Precise Localization in Sparse Sensor Networks using a Drone with Directional Antennas

In this paper, we study a sensor localization technique that replaces fixed anchors with a drone equipped with directional antennas. Our goal is to localize each sensor in the deployment area achieving the localization precision explicitly required by the final user of the sensor networks. Due to the advent of directional antennas, we precisely localize applying a single trilateration for each sensor. To reach the desired precision, we force that each ground distance measured by the drone is greater than a minimum threshold and we set a suitable beamwidth for the directional antennas. Our proposed solution plans a static path for the drone and determines on it the measurements points such that all the sensors are measured at least three times from different antenna orientations. The performance of our solution, evaluated in terms of the static path length and of the achieved precision, is validated by simulation study. With respect to recently published results on sensor localization using flying anchors, our solution finds a shorter path (at least 30\%), localizes all the nodes, and requires a single trilateration for each sensor.