  Drones are not fully trusted yet. Their reliance on radios and cameras for
navigation raises safety and privacy concerns. These systems can fail, causing
accidents, or be misused for unauthorized recordings. Considering recent
regulations allowing commercial drones to operate only at night, we propose a
radically new approach where drones obtain navigation information from
artificial lighting. In our system, standard light bulbs modulate their
intensity to send beacons and drones decode this information with a simple
photodiode. This optical information is combined with the inertial and altitude
sensors in the drones to provide localization without the need for radios, GPS
or cameras. Our framework is the first to provide 3D drone localization with
light and we evaluate it with a testbed consisting of four light beacons and a
mini-drone. We show that, our approach allows to locate the drone within a few
decimeters of the actual position and compared to state-of-the-art positioning
methods, reduces the localization error by 42%.
