the incident electromagnetic wave, calculating a first scattered electric field by repetitively calculating an initial surface current value resulted by summing the first and the third surface current through the repetitive approximation method of the physical optics based on a preset magnetic field integral equation, and calculating the total scattered wave electric field by summing the first scattered electric field with a second scattered electric field based on the second surface current, to measure the radar cross section. The present invention can enhance accuracy in measuring the radar cross section of the scatterer.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an apparatus and a method for measuring a radar reflection area based on physical optical diffraction theory,

The present invention relates to a method of measuring a radar cross section (RCS) of a scatterer by applying an iterative physical optics (IPO) technique and a physical theory of diffraction (PTD) And more particularly,

In aerospace systems, EMC, such as antenna to antenna coupling, antenna placement near large structures, and cross talk problems between cables, (Electro-Magnetic Compatibility) / EMI (Electro-Magnetic Interference). In particular, predicting scattering by a large-scale object is a very important problem at the present technology level because it requires a large amount of calculation and memory usage for the calculation.

For example, after a radar applies electromagnetic waves to a target, the signal returned from the target is not an optical image that a human can see visually, but a radar cross section (RCS [m ² ]). In this case, RCS means the degree of reflection of the electromagnetic wave of the object. The RCS is the ratio between the power [W] of the scattered wave that is returned from the electromagnetic waves transmitted from the radar and scattered by the object, and the power density [W / m ² ] Ratio. In other words, the target is related to the amount of electromagnetic waves scattering in the direction of the radar, and the stealth fighter, which is generally talked about as a low-RCS fighter.

In this regard, Korean Patent Registration No. 2014-0011153 (entitled "Radar Cross Sectional Area Measurement Apparatus and Measurement Method Using the Same") discloses that the radar cross sectional area of a measurement object is measured in a general environment in which reflection exists A radar cross sectional area value of the reflector corresponding to the radiation pattern of the antenna is calculated and the antenna is rotated in the measurement area with respect to the reflector and the measurement target, Sectional area value of a reflector according to the present invention and the radar reflection sectional area value of the object to be measured are deconvoluted with the reflector cross sectional area value of the reflector and the reflector and the radar reflection sectional area value of the object to be measured, have.

Conventionally, in order to numerically simulate the RCS of a large scale object, a typical high frequency approximation method called Physical Optics (PO) is used. In other words, the induced current (surface current) on the surface of the scattering body was predicted by the incident wave using the PO method and the scattering wave was calculated based on the predicted current. The accuracy of the final scattered wave is proportional to the accuracy of the predicted surface current. However, the accuracy of the PO method is negligible because it neglects the surface currents that can be induced in the multiple reflections of the scatterer, the diffraction at the edges, and the shadow area. In addition, the Iterative Physical Optics (IPO) technique improves the accuracy of the PO method by including multiple reflections of the scatterer, but the other components described above (i.e., The surface current that can be ignored) is still negligible.

Embodiments of the present invention solve the problems of the conventional art described above. The present invention provides a method of estimating a scattered wave by calculating multiple scattered waves considering diffracted waves diffracted not only in a reflection area of an illuminated area of a scatterer but also in a shadow area, , And an apparatus and method for measuring a high accuracy radar reflection area (RCS).

It should be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may exist.

According to an aspect of the present invention, there is provided an apparatus for measuring a radar reflection area according to an aspect of the present invention, comprising: a memory for storing a radar reflection area measurement program; And a processor for executing a program stored in the memory, wherein the processor is configured to perform a predetermined physical-optics (PO) approximation method and a physical theory of diffraction (PTD) ) Approximation method to estimate the surface current induced in the illumination region and the edge region of the scatterer by an incident electromagnetic wave respectively and to estimate the surface current induced in the first region by the first surface current estimated through the PO- Estimates a third surface current induced in the shaded region of the scatterer based on a magnetic field value, a second magnetic field value due to the second surface current estimated through the PTD approximation method, and a third magnetic field value due to the incident electromagnetic wave , The initial value of the surface current according to the sum of the first and third surface currents is set to a preset Magnetic Field Integral Equation (MFIE) ) Based on the first scattered wave electric field and the second scattered wave electric field based on the second surface electric current to calculate a total scattered wave electric field by summing the first scattered wave electric field and the second scattered wave electric field based on the second surface electric current, The repeating operation according to the IPO is stopped and the repeating procedure is suspended at the moment when the current size diverges.

