Target scattering characteristic data mode conversion method and device based on transfer matrix

Abstract

The present invention relates to a method and device for converting target scattering characteristic data mode based on a transfer matrix, the method comprising the following steps: gridding a target area; constructing an observation matrix A1 of a first near-field test mode, constructing an observation matrix A2 of a second near-field test mode, constructing a transfer matrix A based on the observation matrix A1 and the observation matrix A2; and mapping target scattering characteristic data of the first near-field test mode to target scattering characteristic data of the second near-field test mode is achieved through the transfer matrix A. The method of the present invention establishes a mapping relationship of scattering characteristic data between different near-field measurement modes of the same target with the help of the concept of a transfer matrix, so as to achieve evaluation and fusion processing of test data under different near-field measurement modes.

Description

Technical Field

[0001] The present invention relates to the technical field of RCS testing and data processing, and in particular to a method and device for converting data in different measurement modes under near-field conditions. Background Art

[0002] The definition of target RCS (radar cross section) is a far-field concept, which requires that the incident wave illuminating the target and the scattered wave reaching the receiving antenna are both plane waves. But a truly ideal plane wave does not exist. At present, in engineering, outdoor field RCS testing generally adopts a far-field approach, that is, the distance between the target and the measurement system is far enough that the incident wave and the scattered wave are approximately plane waves; indoors, equipment such as parabolic reflectors are used to convert the spherical waves radiated by the feed source into plane waves within a certain area. When the test conditions are limited and an approximate plane wave cannot be achieved, researchers use a near-far field transformation measurement method to extract the target's far-field scattering information from the near-field scattered echo, and then obtain the RCS.

[0003] Common near-field measurement methods include linear scanning mode and circular scanning mode. The circular scanning mode is more common in laboratory environments, while the linear scanning mode is more common in field test conditions. The circular scanning mode generally uses equal angle intervals for data collection, while the linear scanning mode generally uses equal distance intervals for data collection. Therefore, the target scattering characteristic data obtained by the two scanning modes cannot be directly compared or fused.

[0004] In view of the above shortcomings, it is necessary to provide a method and device for converting target scattering characteristic data in a linear scanning mode and target scattering characteristic data in a circular scanning mode. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the target scattering characteristic data obtained from tests in different scanning modes cannot be directly compared or fused. In view of the defects in the prior art, based on the principle of invariance of scattering distribution function, a method and device for target scattering characteristic data mode conversion based on a transfer matrix is ​​provided to realize a data conversion method between different near-field measurement modes, so as to solve the problems of evaluation, comparison and processing of target scattering characteristic data obtained under different near-field test modes in actual engineering tests.

[0006] In order to solve the above technical problems, the present invention provides a method for converting a target scattering characteristic data pattern based on a transfer matrix, comprising the following steps: gridding the target area; constructing an observation matrix A1 of a first near-field test mode, wherein the observation matrix A1 realizes the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering center; constructing an observation matrix A2 of a second near-field test mode, wherein the observation matrix A2 realizes the mapping of the target scattering center to the target scattering characteristic data of the second near-field test mode; constructing a transfer matrix A based on the observation matrix A1 and the observation matrix A2; and realizing the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A.

[0007] Preferably, in the step of gridding the target area, the gridding area is centered on the center of the target area, and an area with a horizontal length and a vertical length of D is constructed, wherein the number of horizontal gridding points Nx and the number of vertical gridding points Ny should satisfy:

[0008]

[0009] Wherein, Θ is the aperture angle of the target scattering characteristic data of the first near-field test mode relative to the target, f is the highest frequency of the test data, B is the bandwidth corresponding to the test data, and c0 represents the speed of light in vacuum.

[0010] Preferably, in the step of constructing the measurement matrix A1 of the first near-field test mode, the measurement matrix A1 is expressed as:

[0011]

[0012] in represents the (m,n)th element of the observation matrix A1; R m,n Indicates the distance from the mth point in the target area to the test antenna in the nth test state, with the test antenna position as the origin of the coordinate system; x m,n With y m,n represents the coordinates of the mth point; f n is the frequency corresponding to the nth test state.

