Robotic sensors are promising instruments for monitoring spatial phenomena. Oftentimes, rather than aiming to achieve low prediction error everywhere, one is interested in determining whether the phenomenon exhibits certain critical behavior. In this paper, we consider the problem of focusing autonomous sampling to determine whether and where the sensed spatial field exceeds a given threshold value. We introduce a receding horizon path planner, LSE-DP, which plans efficient paths for sensing in order to reduce our uncertainty specifically around the threshold value. We report fully autonomous field experiments with an Autonomous Surface Vessel (ASV) in an aquatic monitoring setting, which demonstrate the effectiveness of the proposed method. LSE-DP is able to reduce the uncertainty around the threshold value of interest to 68% when compared to non-adaptive methods.

@inproceedings{hitz14fully,
	author = {Gregory Hitz and Alkis Gotovos and Francois Pomerleau and Marie-Eve Garneau and Cedric Pradalier and Andreas Krause and Roland Siegwart},
	booktitle = {In Proc. International Conference on Robotics and Automation (ICRA)},
	title = {Fully Autonomous Focused Exploration for Robotic Environmental Monitoring},
	year = {2014}}