Autonomous River Exploration

Mapping a rivers course and width provides valuable information to help understand the ecology, topology and health of a particular environment. Such maps can also be useful to determine whether specific surface vessels can traverse the rivers. While rivers can be mapped from satellite imagery, the presence of vegetation, sometimes so thick that the canopy completely occludes the river, complicates the process of mapping. Here we propose the use of a micro air vehicle flying under the canopy to create accurate maps of the environment. We study and present a system that can autonomously explore rivers without any prior information, and demonstrate an algorithm that can guide the vehicle based upon local sensors mounted on board the flying vehicle that can perceive the river, bank and obstacles. Our field experiments demonstrate what we believe is the first autonomous exploration of rivers by an autonomous vehicle. We show the 3D maps produced by our system over runs of 100-450 meters in length and compare guidance decisions made by our system to those made by a human piloting a boat carrying our system over multiple kilometers.