Towards Drone-Based Single-Pass Across-Track SAR Interferometry

Kurzfassung

Drone-based SAR interferometry (InSAR) enables the generation of high-quality digital elevation models (DEMs), which requires not only a wide bandwidth but also interferometric baselines of several meters when op-erating at frequencies between the L and X bands. While in the case of repeat-pass InSAR signal processing is challenging due to non-linear trajectories and low flight altitudes, multi-platform, single-pass acquisition geome-tries are in addition limited by flight safety constraints that make it difficult to obtain feasible interferometric pa-rameters, e.g., height of ambiguity or low baseline decorrelation. In this work, we present a repeat-pass InSAR ex-periment conducted over an area with notable topography, demonstrating the capability to generate high-quality DEMs in a general scenario with topographic variations of the order of the drone flight height. Furthermore, we investigate potential flight formations for multi-platform, single-pass InSAR, showing that parallel and along-track baselines can be introduced to achieve viable InSAR parameters without notable degradation on the inter-ferometric coherence. The investigated aspects are paramount not only to effectively perform single-pass InSAR acquisitions, but also to conduct demonstrations of further multi-baseline SAR concepts achieving parameters representative of spaceborne systems.