A 3D imaging method for terahertz radar targets based on dual-frequency interference

Abstract

The present invention provides a double-frequency interference-based THz radar target three-dimensional imaging method, wherein the coordinates of a target in three dimensions of distance, azimuth and pitch can be obtained. Meanwhile, the azimuth-pitch 2D image of the target, including the 2D coordinates of the target and the 2D scattering intensity distribution of the target, is obtained through the azimuth-pitch imaging process. The distance-dimension coordinates of the target are obtained through the interference treatment on two azimuth-pitch images of two adjacent frequency points. During the double-frequency interference-based azimuth-pitch imaging process, the small-angle two-dimensional rotation of a target is utilized to obtain the high resolution in the dimensions of both azimuth and pitch. Meanwhile, the double-frequency imaging mode avoids the usage of wideband signals during the 3D imaging process and the non-linear influence of signals. The above method is simple in imaging process and high in efficiency, which realizes the 3D imaging of a radar target.

Description

technical field [0001] The invention belongs to the technical field of radar imaging, in particular to an azimuth-elevation dual-frequency interference imaging method related to three-dimensional imaging of a terahertz radar target. Background technique [0002] For a given lateral resolution, the lateral aperture required for radar imaging is proportional to the wavelength. Compared with microwave radar, terahertz radar has a shorter wavelength, and the same imaging resolution can be obtained with a smaller lateral aperture. Therefore, high-resolution azimuth-elevation imaging can be achieved by using the small-angle two-dimensional rotation of the target in the terahertz frequency band; at the same time, since the roughness of the target surface can be compared with the wavelength in the terahertz frequency band, it can no longer be regarded as an ideal For a smooth surface, the number of scattering points increases sharply in the imaging result of the target, showing the ...

AI Technical Summary

Problems solved by technology

In the existing array-based U-V interference 3D imaging method in the terahertz frequency band, the large number of array elements will lead to high complexity of the imaging system; the imaging performance of the synthetic aperture imaging system based on broadband signals is severely restricted by the nonlinearity of the terahertz signal source signal

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