A method of background extraction and cancellation in low detectable target rcs measurement

Abstract

The invention discloses a background extraction and offset processing method for RCS (Radar Cross Section) measurement of a low detectable target. The method can cover, but is not limited to, the existing operation including rectilinear translation of an auxiliary measurement carrier, azimuth rotation of an eccentric cylinder or rotation measurement of a dihedral angle reflector around a radar sight line. According to the method, a fixed background can be extracted by utilizing measurement data of various different auxiliary measurement bodies, thereby greatly expanding the application range of auxiliary background measurement, background extraction and offset technologies in the RCS measurement of the low detectable target. Particularly, when double-calibration bodies serve as the auxiliary measurement bodies, calibration measurement and auxiliary background extraction measurement can be simultaneously completed at a time; when targets self serve as the auxiliary measurement bodies, target measurement and auxiliary background extraction measurement are simultaneously completed at a time. According to the method, the measurement process and the workload are greatly simplified, and the problem of non-ideal background offset processing effect caused by the factors such as shifting of a measurement system is further solved.

Description

technical field [0001] The invention relates to the technical fields of communication and radar, in particular to a background extraction and offset processing method in radar cross section (RCS) measurement of low detectable targets. Background technique [0002] In order to discuss the measurement and calibration of the target wideband radar cross section (RCS) amplitude and phase, the target wideband complex scattering function is defined for: [0003] [0004] In the formula, E i (f) and E s (f) respectively represent the radar incident field (at the target) and the target scattered field (at the radar antenna); the relationship between it and the RCS is [0005] For target RCS broadband sweep measurements, there are: [0006] S T (f)=T(f)+B T (f)+N T (2) [0007] and [0008] S C (f)=C(f)+B C (f)+N C (3) [0009] In the formula, S T (f) and S C (f) respectively represent the echo signals received by the radar when measuring the target and measurin...

AI Technical Summary

Problems solved by technology

[0038] Disadvantages of prior art 1: The main disadvantage of using this auxiliary device is that it is necessary to design a special mechanism to drive the auxiliary measurement carrier to translate back and forth

[0041] Disadvantages of prior art 2: the technology of using eccentric cylinders for auxiliary measurement and background extraction avoids the requirement of translation of the carrier, but this technology also has the following obvious disadvantages:

Obviously, its extraction accuracy is difficult to guarantee

[0046] (2) Since the cross-polarization scattering component of the metal cylinder is zero, this device cannot be used for background auxiliary measurement and extraction under cross-polarization, so it cannot be used for polarization scattering matrix measurement applications

[0079] The main disadvantages of the prior art 3 are: (1) If simple average processing is used to extract the background level, it is generally required that the scattering of the dihedral corner reflector is high-frequency scattering, which requires the geometric size of the dihedral corner reflector to be relatively large. This makes its RCS level relatively high, and there is also the need to accurately extract a weak background signal that is several orders of magnitude smaller than the main echo from the measurement echo, and the extraction accuracy is difficult to guarantee; (2) If there is a large It is also necessary to design an auxiliary low-scattering cover to "hide" the rotating top, so as to prevent its strong scattering echo from affecting the scattering echo of the dihedral corner reflector, thereby affecting the background extraction process

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