Study On The Underwater Broadband Light Source For Underwater Spectral Imaging

Faced with problems such as global resources shortage and environmental degradation,much attention has been paid to the ocean.During the period of 12th"Five-Year" in China,the construction of "Digital Ocean" is one of the most important tasks,making marine research a hot spot.Underwater spectral imaging technology can express the object quickly and intuitively,which has a great prospect in the effective detection and recognition of submarine targets.However,unfortunately,it succers form the attenuation of light underwater,which may become a bottleneck of its further development.In order to solve such problems,this paper aims at designing a kind of underwater broadband light source based on the needs of underwater spectral imaging.This paper includes three aspects:1.Experiment to analyze and calculate the minimum spectral irradiance of the underwater broadband light source.2.Design of the optical system and the external cavity.3.Improve underwater light source test method and design light source test system to study illumination characteristics of the underwater light source,and verify whether the underwater broadband light source meets the needs of the underwater spectral imaging system.Based on the underwater spectral imaging system(including filter,camera,lens,etc.)developed by the project team,the minimum spectral irradiance required for normal operation of the system is explored.Considering the attenuation characteristics of light underwater,the minimum spectral irradiance of the light source is analyzed,and the specific parameters of the light source design are provided.By analyzing and comparing the characteristics of different light sources,considering the working condition,volume,cost,operability and other factors,the LED combined light source is selected and manufactured,and the external cavity is designed.Underwater light source test system is designed to obtain the spectral irradiance of the light source at different points in the water,and to study the law of the spectral irradiance of the light source with the underwater illumination distance and its spatial distribution.Underwater spectral imaging experiments show that underwater broadband light source meets the design requirements,and color imaging experiments show that underwater broadband light source is better than the general underwater light sources in terms of performance of underwater color reproduction.The innovation of this paper is to design the underwater broadband light source from the energy spectrum of the spectral band,and further improve the test scheme of underwater light source.According to the test scheme,the experiment can obtain the spectral irradiance of different position of the light source underwater,and explore its distribution rule.The results of this paper can be used in underwater spectral imaging,underwater color imaging and other underwater imaging,which have a higher requirement for underwater color reproduction.