A method of measuring a radar reflection area using a radar reflection area measuring apparatus according to another aspect of the present invention uses a predetermined physical optical (PO) approximation method and a physical theory of diffraction (PTD) approximation method Estimating a surface current induced in an illumination region and an edge region of a scatterer by an incident electromagnetic wave; Based on the first magnetic field value by the first surface current estimated through the PO approximation method, the second magnetic field value by the second surface current estimated by the PTD approximation method, and the third magnetic field value by the incident electromagnetic wave, Estimating a third surface current induced in a shadow region of the scatterer; The initial value of the surface current according to the sum of the first and third surface currents is subjected to iterative calculation processing through an iterative physical optics (IPO) approximation method based on a predetermined magnetic field integral equation (MFIE) 1) calculating a scattering wave field; And calculating a total scattered wave electric field by summing the first scattered wave electric field and a second scattered wave electric field based on the second surface electric current, and repeating an instant repetition procedure in which the current size diverges during the repeated calculation process according to the IPO do.

According to the above-mentioned object of the present invention, the RCS is measured by applying a repetitive physical optical (IPO) method, which is effective for calculating scattering by a large and complex object (i.e., scattering body) such as an aircraft, And PTD technique, it is possible to calculate the RCS considering the diffracted wave diffracted to the shadow region of the scattering body. Thus, the accuracy of the scatterer RCS measurement result can be greatly improved.

According to a preferred embodiment of the present invention, the IPO technique applied in RCS measurement can be applied to a Jacobi, Gauss-Seidel, Successive Over Relaxation (SOR) By using at least one of the iterative method and the Richardson iteration method, the convergence can be controlled in the IPO calculation.

1 is a configuration diagram of a radar reflection area measuring apparatus according to an embodiment of the present invention.
FIG. 2 is a view for explaining a method of modeling a scatterer surface current according to an embodiment of the present invention. Referring to FIG.
3 is a view showing an example of a scattering body to which an embodiment of the present invention is applied.
4 and 5 are views for explaining a multiple scattered wave estimation method using the PO technique and the IPO technique according to an embodiment of the present invention.
FIG. 6 is a view for explaining a diffraction wave estimation method using the PTD technique according to an embodiment of the present invention.
7 is a view for explaining a surface current estimation method at a corner of a scatterer according to the PTD technique according to an embodiment of the present invention.
FIG. 8 is a flowchart for explaining a method of measuring a radar reflection area considering both reflected waves and diffracted waves according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as " comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

1 is a configuration diagram of a radar reflection area measuring apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the radar reflection area measuring apparatus 100 includes a memory 110 and a processor 120.

The memory 110 stores a radar reflection area measurement program for measuring the RCS of the scatterer using the PO approximation method, the PTD approximation method, and the IPO method.

In the memory 110, physical characteristic values of a predetermined type may be stored as data data for the various scatterers, and these data data are used by the processor 120 to estimate the RCS corresponding to the physical characteristics of the object .

The processor 120 executes the program stored in the memory 110, and performs the following processing according to the execution of the radar reflection area measurement program.

The processor 120 uses an incident electromagnetic wave using a predetermined physical optics (PO) approximation method and a physical theory of diffraction (PTD) approximation method to determine the illumination area of the scatterer And the surface current induced in the edge region, respectively.

The processor 120 calculates a first magnetic field value by the first surface current estimated through the PO approximation method, a second magnetic field value by the second surface current estimated by the PTD approximation method, and a third magnetic field value by the incident electromagnetic wave And estimates a third surface current induced in the shadow region of the scatterer.

The processor 120 then computes the surface current initial values according to the sum of the first and third surface currents in accordance with the Iterative Physical Optics (IPO) approximation method based on a predetermined Magnetic Field Integral Equation (MFIE) And the first scattered wave field is calculated. At this time, the processor 120 stops the momentary repetition process when the current size diverges in the iterative calculation process according to the IPO.

Next, the processor 120 calculates the total scattered wave electric field by summing the second scattered wave electric field based on the first scattered wave electric field and the second surface electric current.

2 to 7, the process of numerically modeling the scatterer surface current by the processor 120 as described above will be described in detail.

