  Many unmanned aerial vehicle surveillance and monitoring applications require
observations at precise locations over long periods of time, ideally days or
weeks at a time (e.g. ecosystem monitoring), which has been impractical due to
limited endurance and the requirement of humans in the loop for operation. To
overcome these limitations, we propose a fully autonomous small rotorcraft UAS
that is capable of performing repeated sorties for long-term observation
missions without any human intervention. We address two key technologies that
are critical for such a system: full platform autonomy including emergency
response to enable mission execution independently from human operators, and
the ability of vision-based precision landing on a recharging station for
automated energy replenishment. Experimental results of up to 11 hours of fully
autonomous operation in indoor and outdoor environments illustrate the
capability of our system.
