Research on key Technologies of underwater Target Detection

摘要

The traditional underwater detection methods using sonar have some limitations, for example, in close range detection, the low frequency detection ability of sonar system is weak and the detection accuracy is low. In this paper, a new type of fiber Bragg grating hydrophone which can detect low frequency signals is developed. the hydrogel and fiber grating are combined in structure, and a combined packaging structure is designed, which can effectively improve the low frequency sensitivity of the hydrophone. The new fiber Bragg grating hydrophone works in the frequency range of 50-1000Hz and has good response characteristics for underwater low frequency signals. Underwater optical detection technology has high detection accuracy in close range detection, and will become a powerful supplement to underwater acoustic detection technology. However, in the water environment, the contrast of the image obtained by the optical imaging system is very low, so it is difficult to process and analyze the image information effectively. In this paper, the underwater polarization imaging system and algorithm are studied, and a target enhancement technology of underwater polarization imaging based on generating countermeasure network is proposed.Firstly, the circularly polarized light is used for active illumination, and then the underwater polarization imaging based on Stokes vector is carried out, and the images of different polarization states are collected respectively. finally, these polarization images are input into the generation countermeasure network trained by "combined image restoration of circular polarization and linear polarization", and the polarization images are fused to generate multi-polarization high-resolution fusion images.