| In recent years, disaster-causing organisms from cold-water intake areas of coastal nuclear power plants, especially shrimp and jellyfish, have gradually become a major hidden danger to the safe operation of nuclear power plants, and monitoring disaster-causing organisms has become increasingly urgent. However, the above disaster -causing organisms usually have the characteristics of high transparency and small size, coupled with the high turbidity of the near-shore water, which make them difficult to be effectively detected by optical equipment. Due to the advantages of good directivity, penetration, and insensitivity to turbidity, sonar detection has become an ideal scheme for detecting the above-mentioned disaster-causing organisms. At present, this detection technology is mainly realized through realtime detecting disaster-causing organisms in a single sonar image. However, due to the complex and changeable marine environment, and the existence of interferences such as tides, the target shape of sonar image is often unclear, and the edge information is easily lost, resulting in the false detection rate and missing detection rate of disaster-causing organism targets high. To solve the above problems, a sonar image processing technology based on sliding window feature aggregation is proposed in this paper. Firstly, pre-process such as sonar image enhancement and tidal interference removal were carried out, to reduce the influence of noise and tidal interference on the monitoring results. Then, continuous video frames are taken as the research object, and feature clustering is carried out by means of a sliding window to obtain the position of fixed objects and eliminate interference. Further combined with Intersection over Union (0IoU) algorithm and Non-Maximum Suppression (NMS) algorithm, disaster-causing organisms in shallow sea areas were accurately identified and detected. The system can realize real-time and accurate monitoring of coastal disaster-causing organisms, and the target detection rate is as high as 96%. This work can improve the accuracy of marine organisms monitoring and early warning in nuclear power plants and maintain the normal operation of nuclear power plants. |