Radar-Based High-Accuracy 3D Localization of UAVs for Landing in GNSS-Denied Environments

Global navigation satellite systems (GNSS) such as GPS are the de-facto standard for absolute and reliable unmanned aerial vehicles (UAV) localization due to their global availability and the maturity and wide spread of the underlying technology. However, as the spread and reliance upon autonomous UAV systems increases, the risk of jamming becomes a substantial safety problem. The area where jamming attacks are most likely to occur is the close vicinity of the UAV landing station. Hence, to ensure reliable operations, an alternative localization technology for the approach and landing phase is needed. This paper presents a localization system for 3D position estimation based on 24 GHz FMCW cooperative radar. It has very low infrastructure requirements thanks to the combination of ranging and direction-of-arrival (DOA) estimation techniques employed in the ground station. Jamming resistance is improved due to the large bandwidth of 250 MHz. A measurement campaign was conducted to prove the feasibility of the proposed concept.