Spinning target time-varying three-dimensional imaging method based on linear frequency modulation stepped signal

Abstract

The invention provides a spinning target time-varying three-dimensional imaging method based on a linear frequency modulation stepped signal. The spinning target time-varying three-dimensional imaging method comprises the steps of: step 1, subjecting data echo to ''Dechirp'' and translational motion compensation processing, carrying out range-slow time imaging, processing an obtained coarse-resolution range image, and synthesizing to obtain a fine-resolution range image; step 2, extracting echo curve parameters of scattering points in the fine-resolution range image through Hough transform, further acquiring echo trajectories of the scattering points; step 3, and performing interference processing on three antenna echoes along the trajectory directions to obtain two-dimensional coordinates, further performs range walk compensation on range direction positions represented by the trajectories to obtain three-dimensional coordinates, and finally acquiring a three-dimensional image of the scattering points through integrating the obtained three-dimensional coordinates. According to the spinning target time-varying three-dimensional imaging method, the linear frequency modulation stepped signal has a narrow instant bandwidth and has a large synthetic bandwidth at the same time, and the spinning target time-varying three-dimensional imaging method can be applied to a narrowband radar to improve the imaging quality and reduce the burden on a hardware system.

Description

technical field [0001] The invention relates to signal and information processing technology, in particular to a spin target time-varying three-dimensional imaging method based on a linear frequency modulation step signal. Background technique [0002] In recent years, with the rapid increase in the number of space objects such as space debris, satellites, and ballistic missiles, the space environment has become increasingly complex. Carrying out space object tracking, measurement, classification, and identification is crucial to ensuring my country's space security, promoting the development of national space technology, and space peace. Utilization is very important. [0003] As an important means of space surveillance, radar imaging technology plays a significant role in target classification and recognition. Since space targets mostly have various forms of micro-motion such as spin, precession, and rollover, each scattering point on the target will move across the distan...

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Problems solved by technology

However, when the above methods obtain the real 3D imaging results and 3D micro-motion features of the target, they all need to jointly process the echoes of multiple radars located at different angles of view. Anisotropy, occlusion effects and other issues, and the system implementation is more complicated

In order to solve the above problems in the 3D imaging method of space targets, an interferometric 3D imaging method in narrowband radar was proposed (see Chen Yongan's "Multi-antenna Interferometric Processing of Narrowband Radar Space Rotating Target 3D Imaging", published in "Journal of Air Force Engineering University (Natural Science Edition), 2016, No. 17), through the interferometric calibration of the echoes of different scattering points in the time-frequency domain, but due to the low range resolution of narrowband radar, it is impossible to obtain the range direction of each scattering point. the real coordinates of

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