Real-time imaging method of super-resolution millimeter wave MIMO array

Abstract

The invention provides a real-time imaging method of a super-resolution millimeter wave MIMO array. The method comprises the steps of: step (1) performing, by the MIMO array, echo data sampling, and recording a broadband response signal; step (2): obtaining a three-dimensional image of a reflectivity function for a frequency domain response signal by using MIMO RMA, and meanwhile, figuring out animproved coherence factor in a wave number domain; and step (3): correcting the three-dimensional image of the reflectivity function obtained in the step (2) by using the improved coherence factor obtained in the step (2). By adopting the method, the incoherent power of the reflectivity function is re-defined in the wave number domain, so that the calculation of the coherence factor can be completed quickly in one step of three-dimensional IFFT, thereby further improving the imaging speed. In addition, the method still retains the super-resolution performance, comprising improving the spatialresolution, reducing the sidelobe and base noise levels of the image, and significantly improving the dynamic range of the image.

Description

technical field [0001] The invention relates to a synthetic aperture imaging algorithm, in particular to a MIMO array real-time imaging method. Background technique [0002] As an emerging detection energy, millimeter wave has unique advantages. The most notable feature is that it has millimeter-level spatial resolution and has the ability to penetrate plastics, ceramics and some clothing materials, so it is widely used in human body security imaging. In order to improve detection efficiency, a commonly used solution is multiple-input multiple-output (Multi-input Multi-output, MIMO) array imaging. Array imaging methods require imaging instruments with higher numbers of transmit and receive channels, resulting in higher instrument cost and complexity. However, due to the high-speed sampling capability of the MIMO array, it is generally used in occasions with higher real-time requirements, such as human body security inspection in high-traffic occasions. [0003] The real-t...

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Problems solved by technology

[0005] However, the methods listed above are all based on iterative methods, and the amount of calculation is too large, so it is difficult to directly apply them in 3D imaging.

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