Inspecting and monitoring oil-gas pipelines, roads, bridges, canals are very important in ensuring the reliability and life expectancy of these civil systems. An autonomous Unmanned Aerial Vehicle (UAV) can decrease the operational costs, expedite the monitoring process and be used in situations where a manned inspection is not possible. This paper addresses the problem of monitoring these systems using an autonomous UAV based on visual feedback. A single structure detection algorithm that can identify and localize various structures including highways, roads, and canals is presented in...