FIG. 2 is a view for explaining a method of modeling a scatterer surface current according to an embodiment of the present invention. Referring to FIG. 3 is a view showing an example of a scattering body to which an embodiment of the present invention is applied.

When an electromagnetic wave is incident on the scattering body, the radio wave observed at an arbitrary point is propagated in the absence of the scattering body (that is, incident wave) and in the presence of the scattering body, (I.e., a scattered wave) that is transmitted through the antenna. As shown in Fig. 2, an area where an incident wave reaches (that is, an illumination area (lit-region)) and an area where an incident wave is blocked (i.e., a shadow area) , It is possible to estimate the current induced on the surface of the scattering body by the incident electromagnetic wave. At this time, the current induced in the surface of the illuminated area and the shaded area of the scatterer generates a reflected wave, and the current induced in the edge area of the scatterer generates a diffracted wave. That is, scattered waves (reflected waves + diffracted waves) are generated as a whole. For reference, the overall scattered wave can be obtained by integrating electric currents and magnetic currents on the surface of the scatterer.

In an embodiment of the present invention, it is assumed that the size of the scatterer is large and the surface is smooth enough, so that the surface of the scatterer can be regarded as a locally infinite plane. Accordingly, in order to estimate the structure of the scatterer, the processor 120 discretizes the surface of the scatterer into a specific basic shape (for example, small triangles) Can be calculated. At this time, the required surface integral for each basic shape of the scatterer can be computed numerically using Gauss quadrature.

Specifically, the processor 120 calculates the surface current initial value of the scatterer using the PO approximation method and the PTD approximation method. Hereinafter, the surface current estimated by the PO approximation method is referred to as J _PO , which is the initial surface current primarily induced by the incident wave in the illumination region of the scatterer. Also, the surface current estimated by the PTD approximation is referred to as J _PTD , which is the surface current induced in the edge region by the incident wave of the scatterer. Diffracted waves are generated by the J _PTD , which is one condition for inducing the surface current in the shadow region.

In FIG. 3, the scattering body applied to an embodiment of the present invention is an airplane tail blade. Referring to FIG. 3, it can be seen that a surface current induced in an illumination region of an airplane tail wing generates a scattered field by an incident wave, and a surface current induced in an edge region generates a diffracted filed . In this case, surface currents that generates a scattered wave has, J _PO and the surface current (hereinafter, J _x as hereinafter), the surface current initial value with the one IPO current estimated by processing a repeated operation by IPO approximations introduced in the shaded area (the , _{Referred to} as J _IPO ).

First, 4 and 5 to be described the procedure for calculating J in _IPO J _PO, and _PO is set to J as a surface current initial value.

4 and 5 are views for explaining a multiple scattered wave estimation method using the PO technique and the IPO technique according to an embodiment of the present invention.

와 자계(magnetic field)

로 정의되는 입사파(incident field)가 모서리(wedge) 형상의 산란체에 입사되면, 먼저 산란체의 조명 영역에서 PO 전류(즉, J_PO )를 여기하고 1차 반사된다. 그리고 1차 반사된 반사파는 산란체의 조명 영역 상에서 반복적으로 반사(즉, 다중 반사)되므로 반복적으로 PO 전류를 업데이트한다. 즉, MFIE에 기반하여 반사파에 의한 표면 전류를 반복적으로 연산하여 IPO 전류를 산출함으로써 조명 영역에서의 반사파를 산출할 수 있다.Referring to FIGS. 4 and 5, an electro-

And a magnetic field.

Is incident on the wedge-shaped scattering body, the PO current (that is, J _PO ) is first excited in the illumination region of the scattering body and is firstly reflected. The reflected primary reflected light is repeatedly reflected (that is, multiple reflected) on the illuminated area of the scattering body, so that the PO current is repeatedly updated. That is, the reflected wave in the illumination region can be calculated by calculating the IPO current by repeatedly calculating the surface current by the reflected wave based on the MFIE.

The total current on the surface of the scatterer can be approximated by the sum of the incident wave and the scattered wave as shown in Equation 1 below.

&Quot; (1) "

는 산란체 표면 전류이고,

는 입사 자계이고,

는 반사 자계이며,

은 산란체 표면 밖으로 향하는 단위법선벡터(unit normal vector)이다.In Equation (1)

Is the scatterer surface current,

Is an incident magnetic field,

Is a reflection magnetic field,

Is a unit normal vector that points out of the scatterer surface.

