Enhanced Laser Ranging for micro UAV localization

Kurzfassung

Due to the growing number of small and agile unmanned aerial vehicles (UAVs), including consumer micro-drones, appropriate countermeasures technologies are necessary to protect public and military forces, to increase critical infrastructure resilience, and to secure exchange of data. Most of the countermeasure requires reliable up-to-date position information of the approaching threats. Beside precise determination of the angle-of-arrival laser pulse time-of-flight information is one of the promising technologies to measure the distance to a target. Laser Range Finders (LRF) are typically used for long ranges to large objects or slowly moving targets. Within the scope of this paper we are going to show a method to enhance laser ranging capabilities to small and fast-moving UAV targets. Dealing with small and agile targets the primary limitation of many laser ranging systems is the reduced hit rate. The restricted torque of the pan-tilt-unit drives is not able the to align the LRF in the direction of agile UAV targets in the sky. In this paper, we will present a method using an additionally piezo steering device to reduce this residual tracking error. To estimate the improvement, we are going to compare results under same conditions with and without the fast steering device. Experimental evaluations show an improvement of the LRF hit rate during high accelerations of micro UAVs. We present theoretical analysis and experimental results of UAV laser range measurements under realistic environmental conditions.