A Radar Multi-Target Detection Method Combining Clutter Suppression and Gridded frft Processing

Abstract

The invention relates to a radar multi-target detection method combined with clutter suppression and gridded FRFT processing, and belongs to the technical field of radar signal processing and target detection. The present invention firstly solves the problem that the search range of two independent variable parameters and the search step size that conventional FRFT domain target detection is faced with are difficult to quantify, and establishes a Doppler-acceleration two-dimensional search grid; then for Doppler-acceleration two-dimensional Search each grid point in the grid, and use adaptive matched filter technology to form FRFT spectrum after clutter suppression, which improves the signal-to-noise ratio; finally, use subspace projection technology to solve the problem of multi-target detection. Compared with the conventional FRFT domain target detection method, the radar multi-target detection method based on FRFT processing provided by the present invention has clear parameter search grid, good signal-to-noise ratio improvement performance, strong multi-target detection ability, and is suitable for engineering realization. advantage.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing and target detection, and particularly relates to a target detection technology in radar target detection. Background technique [0002] Wide-band narrow-band radar (for example, Multiple-Input Multiple-Output (referred to as MIMO) radar) can obtain long-term observation of the target, and then can perform long-term coherent accumulation processing on the target echo energy to improve the signal-to-noise ratio. Improve radar target detection performance. However, in the long-term coherent accumulation process, due to the instability of the target itself, the change of radar observation angle, and the improvement of Doppler resolution brought about by long-term accumulation, the target Doppler is prone to diffusion, and then As a result, the target energy is not well accumulated. Fractional Fourier Transform (FRFT) processing can effectively solve this problem, especially for the ...

AI Technical Summary

Problems solved by technology

However, for radar target detection, the two parameters p and u lack clear physical meanings, so there are relatively large subjective factors when determining the search range and search step of p and u (except for the search range of p) , resulting in a lack of basis for the determination of the FRFT domain search grid. At the same time, the FRFT domain search grid may increase the amount of calculation because it is too fine, or it may lose the target because it is too coarse.

[0006] 2) SNR improvement in FRFT domain

But in fact, the target and the clutter may occupy some of the same (p,u) parameter units, and the clutter energy will also be accumulated while accumulating the target energy, so the improvement of the signal-to-noise ratio is not optimal

[0008] 3) Multi-target detection problem in FRFT domain

However, this method is only applicable to the case where the strong target is very strong, otherwise the random initial phase of the strong target cannot be accurately estimated; at the same time, a higher requirement is placed on the search step size of the two-dimensional parameters in the FRFT domain to ensure that (p, u) Estimation accuracy of parameter set

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