[0013] Preferably, in the step of constructing the measurement matrix A2 of the second near-field test mode, the measurement matrix A2 is expressed as:

[0014]

[0015] in represents the (k, j)th element of the observation matrix A2; R k,,j It represents the distance from the jth point in the target area to the test antenna under the kth test state, with the test antenna position as the origin of the coordinate system; x k,j With y k,jrepresents the coordinates of the jth point; f k and is the frequency corresponding to the kth test state.

[0016] Preferably, in the step of constructing a transfer matrix A based on the measurement matrix A1 and the measurement matrix A2, the constructed transfer matrix A can be expressed as:

[0017] A=A2·A1.

[0018] Preferably, in the step of mapping the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode by transferring the matrix A, S2=A·S1; wherein S1 is the target scattering characteristic data of the first near-field test mode, and S2 is the target scattering characteristic data of the second near-field test mode.

[0019] Preferably, the first near-field test mode is a linear scanning mode, and the second near-field test mode is a circular scanning mode; or the first near-field test mode is a circular scanning mode, and the second near-field test mode is a linear scanning mode.

[0020] The present invention also provides a target scattering characteristic data pattern conversion device based on a transfer matrix, comprising: a grid processing module, the grid processing module is used to perform grid processing on the target area; a first observation matrix construction module, the first observation matrix construction module is used to construct an observation matrix A1 of a first near-field test mode, the observation matrix A1 realizes the mapping of target scattering characteristic data of the first near-field test mode to the target scattering center; a second observation matrix construction module, the second observation matrix construction module is used to construct an observation matrix A2 of a second near-field test mode, the observation matrix A2 realizes the mapping of the target scattering center to the target scattering characteristic data of the second near-field test mode; a transfer matrix construction module, the transfer matrix construction module is used to construct a transfer matrix A based on the observation matrix A1 and the observation matrix A2; and a calculation module, the calculation module is used to realize the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A.

[0021] Preferably, during the process of the grid processing module performing grid processing on the target area, the grid area is centered on the center of the target area, and a region with a horizontal length and a vertical length of D is constructed, wherein the horizontal grid point number Nx and the vertical grid point number Ny should satisfy:

[0022]

[0023] Wherein, Θ is the aperture angle of the target scattering characteristic data of the first near-field test mode relative to the target, f is the highest frequency of the test data, B is the bandwidth corresponding to the test data, and c0 represents the speed of light in vacuum.

[0024] Preferably, in the process of constructing the measurement matrix A1 of the first near-field test mode by the first measurement matrix construction module, the measurement matrix A1 is expressed as:

[0025]

[0026] in represents the (m,n)th element of the observation matrix A1; R m,n Indicates the distance from the mth point in the target area to the test antenna in the nth test state, with the test antenna position as the origin of the coordinate system; x m,n With y m,n represents the coordinates of the mth point; f n is the frequency corresponding to the nth test state;

[0027] In the process of constructing the measurement matrix A2 of the second near-field test mode by the second measurement matrix construction module, the measurement matrix A2 is expressed as:

[0028]

[0029] in represents the (k, j)th element of the observation matrix A2; R k,,j It represents the distance from the jth point in the target area to the test antenna under the kth test state, with the test antenna position as the origin of the coordinate system; x k,j With y k,j represents the coordinates of the jth point; f k and is the frequency corresponding to the kth test state.

[0030] The implementation of the target scattering characteristic data mode conversion method and device based on the transfer matrix of the present invention has the following beneficial effects: based on the principle of invariance of the scattering distribution function, a data conversion method and device between different near-field measurement modes are provided to solve the problem of evaluating, comparing and processing the target scattering characteristic data obtained under different near-field test modes in actual engineering tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of a method for converting target scattering characteristic data mode based on a transfer matrix according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, the target scattering characteristic data mode conversion method based on the transfer matrix provided by an embodiment of the present invention includes the following steps: step S01: gridding the target area; step S02: constructing an observation matrix A1 of the first near-field test mode, the observation matrix A1 realizes the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering center; step S03: constructing an observation matrix A2 of the second near-field test mode, the observation matrix A2 realizes the mapping of the target scattering center to the target scattering characteristic data of the second near-field test mode; step S04: constructing a transfer matrix A based on the observation matrix A1 and the observation matrix A2; step S05: realizing the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A.

