Underwater Wide-Area Layered Light Field for Underwater Detection

Abstract

In underwater electro-optic detection, image quality can be degraded by the backscattering of light from the illuminated water volume. In practical systems, we tend to simultaneously require a high level of detection distance (DD), field of view (FOV), and depth of field (DOF), but these factors influence each other by the media scattering. To eliminate this restriction, we propose to explore the underwater wide-area layered light field (UWLLF), which classifies the underwater detection area by the DD and distribution characteristics of the light field, to minimize the scattering influence on target detection. Based on the UWLLF, an underwater electro-optic detection system is designed that can achieve the specifications of a 70° FOV and 7.9-fold attenuation length (for the attenuation coefficient 1.43 /m of 532 nm) DD. In addition, with the spatial separation of light energy, the non-detection zone at short ranges is eliminated, yielding an almost full DOF. With these three factors simultaneously improved, the ability of underwater exploration for object detection is enhanced.

Keywords

• Underwater technology
• optical imaging
• object detection
• light field
• underwater detection