Research On Intelligent Suppression Of Radar Sea Clutter And Small Target Detection Methods

Marine target detection with radar has important application value in coastal surveillance,maritime distress search and rescue,and marine environment monitoring.In the process of sea detection,the detection performance of radar for typical small targets such as surface skiffs,fishing boats and buoys can be seriously degraded by the influence of complex characteristics of sea clutter,which cannot fulfill the practical application requirements for fine sensing of surface targets.Therefore,the radar sea clutter suppression and small target detection with important research significance has become a frontier hot problem that needs to be solved in the international arena.Its core includes sea clutter modeling analysis,intelligent sea clutter suppression and accurate detection of small targets.In this thesis,the research of sea clutter characteristic analysis and modeling,sea clutter intelligent suppression and small target detection methods are carried out to address these problems,and the research methods are verified by experiments.The detailed research contents are as follows.1.Based on the analysis of the scattering characteristics and statistical properties of sea clutter,a composite K-distribution radar sea clutter model is investigated.The generated sea surface echo simulation data under radar scanning operation mode effectively reflects the non-Gaussian characteristics and space-time correlation properties of sea clutter.The contribution is to lay the foundation for the research of sea clutter suppression and small target detection.2.A radar sea clutter intelligent suppression method is proposed.The characteristics of sea clutter data are learned via the established ring-symmetric sea clutter suppression network.By converting the radar data domain before sea clutter suppression to the data domain after suppression,the information of marine targets is retained.The effective suppression of sea clutter is finally achieved.3.A method of small target detection based on saliency-enhanced fusion is proposed.A fused saliency map is constructed by extracting the multidimensional features of the target and utilizing it for the likelihood ratio calculation,which improves the inter-frame accumulation performance of the target.The accurate detection and tracking of small targets on the sea surface under low signal-to-noise ratio conditions is implemented.The effectiveness of the above method has been verified on the simulated and measured radar data.The results show that the proposed intelligent sea clutter suppression method can effectively suppress sea clutter while retaining the complete information of the target;the proposed target detection method can realize the accurate detection of small targets on the sea surface under the condition of low signal-to-noise ratio.