CN106597380A - Inhomogeneous wave-based angle domain electromagnetic scattering characteristic synthesizing method - Google Patents

Abstract

The invention discloses an inhomogeneous wave-based angle domain electromagnetic scattering characteristic synthesizing method comprising the following steps: the maximum length L along an inhomogeneous wave observation direction is determined according to geometric profile parameters of an object, the maximum transverse dimension D of the object is determined according to a homogeneous plane wave observation angle change direction, an observation angle scope for synthesizable homogeneous plane wave scattering characteristics is determined according to the maximum length L of the object, a required minimum synthesis order N for inhomogeneous waves is determined according to the maximum transverse dimension D of the object and the observation angle scope [phi]max, an inhomogeneous wave scattering function of 0 to N orders at a central observation angle is calculated, and homogeneous plane waves RCS at other angles are synthesized via the calculated inhomogeneous wave scattering function of 0 to N orders. The inhomogeneous wave-based angle domain electromagnetic scattering characteristic synthesizing method disclosed in the invention can help solve a problem of object electromagnetic scattering characteristic angle domain change; the inhomogeneous wave-based angle domain electromagnetic scattering characteristic synthesizing method is advantageous in that scattering characteristics of the object at different observation angles can be compressed, and requirements for storage of object characteristic data can be greatly lowered.

Description

A kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave

Technical field

The present invention relates to electromagnetic characteristic of scattering analysis and feature extracting method, and in particular to one kind is based on non uniform wave Angle domain Electromagnetic Scattering Characteristics synthetic method.

Background technology

Ordinary circumstance, the scattering propertiess of target with observation angle quick change, at present, the target under different view angles Scattering propertiess typically adopt the pointwise method of sampling, and the Electromagnetic Characters of Target data volume of sampling is larger, causes to calculate or measure work Amount is huge, also larger to the storage pressure of target characteristic data.

The major issue that angle domain Electromagnetic Scattering Characteristics sampling quantity is that people are badly in need of solving how is reduced, is learned both at home and abroad Person has done substantial amounts of work, it is proposed that the model based on integral equation estimates that (abbreviation MBPE), Asymptotic Waveform estimate (referred to as ) and the method such as Mei Li AWE.

Representative references are as follows：

Zhang Xiaoyan etc. is published in for 2015《Beijing Institute of Technology's journal》On non-patent literature " target back scattering RCS Quick calculating based on MBPE uniform samplings " discloses target radar scattering cross-section (Radar Cross-Section, abbreviation RCS sky), the MBPE uniform sampling schemes in two domains of frequency, in spatial domain, propose based on the wide angle of spherical wave angular spectrum space development Sampling plan, proposes the sampling experience under first training different incidence angles in low-frequency range, and MBPE is then carried out on high band again Interpolation calculation.Numerical result shows, in spatial domain, the sampling number of MBPE is typically only the 1/2 of Fast Multiple Method sampling number, And reduce with the diminution of interpolation angular range.The method is based on spherical wave angular spectrum, is not directed to the application of non uniform wave.

Chen Wenfeng etc. is published in for 2014《Microwave journal》On non-patent literature " a kind of scattering of radar target width angular domain Rapid analysis method " discloses a kind of NEW ADAPTIVE integration method and quickly analyzes the scattering of target spatial domain with reference to prunus mume (sieb.) sieb.et zucc. profit approximation technique The method of characteristic, the method solves projection coefficient using Gauss interpolation operator, it is easier to programming realization, for the scattering of wide angular domain is asked Topic, using prunus mume (sieb.) sieb.et zucc. profit approximation computation target under other angles on RCS, in the case where low error is ensured, the method is in internal memory Need to be had clear improvement on the read group total time, the method is approached based on prunus mume (sieb.) sieb.et zucc. profit, is also not directed to the application of non uniform wave.

Korea etc. are published in for 2009《Microwave journal》On non-patent literature " the quick analyzing three-dimensionals of AMCBFM-MBPE The broadband and wideangle scattering propertiess of target " are disclosed a kind of adaptive correction Characteristic Basis Function Method (AM-CBFM) and are joined based on model Number estimates the technology of (MBPE) and combines to construct a kind of hybrid algorithm of quick analyzing three-dimensional objective body broadband and wideangle electromagnetic property, than The traditional method of node-by-node algorithm objective body electromagnetic property considerably reduces the number of sampled point, but is not directed to answering for non uniform wave With.

