An unmanned aircraft vehicle system for boundary-layer flux measurements over forest canopies

Describes a system design of an unmanned aircraft vehicle (UAV) system for boundary-layer measurements of carbon dioxide fluxes, particularly of those fluxes over forest canopies. The system is aircraft-based, which permits measurements that are difficult to obtain by ground-based line-of-sight instruments (e.g., lidar). The system is unmanned, which permits flux measurements to as low as 5 m above a forest canopy. At altitudes below 30 m, the potential for pilot error and aircraft loss increases, particularly during night flight. This paper outlines some of the major reasons behind the design decisions for the described UAV system.