[0034] The present invention relates to the field of RCS testing and data processing technology, in particular to a method for converting electromagnetic scattering test data of targets in different measurement modes (linear scanning, circular scanning) under near-field conditions. According to test scene parameters, radar system parameters and φ, an observation matrix A1 under the first near-field test mode is constructed; an observation matrix A2 under the second near-field test mode is constructed; a transfer matrix A is constructed using A1 and A2, and A is multiplied by the characteristic data of the target in the first near-field test mode to obtain the characteristic data of the target under the first near-field test mode. With the help of the concept of transfer matrix, the present invention directly establishes a mapping relationship of scattering characteristic data between different near-field measurement modes of the same target, so as to realize the evaluation and fusion processing of near-field test data in different modes. The method is based on the premise that the distribution of target scattering centers remains unchanged under different near-field test modes; the method uses the concept of scattering centers, but does not require imaging processing during the processing process. The function of mutual conversion between scattering characteristic data of targets in different near-field modes can be realized in the form of an observation matrix.

[0035] In the target scattering characteristic data mode conversion method based on the transfer matrix provided by the embodiment of the present invention, in the step of gridding the target area, the gridded area is centered on the center of the target area, and a region with a horizontal length and a vertical length of D is constructed, wherein the horizontal gridding point number Nx and the vertical gridding point number Ny should satisfy:

[0036]

[0037] Wherein, Θ is the aperture angle of the target scattering characteristic data of the first near-field test mode relative to the target, f is the highest frequency of the test data, B is the bandwidth corresponding to the test data, and c0 represents the speed of light in vacuum.

[0038] In the target scattering characteristic data mode conversion method based on the transfer matrix provided by the embodiment of the present invention, in the step of constructing the measurement matrix A1 of the first near-field test mode, the measurement matrix A1 is expressed as:

[0039]

[0040] in represents the (m,n)th element of the observation matrix A1; R m,n Indicates the distance from the mth point in the target area to the test antenna in the nth test state, with the test antenna position as the origin of the coordinate system; x m,n With y m,n represents the coordinates of the mth point; f n is the frequency corresponding to the nth test state.

[0041] In the target scattering characteristic data mode conversion method based on the transfer matrix provided by the embodiment of the present invention, in the step of constructing the measurement matrix A2 of the second near-field test mode, the measurement matrix A2 is expressed as:

[0042]

[0043] in represents the (k, j)th element of the observation matrix A2; R k,,j It represents the distance from the jth point in the target area to the test antenna under the kth test state, with the test antenna position as the origin of the coordinate system; x k,j With y k,j represents the coordinates of the jth point; f k and is the frequency corresponding to the kth test state.

[0044] In the target scattering characteristic data mode conversion method based on the transfer matrix provided by the embodiment of the present invention, in the step of constructing the transfer matrix A based on the measurement matrix A1 and the measurement matrix A2, the constructed transfer matrix A can be expressed as:

[0045] A=A2·A1.

[0046] In the target scattering characteristic data mode conversion method based on the transfer matrix provided in an embodiment of the present invention, in the step of mapping the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A, S2=A·S1; wherein S1 is the target scattering characteristic data of the first near-field test mode, and S2 is the target scattering characteristic data of the second near-field test mode.

[0047] In the target scattering characteristic data mode conversion method based on the transfer matrix provided in an embodiment of the present invention, the first near-field test mode is a linear scanning mode, and the second near-field test mode is a circular scanning mode; or the first near-field test mode is a circular scanning mode, and the second near-field test mode is a linear scanning mode.

[0048] An embodiment of the present invention also provides a device for converting a target scattering characteristic data pattern based on a transfer matrix, the device comprising: a grid processing module, the grid processing module is used to perform grid processing on the target area; a first observation matrix construction module, the first observation matrix construction module is used to construct an observation matrix A1 of a first near-field test mode, the observation matrix A1 realizes the mapping of target scattering characteristic data of the first near-field test mode to the target scattering center; a second observation matrix construction module, the second observation matrix construction module is used to construct an observation matrix A2 of a second near-field test mode, the observation matrix A2 realizes the mapping of the target scattering center to the target scattering characteristic data of the second near-field test mode; a transfer matrix construction module, the transfer matrix construction module is used to construct a transfer matrix A based on the observation matrix A1 and the observation matrix A2; and a calculation module, the calculation module is used to realize the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A.