Because patent of the present invention is based on non uniform wave, the concept of non uniform wave and its scattering function is following present.

Non uniform wave refers to field intensity electromagnetic wave pockety on wavefront front.For ease of analysis, people can enter to it The power series expansion of row one-dimensional square, different power series represent the non uniform wave of not same order.Without loss of generality, it is assumed that non uniform wave The direction of propagation is coordinate system-X-direction, and E field polarization direction is set to coordinate system+Z-direction, and it is true that Y direction presses right-hand rule It is fixed, and assume field intensity change along Y direction, then field strength distribution of the m ranks non uniform wave on wavefront front can be written as

E (y)=E_my^m (1)

In formula, E_mFor the coefficient of m rank non uniform waves field intensity change.

Scattering to One-dimensional Inhomogeneous ripple, the corresponding non uniform wave scattering function of definable

In formula, R_rFor distance between observation station and zero, E_sTo scatter field distribution at observation station；e_rFor unit receiving pole Change vector；It is the n rank derivations along Y direction, wherein 0 rank derivation is original function,Represent and dissipate Penetrate a variation coefficient for n ranks；E_mChange for non uniform wave incident field strength in target area, m is incident non uniform wave exponent number. Leading reference is as follows：

Liang Zichang etc. is published in for 2013《Guidance and fuse》On non-patent literature " the linear non-homogeneous electricity of corner reflector Magnetic wave scattering propertiess " disclose the calculating process of typical target non uniform wave scattering propertiess, are not directed to angle domain electromagnetic scattering special The synthesis of property.

Ten thousand state guests etc. are published in for 2008《Electric wave science journal》On non-patent literature " with cover antenna scattering calculate son Plane wave technology " discloses equivalent and Gordon formula the electromagnetic current radiation integrating meter of sub- plane wave based on inhomogeneous electromagnetic wave The method for calculating antenna house scattering, is not directed to the synthesis of angle domain Electromagnetic Scattering Characteristics.

Liu Fu equalitys are published in for 2006《Chinese Journal of Geophysics》On non-patent literature " inhomogeneous electromagnetic wave is in conductive matchmaker The lateral shift of matter interface reflection " discloses lateral shift computational methods of the inhomogeneous electromagnetic wave in interface of conductive media, does not relate to And the synthesis of angle domain Electromagnetic Scattering Characteristics.

The content of the invention

It is an object of the invention to provide a kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave, solves Electromagnetic characteristic of scattering angle domain transformation problem, realizes being compressed the scattering propertiess under target difference observation angle, greatly Width reduces the purpose of the memory requirement of target characteristic data.

To achieve the above object, the present invention provides a kind of angle domain Electromagnetic Scattering Characteristics based on non uniform wave and synthesizes Method, comprises the steps of：

Step S1, according to target geometric shape parameter determination target along non uniform wave observed direction greatest length L；Together When, according to uniform plane wave view angleAngle change direction determine maximum transverse size D of target；

Step S2, according to target maximum length L the view angle of corresponding maximum is determinedAnd by the maximum view angleTo determine the uniform plane wave scattering propertiess observation angle scope that can synthesize；

Step S3, according to target maximum lateral dimension D and observation angle scopeDetermine the minimum synthesis rank of non uniform wave Number N；

Step S4, by receiving any one central observation angle in the range of scattered field derived function observation angleUnder, The non uniform wave scattering function of 0～N ranks of target；

Step S5, according to 0～N ranks non uniform wave scattering function central observation angle is synthesizedNearby in set point its Uniform plane wave RCS under his angle.

Preferably, in step S2, the uniform plane wave scattering propertiess observation angle scope that synthesizes is

The maximum view angleFor

In formula, k=2 π f/c are electromagnetic wave wave number, and f is wave frequency, and c is propagation velocity of electromagnetic wave.

Preferably, in step S2, the maximum effective angle of the synthesis uniform plane wave scattering propertiessMeetCondition, wherein k be electromagnetic wave wave number.

Preferably, in step S3, the minimum synthesis exponent number N of the non uniform wave take target lateral electric size kD with most Big view angleMore than one times of sinusoidal product, i.e.,Wherein k is electromagnetic wave wave number, and D is that target maximum is horizontal To size.