Based on this, it is possible to approximate J _PO by using the PO approximation method as shown in Equation 2 below.

&Quot; (2) "

로 표시하였으며, 음영 영역에서의 전류 값은 0인 것을 가정하는 것을 나타냈다.In Equation (2), J _PO is actually the first current value of the IPO process

And that the current value in the shaded region is assumed to be zero.

On the other hand, surface currents due to repetitive reflected waves after J _PO can be approximated as shown in Equation (3).

&Quot; (3) "

은 n번째 차수로 업데이트되는 표면 전류이다. 그리고

은 반사파를 유도하는 소스 표면 전류

부터 반사파에 의해 발생된 타겟 표면 전류

까지의 벡터 값(즉, 관측점의 위치 벡터)이다. 그리고 R은

이며, k₀는 자유 공간의 파수로서

이고, c는 광속이며, f₀는 관심 주파수(frequency of interest)이다. In Equation 3,

Is the surface current updated to the nth order. And

Is the source surface current

The target surface current generated by the reflected wave

(I.e., the position vector of the viewpoint). And R is

And k ₀ is the wave number of the free space

, C is the speed of light, and f ₀ is the frequency of interest.

That is, if J _PO and J _IPO as described above are expressed based on the magnetic field integral equation (MFIE), they are expressed by the following equations (4) and (5), respectively.

 &Quot; (4) "

Equation (5)

은 표면 전류의 위치 벡터이고, 적분은 코시의 원칙에 따른 값(Cauchy’s principle value)이다.At this time, in equations (4) and (5)

Is the position vector of the surface current, and the integral is the Cauchy's principle value.

On the other hand, the IPO method can predict the surface current using an iterative method according to Equations (6) and (7) as follows. At this time, the Jacobi repeating method is applied to the iterative method according to the following equations (6) and (7).

&Quot; (6) "

&Quot; (7) "

일 때

은 일반적으로 발산한다. 따라서, 프로세서(120)는 전류 크기가 최초 지엽적 최소값(first local minimum)에 이르면 반복 절차를 중지시켜 수렴성을 조절한다.The convergence in Equation (7) can be guaranteed when the size of the scatterer is small. That is, when the size of the scatterer is very large,

when

Generally diverge. Thus, the processor 120 stops the iterative process and adjusts the convergence when the current magnitude reaches the first local minimum.

Specifically, the scattered wave at the far-field is calculated using a Hertz vector. The Hertz vector is represented by the following equation (8).

&Quot; (8) "

In Equation (8), Z ₀ is a characteristic impedance on free space. At this time, the electric field of the scattered waves is represented by the following equation (9).

&Quot; (9) "

The resulting scattering matrix is expressed as shown in Equation (10).

&Quot; (10) "

In Equation 10, the subscript h means horizontal polarization (h-pol), and the subscript v means vertical polarization (v-pol).

The processor 120 may calculate the radar reflection area of the scatterer according to Equation (11) below.

Equation (11)

In Equation (11), m and n represent h or v as in Equation (10).

Equations (6) and (7) are surface current calculation expressions based on Jacoby iteration. However, the processor 120 can adjust the convergence of the IPO by calculating the radar reflection area of the scatterer using an iterative method having the same or different convergence conditions as the Jacobi repeating method.

The following Gauss-Giddel iteration, SOR iteration and Richardson iteration can be used to calculate the radar reflection area.

First, Equation (5) can be expressed as Equation (12) and Equation (13).

&Quot; (12) "

&Quot; (13) "

Here, I denotes an identity matrix and L ₁ denotes an integral operator of Equation (3). And L = I + L ₁ .

At this time, if the matrix L is divided by the diagonal matrix W and the non-diagonal matrix R, L = W-R, and the equation (13) can be expressed by the following equation (14).

&Quot; (14) "

를 계산하기 위해, 자코비(Jacobi) 반복법을 사용하면 다음 수학식 15와 같이 표현될 수 있다.W = I in the MFIE, and

Using the Jacobi iteration method can be expressed by the following equation (15).

&Quot; (15) "

Here, when a Gauss-Seidel iteration is applied, the matrix L is divided into a diagonal matrix, a lower triangular matrix E, and an upper triangular matrix F. That is, L = W-E-F.

Accordingly, Equation (13) can be expressed as Equation (16).

