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Application method of chain relation in near-field to far-field transformation of near-field measurement system

A technology of measurement system and application method, which is applied in the field of near-field to far-field conversion of chain relation in the near-field measurement system, can solve problems such as complex deconvolution calculations, and achieve easy access to engineering applications, simple mathematical expressions, The effect of high measurement accuracy

Active Publication Date: 2021-01-12
BEIHANG UNIV
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Problems solved by technology

Deconvolution calculations are generally more complicated

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  • Application method of chain relation in near-field to far-field transformation of near-field measurement system
  • Application method of chain relation in near-field to far-field transformation of near-field measurement system
  • Application method of chain relation in near-field to far-field transformation of near-field measurement system

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Embodiment Construction

[0070] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0071] The current near-field RCS measurement is mainly to perform backward (single station) RCS measurement. For the backward RCS measurement, the transmitting antenna and the receiving antenna are at the same spatial point. If the transmitting and receiving antennas have the same pointing and pattern, the plane wave angle spectra of the two antennas are equal, that is, S T (θ,φ)=S R (θ,φ)=S(θ,φ). The shock response of the system is self-convolution S(θ,φ)*S(θ,φ). For the block diagram of self-convolution, see image 3 . image 3 E in i (x, y) is the complex amplitude on the plane perpendicular to the antenna passing through the center of rotation O of the target.

[0072] Will figure 2 and image 3 combined to get Figure 4 . Will Figure 4 The FFT and IFFT in cancel each other out, Figure 4 Simplified to Figure 5 . Figure 5 ...

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Abstract

The invention discloses an application method of a chain relation in the near-field to far-field transformation of a near-field measurement system. The invention changes the chain relation of NFFFT into a new expression form, and gives F 0 , F N and the relationship between the field distribution Ei on the plane perpendicular to the angular line of the radar irradiation line and the reflection line through the center of rotation of the target. The original relational expression is completely equivalent to the new relational expression, and the two belong to different expressions of the chain relational expression. But the new relation solves the original inverse convolution problem. It makes it easier for chain relations to enter engineering applications. Another content of the present invention is to propose an implementation method for near-field RCS measurement, including background cancellation, F N Calibration, NFFFT, NFFFT calibration, etc. Compared with the NFFFT method based on imaging concept and plane wave synthesis, the near-field RCS measurement technology and method of the present invention are relatively strict in theory, have simple mathematical expressions, clear physical concepts, and are easy to use in engineering.

Description

technical field [0001] The invention belongs to the field of low-observable technology and radar technology, in particular to an application method of a chain relation in the near-field to far-field transformation of a near-field measurement system. A new near-field measurement of scattering properties. Background technique [0002] Traditionally, RCS static measurement methods include external field and compact field. Field measurement occupies a large area, is costly, has many environmental interference sources, is affected by climate, and has low measurement efficiency. The quiet zone of the compact field is small in size and is mostly used for RCS testing of scaled models and components. [0003] In 2008, the Lockheed Martin company of the United States launched an RCS test system based on indoor point source near-field, which is used for the factory performance test of stealth aircraft. [0004] In the case that the far-field condition is not satisfied, the near-fiel...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01S7/41
CPCG01S7/411G01S7/418
Inventor 何国瑜李志平王正鹏武建华
Owner BEIHANG UNIV