[0049] In the target scattering characteristic data mode conversion device based on the transfer matrix provided by the embodiment of the present invention, during the process of the grid processing module performing grid processing on the target area, the grid area is centered on the center of the target area, and a region with a horizontal length and a vertical length of D is constructed, wherein the horizontal grid point number Nx and the vertical grid point number Ny should satisfy:

[0050]

[0051] Wherein, Θ is the aperture angle of the target scattering characteristic data of the first near-field test mode relative to the target, f is the highest frequency of the test data, B is the bandwidth corresponding to the test data, and c0 represents the speed of light in vacuum.

[0052] In the target scattering characteristic data mode conversion device based on the transfer matrix provided by the embodiment of the present invention, during the process in which the first measurement matrix construction module constructs the measurement matrix A1 of the first near-field test mode, the measurement matrix A1 is expressed as:

[0053]

[0054] in represents the (m,n)th element of the observation matrix A1; R m,n Indicates the distance from the mth point in the target area to the test antenna in the nth test state, with the test antenna position as the origin of the coordinate system; x m,n With y m,nrepresents the coordinates of the mth point; f n is the frequency corresponding to the nth test state;

[0055] In the process of constructing the measurement matrix A2 of the second near-field test mode by the second measurement matrix construction module, the measurement matrix A2 is expressed as:

[0056]

[0057] in represents the (k, j)th element of the observation matrix A2; R k,,j It represents the distance from the jth point in the target area to the test antenna under the kth test state, with the test antenna position as the origin of the coordinate system; x k,j With y k,j represents the coordinates of the jth point; f k and is the frequency corresponding to the kth test state.

[0058] In the target scattering characteristic data mode conversion device based on the transfer matrix provided by the embodiment of the present invention, during the process of constructing the transfer matrix A by the transfer matrix construction module, the constructed transfer matrix A can be expressed as:

[0059] A=A2·A1.

[0060] In the target scattering characteristic data mode conversion device based on transfer matrix provided in an embodiment of the present invention, the calculation module realizes the mapping of target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A, S2=A·S1; wherein S1 is the target scattering characteristic data of the first near-field test mode, and S2 is the target scattering characteristic data of the second near-field test mode.

[0061] In the target scattering characteristic data mode conversion device based on the transfer matrix provided by an embodiment of the present invention, the first near-field test mode is a linear scanning mode, and the second near-field test mode is a circular scanning mode; or the first near-field test mode is a circular scanning mode, and the second near-field test mode is a linear scanning mode.

[0062] In summary, the implementation of the target scattering characteristic data mode conversion method and device based on the transfer matrix of the present invention has the following beneficial effects: based on the principle of invariance of the scattering distribution function, a data conversion method and device between different near-field measurement modes are provided to solve the problem of evaluating, comparing and processing the target scattering characteristic data obtained under different near-field test modes in actual engineering tests.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for converting target scattering characteristic data mode based on transfer matrix, characterized in that: The steps include: Gridding the target area; Constructing an observation matrix A1 of a first near-field test mode, wherein the observation matrix A1 realizes mapping of target scattering characteristic data of the first near-field test mode to target scattering centers; Constructing an observation matrix A2 of a second near-field test mode, wherein the observation matrix A2 realizes mapping of a target scattering center to target scattering characteristic data of the second near-field test mode; Constructing a transfer matrix A based on the measurement matrix A1 and the measurement matrix A2; The transfer matrix A is used to map the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode.

2. The target scattering characteristic data mode conversion method based on transfer matrix according to claim 1 is characterized in that: In the step of gridding the target area, the gridding area is centered on the center of the target area, and a region with a horizontal length and a vertical length of D is constructed, wherein the number of horizontal grid points Nx and the number of vertical grid points Ny should satisfy: Wherein, Θ is the aperture angle of the target scattering characteristic data of the first near-field test mode relative to the target, f is the highest frequency of the test data, B is the bandwidth corresponding to the test data, and c0 represents the speed of light in vacuum.

