Ground Localization with a Drone and UWB Antennas: Experiments on the Field

In this work, we evaluate the accuracy of the Drone Range-Free (DRF) localization algorithm presented in the literature on a simple test-bed built using the Decawave Ultra Wide Band (UWB) Sensors Kit MDEK1001 and a customary drone. DRF localizes an IoT device at the intersection of the perpendicular bisectors of two chords of its receiving disk. Despite its simplicity and elegance, DRF poses great challenges in a real implementation on the field because the device's receiving disk is in reality far from a perfect circle. We solve this problem by relaxing the range-free assumption and by discovering almost perfect inner-circles in the IoT-device receiving disk using the ability of the MDEK1001 sensors of taking distance measurements. With a set of simplified experiments that aim to localize a single antenna, we show that, using the inner-circle method, we significantly improve on the localization accuracy without loosing the DRF simplicity and elegance. The accuracy of the new inner-circle method, along with that of a simplified range-based multilateration method, is also proved by localizing three antennas posed at the vertices of a pre-determined triangle.