Experimental Demonstration of UAV-Based Ultra-Wideband Multi-Baseline SAR Interferometry

Abstract:
Unmanned aerial vehicle (UAV)-based synthetic aperture radar (SAR) interferometry (InSAR) allows for generating digital elevation models (DEMs) with unprecedented height accuracy and resolution over local areas thanks to the use of large baselines and large fractional bandwidths. A detailed DEM performance analysis unveils that under these conditions height accuracies in the order of a decimeter are feasible at spatial resolutions below 0.5 m and simulations also show that radargrammetry is accurate enough to support a pixel-wise absolute phase unwrapping. Based on these theoretical analyses, an experimental demonstration of multi-baseline InSAR is performed. The first experimental results show that the predicted height accuracies with InSAR and radargrammetry can be reached under favorable acquisition geometries and that a more refined InSAR processing is needed to deal with the nonlinearity of the trajectories and the time-variant baselines. The results will pave the way to local height measurements with unprecedented accuracy and resolution.