3. The target scattering characteristic data mode conversion method based on transfer matrix according to claim 1 is characterized in that: In the step of constructing the measurement matrix A1 of the first near-field test mode, the measurement matrix A1 is expressed as: in represents the (m,n)th element of the observation matrix A1; R m,n Indicates the distance from the mth point in the target area to the test antenna in the nth test state, with the test antenna position as the origin of the coordinate system; x m,n With y m,n represents the coordinates of the mth point; f n is the frequency corresponding to the nth test state.

4. The target scattering characteristic data mode conversion method based on transfer matrix according to claim 1 is characterized in that: In the step of constructing the measurement matrix A2 of the second near-field test mode, the measurement matrix A2 is expressed as: in represents the (k, j)th element of the observation matrix A2; R k,j It represents the distance from the jth point in the target area to the test antenna under the kth test state, with the test antenna position as the origin of the coordinate system; x k,j With y k,j represents the coordinates of the jth point; f k and is the frequency corresponding to the kth test state.

5. The target scattering characteristic data mode conversion method based on transfer matrix according to claim 1 is characterized in that: In the step of constructing the transfer matrix A based on the measurement matrix A1 and the measurement matrix A2, the constructed transfer matrix A can be expressed as: A=A2·A1.

6. The target scattering characteristic data mode conversion method based on transfer matrix according to any one of claims 1 to 5, characterized in that: In the step of implementing the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A, S2=A·S1; Among them, S1 is the target scattering characteristic data of the first near-field test mode, and S2 is the target scattering characteristic data of the second near-field test mode.

7. The target scattering characteristic data mode conversion method based on transfer matrix according to claim 6 is characterized in that: The first near-field test mode is a linear scanning mode, and the second near-field test mode is a circular scanning mode; or the first near-field test mode is a circular scanning mode, and the second near-field test mode is a linear scanning mode.

8. A target scattering characteristic data mode conversion device based on a transfer matrix, characterized in that: include: A grid processing module, wherein the grid processing module is used to perform grid processing on the target area; A first measurement matrix construction module, the first measurement matrix construction module is used to construct an measurement matrix A1 of a first near-field test mode, the measurement matrix A1 realizes mapping of target scattering characteristic data of the first near-field test mode to target scattering centers; A second measurement matrix construction module, the second measurement matrix construction module is used to construct an measurement matrix A2 of a second near-field test mode, the measurement matrix A2 realizes mapping of a target scattering center to target scattering characteristic data of the second near-field test mode; A transfer matrix construction module, wherein the transfer matrix construction module is used to construct a transfer matrix A based on the measurement matrix A1 and the measurement matrix A2; A calculation module is used to realize the mapping of the target scattering characteristic data of the first near-field test mode to the target scattering characteristic data of the second near-field test mode through the transfer matrix A.

9. The target scattering characteristic data mode conversion device based on transfer matrix according to claim 8, characterized in that: During the process of the grid processing module performing grid processing on the target area, the grid area is centered on the center of the target area, and a region with a horizontal length and a vertical length of D is constructed, wherein the horizontal grid point number Nx and the vertical grid point number Ny should satisfy: Wherein, Θ is the aperture angle of the target scattering characteristic data of the first near-field test mode relative to the target, f is the highest frequency of the test data, B is the bandwidth corresponding to the test data, and c0 represents the speed of light in vacuum.

10. The target scattering characteristic data mode conversion device based on transfer matrix according to claim 8 or 9, characterized in that: In the process of constructing the measurement matrix A1 of the first near-field test mode by the first measurement matrix construction module, the measurement matrix A1 is expressed as: in represents the (m,n)th element of the observation matrix A1; R m,n Indicates the distance from the mth point in the target area to the test antenna in the nth test state, with the test antenna position as the origin of the coordinate system; x m,n With y m,n represents the coordinates of the mth point; f n is the frequency corresponding to the nth test state; In the process of constructing the measurement matrix A2 of the second near-field test mode by the second measurement matrix construction module, the measurement matrix A2 is expressed as: in represents the (k, j)th element of the observation matrix A2; R k,j It represents the distance from the jth point in the target area to the test antenna under the kth test state, with the test antenna position as the origin of the coordinate system; x k,j With y k,j represents the coordinates of the jth point; f k and is the frequency corresponding to the kth test state.

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