Enhanced active target detection in fog.

摘要

Understanding and improving vision through fog and other scattering media has been a significant research area during the last century. Substantial knowledge has been gleaned from various scientific and engineering projects conducted in this period. Still, impaired vision due to fog wrecks havoc on the many forms of transportation that depend on vision as the primary source of navigation and guidance information.; This thesis details an investigation into the performance of several enhanced vision techniques, determining their advantages and disadvantages when imaging active targets through fog. To support this tech, a low cost visibility sensor was designed to assist visual characterization of various marine advection fog events. This sensor was used during a series of field trials to evaluate the potential of visible and infrared technologies to enhance vision through fog. One system, polarization difference imaging, was found to have superior characteristics and could be used to improve visual guidance activities, such as helicopter operations on the Grand Banks, in degraded weather conditions. A design of a dedicated hardware, real-time target acquisition and tracking system based on polarization difference imaging suitable for enhanced guidance activities is proposed and discussed in detail. Ultimately, this research investigates the performance of several enhanced vision technologies in fog and proposes a solution that will improve offshore aviation in poor visibility conditions.