Research On Key Technologies Of Underwater-to-air Imaging

China not only has a vast land and resources,but also has a coastline of more than18,000 kilometers and a sea area of nearly 3 million square kilometers.It also belongs to a large maritime country.China’s sea area contains abundant resources,and the active development and utilization of marine resources is conducive to the sustainable development of our economy.Submarines,as a kind of ship that can sail underwater,are not only used as important marine strategic weapons,but also play a pivotal role in the field of deep sea exploration.The danger found.Because of the limitations of traditional periscopes on submarines,virtual periscope technology came into being.The virtual periscope is a new type of underwater air-to-air imaging system,which can observe the water target through the water-air interface at a safe distance underwater,thereby avoiding danger while working effectively.Based on the application and development of virtual periscope,this paper has conducted a detailed study on the key technologies of underwater air-to-air imaging.The main research contents include the following:(1)The research progress of the application of virtual periscope is summarized,and the restoration technology of the underwater air-to-air imaging distorted image is analyzed and summarized from the aspects of image sequence and water ripple reconstruction.(2)An underwater air-to-air imaging model is constructed,and the transmission characteristics of light underwater and the transmission characteristics of light at the airwater interface are studied respectively,and the three-dimensional simulation process of ocean waves is briefly introduced.(3)Based on the distorted image restoration technology of water ripple reconstruction,an experimental method of wave restoration is designed.According to the principle of small hole imaging,the surface gradient information of random waves is converted into spot displacement information after small hole imaging,and the correlation between the spot displacement information and the wave surface gradient is obtained through theoretical research,and the wave based on the law of refraction and the displacement field is proposed Two methods of surface gradients.Then the surface height is solved according to the wave surface gradient to realize wave reduction.(4)On the basis of(3),a correction method for distorted images is proposed.First,the ray tracing theory and related algorithms are introduced.According to the camera imaging principle,all pixels of the distorted image are mapped to a three-dimensional plane in the air through ray tracing,and then the distortion-corrected image is restored on the threedimensional plane.(5)Based on the theories mentioned in(3)(4),simulation and verification experiments were carried out on the matlab platform respectively,wave restoration and distortion image correction were completed according to the experimental method,and the experimental results were analyzed.