&Quot; (16) "

Thus, the Gauss-Gedle iteration is defined as: " (17) "

&Quot; (17) "

를 산출할 수 있다.On the other hand, the convergence condition of the Gauss-Giddel iteration is the same as the Jacoby iteration, but since convergence and divergence are twice the Jacoby iteration,

Can be calculated.

Also, the SOR iterative method may be used to improve the convergence speed of the Gauss-Gedel iteration. The SOR iteration is one of the relaxation methods and can be implemented by modifying the Gauss-Giedel iteration.

This SOR iteration method can be expressed by the following Equation (18).

&Quot; (18) "

는 가중치이다. 참고로,

= 1 이면, 수학식 18은 가우스-지델 반복법과 동일하다. 따라서,

를 조절하여 SOR 반복법은 가우스-지델 반복법에 비해 수렴 속도를 개선할 수 있다.At this time, GS is the result of the Gauss-Giedel iteration,

Is the weight. Note that,

= 1, Equation (18) is the same as Gauss-Gedle iteration. therefore,

The SOR iterative method can improve the convergence speed as compared with the Gauss-Gedle iteration method.

By the way, if the area is a large scattering chain, it can emit almost all of the time at IPO, so it is possible to use an iterative method that can approach the improved solution even if it is slower than the SOR iterative method which focuses on speeding up possible convergence speed.

를 조절하여 수렴 속도를 개선할 수 있다.Richardson iterations can slow down convergence. This Richardson iteration method can improve the accuracy of the final calculated surface current at IPO. For reference, Richardson iteration also works with SOR iterations.

The convergence speed can be improved.

The Richardson iteration method is expressed by the following equations (19) and (20).

&Quot; (19) "

&Quot; (20) "

On the other hand, as described above, the processor 120 uses the sum of J _PO and J _x as the initial value of the surface current of _IPO in calculating J _IPO .

That is, J _PO And J _x acts as a source to repeatedly excite the surface current J _IPO and multiply reflect (i.e., iteratively reflect).

At this time, J _x can be estimated as the surface current of the shaded region by the following expression (21).

&Quot; (21) "

는 산란체의 모서리에 의하여 회절되는 자계이고,

는 산란체의 조명 영역에 여기된 J_PO에 의해 투과되는 자계이며,

는 산란체에 입사되는 자계(즉, 입사파의 자계)이다.In Equation 21,

Is a magnetic field that is diffracted by the corners of the scatterer,

Is a magnetic field transmitted by J _PO excited in the illumination region of the scatterer,

Is a magnetic field (that is, a magnetic field of an incident wave) incident on the scattering body.

Hereinafter, the process of calculating J _PTD will be described with reference to FIGS. 6 and 7. FIG.

FIG. 6 is a view for explaining a diffraction wave estimation method using the PTD technique according to an embodiment of the present invention. And FIG. 7 is a diagram for explaining a surface current estimation method at a corner of a scatterer according to the PTD technique according to an embodiment of the present invention.

As shown in Fig. 6, diffraction occurs at the edge of the scattering body, and the surface current of the corner region excites the surface current J _PTD and is first diffracted.

방향으로 입사하고, 산란파를

방향에서 관측할 경우, 곡선을 짧은 직선 형태의 모서리들로 차분화하면 n 번째 직선 모서리는

의 위치에 놓인다. 이때, 전체 모서리에 의한 회절파는 각각의 촤분화된 모서리에 의한 회절파들의 합이다.More specifically, as shown in FIG. 7,

Direction, and a scatter wave

If you observe in the direction, if you divide the curve into short straight-line corners, the nth straight-line corner

. At this time, the diffraction wave due to all the corners is the sum of the diffraction waves due to the respective differentiated edges.

At this time, the global coordinates are converted into local coordinates to apply the PTD approximation.

The electric field in the corner area of the scatterer can be obtained by the following equation (22).

&Quot; (22) "

는 J_PTD에 의한 회절파의 전계이고,

는 이산화된 세그먼트의 기여도이며, D는 기설정된 회절계수(diffraction coefficients)이고, L은 이산화된 세그먼트의 길이이고, r은 세그먼트로부터 관측지점까지의 거리이고, Z₀는 자유 공간의 고유 임피던스이며,

은 모서리를 따른 접선 단위 벡터이다.In Equation 22,

Is the electric field of the diffracted wave by J _PTD ,

Where D is the predetermined diffraction coefficients, L is the length of the discretized segment, r is the distance from the segment to the observation point, Z ₀ is the intrinsic impedance of the free space,

Is a tangential unit vector along an edge.