Preferably, in step S4, the reception scattered field is obtained or profit by different electromagnetic calculation simulation calculations Obtained with the measurement of electromagnetic scattering measuring system.

Preferably, in step S5, using any central observation angleUnder target the non-homogeneous wave dispersion of 0～N ranks Function is penetrated, by weighting composite calulation the central observation angle is obtainedNeighbouring certain angle scopeIt is interior uniform Plane wave RCS.

Preferably, in step S5, the composite calulation formula of the uniform plane wave RCS is as follows：

a₀=1

In formula,For the angle of incidence of uniform plane wave；

Compared with prior art, the invention has the beneficial effects as follows：

The present invention is realized under other observation angles using the high-order Inhomogeneous Plane Wave scattering propertiess of an observation angle The synthesis of uniform plane wave scattering propertiess.On the one hand, using the present invention, extrapolated using the target scattering characteristics under a view angle Target scattering characteristics under other observation angles, so as to meet target difference angle under scattering propertiess calculate or test volume need Ask；On the other hand, using the present invention can be to target under different observation angles scattering propertiess be compressed, it is right to significantly reduce The memory requirement of target scattering characteristics data.

Description of the drawings

Fig. 1 is flow chart of the present invention based on the angle domain Electromagnetic Scattering Characteristics synthetic method of non uniform wave；

Fig. 2 is calculating target of the present invention based on the embodiment of the angle domain Electromagnetic Scattering Characteristics synthetic method of non uniform wave The schematic diagram of non uniform wave scattering function；

Fig. 3 is that not same order of the present invention based on the embodiment of the angle domain Electromagnetic Scattering Characteristics synthetic method of non uniform wave is non- Homogeneous wave scattering function change curve；

Fig. 4 is non uniform wave of the present invention based on the embodiment of the angle domain Electromagnetic Scattering Characteristics synthetic method of non uniform wave The angle domain scattering characteristic curve comparison diagram that method of deploying is obtained.

Specific embodiment

Below in conjunction with accompanying drawing, by describing a preferably specific embodiment in detail, the present invention is further elaborated.

With reference to shown in Fig. 1～Fig. 4, in the present embodiment, the angle domain Electromagnetic Scattering Characteristics synthesis side based on non uniform wave Method is comprised the following steps：

Step S1, according to target geometric shape parameter determination target along non uniform wave observed direction greatest length L；Together When, maximum transverse size D of target is determined according to uniform plane wave observation angle change direction.

As shown in Fig. 2 target is the assembly of metal ball and metal plate, and wherein metal bulb diameter 0.2m, sphere centre coordinate For (0, -0.2m, 0)；The flat board length of side be 0.1m, centre coordinate for (0,0.2m, 0)；Inhomogeneous electromagnetic wave observed direction is x-axis side To target maximum length L=0.2m in this direction, uniform plane wave observation angle changes in the horizontal direction, and view angle here is Refer to that uniform plane wave observed direction is designated as with x-axis angleView angleChange direction is Y direction, corresponding target maximum Lateral dimension D=0.55m.

Step S2, the uniform plane wave scattering propertiess observation angle scope that can synthesize is determined according to target maximum length L, i.e.,

In formula, k=2 π f/c are electromagnetic wave wave number, and f is wave frequency, and 8GHz is taken as in the present embodiment, and c is electromagnetism Velocity of wave propagation, is taken as in the present embodiment 3 × 10⁸m/s.Substitute into and be obtained after calculating

Step S3, according to target maximum lateral dimension D and observation angle scopeIt is determined that desired non uniform wave is minimum Synthesis exponent number N；Estimation equation is as follows：

N is taken as 18 in the present embodiment.

Step S4, calculates central observation angleThe non uniform wave scattering function of lower 0～N ranks；

In the present embodiment, distance is set to R between observation station and coordinate origin_r=2km, using physical optical method gold is calculated Category ball and scattered field of the metal plate assembly target near observation station；Further according to the definition of non uniform wave scattering function, pass through Derived function obtains the non uniform wave scattered field variation coefficient of 0～18 rank, and then calculates non uniform wave scattering function, and its result is such as Shown in Fig. 3.

