Uncrewed Aerial Vehicle (UAV)-Based, K-Band Interferometric Synthetic Aperture Radar (SAR)

The paper proposes the study and development of Interferometric Synthetic Aperture Radar (InSAR) from compact, high-frequency radar sensors onboard commercial Unmanned Aerial Vehicles (UAVs, often referred to as “drones”) to create precision Digital Elevation Models (DEMs). The potential of such InSAR systems, due to the higher operating frequency and target proximity, is quantified, but it is also shown how the same features, combined with the instability of UAV platforms, lead to motion errors that either deteriorate or altogether deny capability. The paper thus quantifies acceptable motion error limits and shows how complex autofocus can restore height estimation performance, through analytical modelling that is verified by simulation and validated through outdoor experiments with a 24 GHz UAV-based demonstrator. To our knowledge this is the first demonstration of a UAV-based InSAR system in this high-frequency band.