및 자기적 성분

을 산출할 수 있다.Since the surface current of the scattering body exists together with the electric component e and the magnetic component m, the electric component of J _PTD

And a magnetic component

Can be calculated.

&Quot; (23) "

는 비균일 전류(non-uniform current)의 전기적 성분

로부터 J_PO 의 전기 전류

를 제한 값이고,

는 비균일 전류의 자기적 성분

로부터 J_PO 의 자기 전류

를 제한 값이다.At this time,

Is an electrical component of a non-uniform current

The electric current of J _PO from

Lt; / RTI >

Is a non-uniform current magnetic component

The magnetic current of J _PO

Is a limiting value.

, ,

및

는 각각 아래의 수학식 24 내지 27과 같이 나타낼 수 있다.

, ,

And

Can be expressed by the following equations (24) to (27), respectively.

&Quot; (24) "

&Quot; (25) "

&Quot; (26) "

&Quot; (27) "

이고,

이며,

이다.Referring to Fig. 7 (b)

ego,

Lt;

to be.

Accordingly, Equation (22) can be expressed as Equation (28).

&Quot; (28) "

The initial value of the IPO approximation method (i.e., the initial value of the surface current) can be calculated using the PO current and the PTD current calculated according to the above process, as shown in the following equation (29).

&Quot; (29) "

이고,

은 입사 자계이며,

이고,

이다.At this time,

ego,

Is an incident magnetic field,

ego,

to be.

및

)에 의해 발생된 회절파의 자계는 다음의 수학식 30을 통해 산출할 수 있다.Then, the PDT current (i.e.,

And

) Can be calculated by the following equation (30). &Quot; (30) "

&Quot; (30) "

이고,

이고,

이다.At this time,

ego,

ego,

to be.

As described above, the processor 120 is configured to receive the J _PO And the initial value of the surface current according to the sum of J _x is used for the _IPO to estimate J _IPO and the reflected wave electric field of the illuminated area and shaded area of the scatterer is calculated based on J _IPO . Then, the processor 120 calculates the electric field of the diffraction wave in the corner region of the scatterer based on J _PTD . Then, the processor 120 calculates the total scattered wave field by summing the electric fields of the respective scattered waves (that is, the reflected wave and the diffracted wave) in the illumination area, the shaded area and the edge area.

The processor 120 calculates the radar reflection area of the scatterer based on the amplitude ratio of the power of the scattered wave electric field and the incident electromagnetic wave.

At this time, the processor 120 may store the radar reflection area calculated in the memory 110 as the scattering body identification reference information by matching with the incident electromagnetic wave, and a variable according to a predetermined physical property is applied to each of the plurality of scattering bodies The radar reflection area can be calculated and stored.

Meanwhile, the memory 110 stores reflection coefficients and diffraction coefficients set corresponding to physical characteristics of at least one of size, shape, and medium for each of a plurality of types of scatterers. Accordingly, the processor 120 may apply the reflection coefficient and the diffraction coefficient corresponding to the scatterers to the PO, IPO, and PTD approximation methods.

In addition, the processor 120 detects a corresponding size range of a size value according to the shape of the corresponding scatterer among a plurality of scatterer size ranges set in advance, and determines at least one of the previously matched IPO approximation methods to the detected size range You can also choose to process iterative operations.

1, the radar reflection area measuring apparatus 100 further includes a transceiver 130 that emits predetermined electromagnetic waves toward an arbitrary direction and measures scattered waves corresponding to the transmitted electromagnetic waves .

At this time, the processor 120 detects the incident electromagnetic wave and the radar reflection area corresponding to the electromagnetic wave and the scattered wave measured through the transceiver 130 among the scatterer identification reference information stored in the memory 110, and identifies the object .

8 is a flowchart illustrating a method of measuring a radar reflection area according to an embodiment of the present invention.

First, the surface currents induced in the illumination area and the edge area of the scatterer are respectively calculated by the incident electromagnetic waves using the PO approximation method and the PTD approximation method, and the first magnetic field value based on the first surface current estimated through the PO approximation method, PTD A third surface current induced in the shaded region of the scatterer based on the second magnetic field value due to the second surface current estimated through the approximation method and the third magnetic field value due to the incident electromagnetic wave is calculated S110 and 210.