Step S5, using the 0～N rank non uniform wave scattering functions for calculating uniform plane wave RCS under other angles is synthesized, its Middle weight coefficient is related to view angle；In the present embodiment, the composite calulation formula of uniform plane wave RCS is as follows：

a₀=1 (8)

In formula,For the angle of incidence of uniform plane wave；

As shown in figure 4, in the present embodiment, according to formula (6)～(10), using non uniform wave scattering function composite calulation Uniform plane wave RCS results are coincide preferably with the uniform plane wave RCS results for directly calculating, and demonstrate the effectiveness of this method.

In sum, the present invention realizes other sights using the high-order Inhomogeneous Plane Wave scattering propertiess of an observation angle The synthesis of uniform plane wave scattering propertiess under measuring angle.On the one hand, using the present invention, using the target scattering under a view angle The target scattering characteristics that characteristic is extrapolated under other observation angles, so as to meet target difference angle under scattering propertiess calculate or survey The demand of examination amount；On the other hand, using the present invention can be to target under different observation angles scattering propertiess be compressed, significantly Reduce the memory requirement to target scattering characteristics data.

Although present disclosure has been made to be discussed in detail by above preferred embodiment, but it should be appreciated that above-mentioned Description is not considered as limitation of the present invention.After those skilled in the art have read the above, for the present invention's Various modifications and substitutions all will be apparent.Therefore, protection scope of the present invention should be limited to the appended claims.

Claims (7)

1. a kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave, it is characterised in that comprise the steps of：

Step S1, according to target geometric shape parameter determination target along non uniform wave observed direction greatest length L；Meanwhile, root Determine maximum transverse size D of target according to the angle change direction of uniform plane wave view angle；

Step S2, according to the target maximum length L view angle of corresponding maximum is determinedAnd by the maximum view angleTo determine the uniform plane wave scattering propertiess observation angle scope that can synthesize；

Step S3, according to the target maximum lateral dimension D and the observation angle scope the minimum synthesis of non uniform wave is determined Exponent number N；

Step S4, by receiving any one central observation angle in the range of scattered field derived function observation angleUnder, target 0～N ranks non uniform wave scattering function；

Step S5, according to 0～N ranks non uniform wave scattering function central observation angle is synthesizedOther angles in neighbouring set point The uniform plane wave RCS of degree.

2. as claimed in claim 1 a kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave, it is characterised in that In step S2, the uniform plane wave scattering propertiess observation angle scope that synthesizes is

The maximum view angleFor

In formula, k=2 π f/c are electromagnetic wave wave number, and f is wave frequency, and c is propagation velocity of electromagnetic wave.

3. a kind of as claimed in claim 1 or 2 angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave, its feature exists In, in step S2, the maximum view angle of the synthesis uniform plane wave scattering propertiessMeetCondition, wherein k be electromagnetic wave wave number.

4. as claimed in claim 1 a kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave, it is characterised in that In step S3, the minimum synthesis exponent number N of the non uniform wave takes target lateral electrically large sizes kD with maximum view angleJust More than one times of string product, i.e.,Wherein k is electromagnetic wave wave number.

5. as claimed in claim 1 a kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave, it is characterised in that In step S4, the reception scattered field is obtained by different electromagnetic calculation simulation calculations or is using electromagnetic scattering measurement Unified test amount is obtained.

6. as claimed in claim 1 a kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave, it is characterised in that In step S5, using any central observation angleUnder target 0～N rank non uniform wave scattering functions, by weighting Composite calulation obtains the central observation angleNeighbouring certain angle scopeInterior uniform plane wave RCS.

7. a kind of angle domain Electromagnetic Scattering Characteristics synthetic method based on non uniform wave as described in claim 1 or 6, its feature exists In in step S5, the composite calulation formula of the uniform plane wave RCS is as follows：

a₀=1

$a_{2n}=b^{2n}\&lsqb;\frac{1}{n!n!}+\underset{i=i_0}{\overset{n-1}{\&Sigma;}}\frac{2}{i!(2n-i)!}\&rsqb;,i_0=\left\{\begin{array}{cc}2n-N,& n\&GreaterEqual;N/2\\ 0,& n<N/2\end{array}\right.$

$a_{2n+1}=b^{2n+1}\&lsqb;\underset{i=i_0}{\overset{n}{\&Sigma;}}\frac{2}{i!(2n+1-i)!}\&rsqb;,i_0=\left\{\begin{array}{cc}2n+1-N,& n\&GreaterEqual;N/2\\ 0,& n<N/2\end{array}\right.$

In formula,For the angle of incidence of uniform plane wave；