“…The choice of vehicle for positioning sensors directly impacts the scale of research that can be conducted as well as the achievable sensor resolution and associated costs (for review of vehicles, considerations, and limitations, see White et al, 2012;Sankaran et al, 2015). For phenotyping large ecological systems, satellites and manned aircraft remain the only practical option (Kerr and Ostrovsky, 2003;Asner et al, 2012), but small unmanned aircraft systems (UASs) are now a viable alternative for smaller, geographically distinct areas (Kim et al, 2013). Finally, for small-scale experimental field studies, several vehicle options include high-clearance tractors, cable gantries, cranes, linear move irrigation systems, and small UASs in addition to stationary observation platforms (Haberland, 2010;Andrade-Sanchez et al, 2013;Busemeyer et al, 2013a;Chapman et al, 2014;Liebisch et al, 2015).…”