Then, the initial value of the surface current according to the sum of the first and third surface currents is repeatedly processed through the IPO approximation method based on the MFIE (S120).

At this time, the instant when the current size diverges in the iterative calculation process according to the IPO is detected (S130), and the iterative procedure is stopped (S140).

For reference, as the IPO technique, the iterative operation can be processed using at least one of Jacobi, Gauss-Seidel, Successive Over Relaxation (SOR), and Richardson iteration.

In addition, a size range corresponding to a size value according to the shape of the scatterer may be detected from among a plurality of scatterer size ranges set in advance, and at least one of the IPO approximation methods previously matched to the detected size range may be selected, . ≪ / RTI >

The first scattered wave (i.e., reflected wave) electric field is calculated (S150) based on the surface current values of the illuminated area and the shaded area of the scatterer calculated through the above steps S120 to S140, The second scattered wave (i.e., diffraction wave) electric field is calculated based on the surface current value of the corner area of the scatterer calculated through the first scattered wave (S210) (S220).

Next, the total scattered wave electric field is calculated by summing the first scattered wave electric field and the second scattered wave electric field (S160).

According to an embodiment of the present invention, there is provided a method of calculating a radar reflection area of a scatterer, comprising the steps of: calculating a radar reflection area of the scatterer based on the amplitude ratio of the total scattered wave electric field and the incident electromagnetic wave power after the step (S160) And storing the scattering body identification reference information as the scattering body identification reference information by matching with the incident electromagnetic wave. At this time, the radar reflection area can be calculated and stored by applying a variable according to predetermined physical characteristics to a plurality of kinds of scatterers.

Also, before estimating the surface currents induced in the illumination region and the edge region, the reflection coefficient and the diffraction coefficient set corresponding to the physical characteristics according to at least one of size, shape, and medium are stored for each of the plurality of kinds of scatterers The method further comprising the steps of: At this time, reflection coefficients and diffraction coefficients corresponding to a plurality of kinds of scatterers can be selected and applied to the PO, IPO, and PTD approximation methods.

Measuring a scattered wave corresponding to the transmitted electromagnetic wave by transmitting a predetermined electromagnetic wave toward an arbitrary direction after storing the calculated radar reflection area with the incident electromagnetic wave and storing the scattered body identification reference information; And identifying the object by detecting the incident electromagnetic wave and the radar reflection area corresponding to the transmitted electromagnetic wave and the measured scattering wave among the stored scattering body identification reference information.

The method of measuring the radar reflection area using the radar reflection area measuring apparatus according to an embodiment of the present invention described above may also be implemented in the form of a recording medium including a program executable by a computer such as a program module executed by a computer . Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Radar reflection area measuring device
110: Memory
120: Processor
130: Transceiver

Claims (12)

