Research On The Underwater Large-scale Optical Field Distribution

The 21st century is the marine world, many countries are taking exploration of marine resources to a in-depth research, and development in various fields of marine exploration techniques have been greatly promoted. The underwater de-tection technology can be divided into acoustic detection technology and optical detection technology. While optical detection under water are able to meet the human eye intuitionism, so the study of underwater optical imaging of the under-water world will play a very important role in exploring oceans resources.In this thesis, according to the progress in the field of marine underwater imaging optical detection in recent years,and through the research and analy-sis of the optical properties of water medium, based on the relevant theory of the illumination discipline, some purely optical measurement concepts (such as light intensity, luminous flux etc.) were imported into underwater optics. That makes the underwater light field energy distribution can use mathematical analy-sis to describe. Underwater vision systems commonly using in attenuation length, volume scattering function, water visibility were analyzed on micro and macro, and the effectiveness of measuring water visibility of the laboratory environment were established. The research on the energy concept and the underwater image contrast transmission were carried out, leading to the establishment of the un-derwater auxiliary lighting vision system imaging effectiveness evaluation criteria based on the visual threshold. It notes that the effectiveness of standard auxiliary lighting underwater vision system is not only dependent on the validity of the il-lumination intensity of the light source, but also on the geometrical configuration of the light source system, the receiver CCD, the object, which ultimately affect the underwater target maximum imaging distance and imaging quality.following this standard of "evaluation criteria", this thesis proposed the re-search and design of large-scale underwater light field, the feature of "large-scale" is reflected in two ways:long imaging distance and the large depth of field. A dis-tance of 2 times visibility observation of underwater object were implemented in this step with the equipment of biconvex lens cluster light source (BILC), the light intensity measurement was implemented, validating that the optical parameters are consistent with the design criteria. At the same time using the combination of biconvex lens cluster light source (BILC) and Fresnel lens cluster light source (FNLC), the depth of field limitation on the field axis of view was overcome while realizing the need of 2 times visibility observation of underwater object.