Three-dimensional synthetic aperture radar imaging method based on electromagnetic vortex waves

Abstract

The invention discloses a three-dimensional synthetic aperture radar imaging method based on electromagnetic vortex waves. The method mainly solves the problem that according to existing two-dimensional imaging methods, only relative stillness of an object and a radar is taken into consideration. The method comprises the steps that 1, the electromagnetic vortex waves with different orbital angularmomentum are emitted; 2, range compression and range migration correction are conducted on received echo signals; 3, deramping operation is conducted in the heading direction to obtain a focus imagein the heading direction; 4, the scene center is regarded as reference, and Doppler cell migration correction is conducted on the focused image in the heading direction; 5, Fourier transformation is conducted in an orbital angular momentum field to obtain a three-dimensional image, and then according to angle transformation relations, a final three-dimensional synthetic aperture radar image is obtained. According to the method, by means of the orbital angular momentum carried by the electromagnetic vortex waves in combination with relative motions of the object and the radar, three-dimensionalsynthetic aperture radar imaging is achieved.

Description

technical field [0001] The invention belongs to the technical field of radar, and further relates to a synthetic aperture radar (Synthetic Aperture Radar, SAR) three-dimensional imaging method in the technical field of radar imaging. Background technique [0002] Synthetic aperture radar has been widely used in military and civilian fields such as strategic defense and terrain surveying and mapping because of its all-day, all-weather, and long-range imaging capabilities. Traditional SAR can only acquire two-dimensional images on an oblique plane, and is affected by overlap and perspective shrinkage. In order to overcome the defects of two-dimensional imaging, scholars at home and abroad have proposed a variety of three-dimensional SAR imaging methods. At present, 3D SAR imaging has become one of the research hotspots of modern radar. [0003] As one of the main technologies to realize 3D SAR imaging, the downward line-of-sight linear array 3D SAR system has attracted the a...

AI Technical Summary

Problems solved by technology

However, there are two main problems in the downward line-of-sight linear array 3D SAR: the vertical heading resolution is affected by the size of the array, which is usually lower than the resolution along the heading and range; to avoid blurred images, the array elements in the vertical heading The spacing must be small enough to result in a large increase in the number of elements

However, the current research is limited to the fact that the radar and the target are relatively stationary, and only two-dimensional images of the target can be obtained.

Images