In a radar cross section (RCS) measuring apparatus,
A memory for storing a radar reflection area measurement program; And
And a processor for executing a program stored in the memory,
The processor is configured to perform a radar reflection area measurement program on the incident electromagnetic wave using a predetermined physical optics (PO) approximation method and a physical theory of diffraction (PTD) Estimating a surface current induced in an illumination area and a corner area of a scatterer by a first surface current, estimating a first magnetic field value by a first surface current estimated through the PO approximation method, Estimating a third surface current induced in the shaded area of the scatterer based on a second magnetic field value due to the current and a third magnetic field value caused by the incident electromagnetic wave, The initial value of the surface current is determined by an iterative physical optics (IPO) approximation method based on a predetermined magnetic field integral equation (MFIE) The first scattered wave electric field and the second scattered wave electric field based on the first scattered wave electric field and the second surface electric current are summed to calculate a total scattered wave electric field, The radar reflection area measuring device stops the repeating procedure at the moment of divergence.
The method according to claim 1,
The processor comprising:
Wherein the IPO technique is a radar reflection area measuring device that processes the repetitive calculation using at least one of Jacobi, Gauss-Seidel, SOR, and Richardson iterative methods. .
3. The method of claim 2,
The processor comprising:
Detecting a size range corresponding to a size value according to a shape of the scatterer among a plurality of scatterer size ranges set in advance,
And at least one of the IPO approximation methods previously matched to the detected size range is selected to process the iterative calculation.
The method according to claim 1,
The processor comprising:
Calculating a radar reflection area of the scatterer based on the amplitude ratio of the total scattered wave electric field and the incident electromagnetic wave power,
Storing the calculated radar reflection area in the memory as scattering body identification reference information by matching with the incident electromagnetic wave,
Wherein a radar reflection area is calculated and stored by applying a parameter according to predetermined physical characteristics to a plurality of kinds of scatterers.
5. The method of claim 4,
In the memory,
A reflection coefficient and a diffraction coefficient set corresponding to physical characteristics of at least one of a size, a shape, and a medium are stored for each of the plurality of types of scatterers,
Wherein the processor selects the reflection coefficient and the diffraction coefficient corresponding to the scatterer, and applies the selected reflection coefficient and diffraction coefficient to the PO, IPO, and PTD approximation methods.
5. The method of claim 4,
Further comprising a transceiver for transmitting predetermined electromagnetic waves toward an arbitrary direction and measuring scattered waves corresponding to the transmitted electromagnetic waves,
The processor comprising:
And detects the incident electromagnetic wave and the radar reflection area corresponding to the transmitted electromagnetic wave and the measured scattered wave among the scatterer identification reference information stored in the memory to identify the object.
A method for measuring a radar cross-sectional area (RCS)
Using an incident electromagnetic wave using a predetermined physical optical (PO) approximation method and a physical theory of diffraction (PTD) approximation method, the incident light is guided to the illumination area and the corner area of the scatterer Estimating the first and second surface currents, respectively;
Based on the first magnetic field value by the first surface current estimated through the PO approximation method, the second magnetic field value by the second surface current estimated by the PTD approximation method, and the third magnetic field value by the incident electromagnetic wave, Estimating a third surface current induced in a shadow region of the scatterer;
The initial value of the surface current according to the sum of the first and third surface currents is subjected to iterative calculation processing through an iterative physical optics (IPO) approximation method based on a predetermined magnetic field integral equation (MFIE) 1) calculating a scattering wave field; And
And summing the first scattered wave electric field based on the first scattered wave electric field and the second scattered wave electric field based on the second surface electric current to calculate a total scattered wave electric field,
Wherein the instantaneous repeat procedure is terminated when the current magnitude diverges during the iterative calculation process according to the IPO.
8. The method of claim 7,
The IPO technique is a radar reflection area measurement method that processes the repetitive calculation using at least one of a Jacobi iteration method, a Gauss-Seidel iteration method, a Successive Over Relaxation (SOR) iteration method, and a Richardson iteration method .
9. The method of claim 8,
The step of calculating the reflected wave electric field by performing the repetitive calculation processing through the IPO approximation method includes:
Detecting a size range corresponding to a size value according to a shape of the scatterer among a plurality of scatterer size ranges set in advance; And
And selecting at least one of the IPO approximation methods previously matched to the detected size range to process the iterative calculation.
8. The method of claim 7,
After the step of calculating the total scattered wave field,
Calculating a radar reflection area of the scatterer based on the amplitude ratio of the total scattered wave electric field and the incident electromagnetic wave power; And
And storing the calculated radar reflection area as scattering body identification reference information by matching with the incident electromagnetic wave,
Wherein the radar reflection area is calculated and stored by applying a parameter according to predetermined physical characteristics to a plurality of kinds of scatterers.
11. The method of claim 10,
Before each step of estimating the first and second surface currents induced in the illumination region and the edge region,
And storing reflection coefficients and diffraction coefficients set corresponding to physical characteristics of at least one of size, shape and medium for each of the plurality of kinds of scatterers,
Wherein the reflection coefficient and the diffraction coefficient corresponding to each scattering body are selected and applied to the PO, IPO, and PTD approximation methods.
11. The method of claim 10,
After the calculated radar reflection area is matched with the incident electromagnetic wave and stored as scattering body identification reference information,
Transmitting predetermined electromagnetic waves toward an arbitrary direction and measuring scattered waves corresponding to the transmitted electromagnetic waves; And
Further comprising the step of identifying a target object by detecting the incident electromagnetic wave and the radar reflection area corresponding to the transmitted electromagnetic wave and the measured scattered wave among the stored scatterer identification reference information.

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