UAS-Based SAR Repeat-Pass Interferometry With Ground Truth

Radar systems operating aboard unmanned aerial systems (UASs) or drones are gaining lot of interest in the remote sensing field. UASs have recently been tested as platforms for synthetic aperture radar (SAR) systems. There are many expectations regarding the interferometric capabilities of UAS-based radar interferometers. Nevertheless, its implementation introduces new problems, which demand advanced processing techniques. To date, only few works presented interferometric data acquired aboard UAS. In this paper repeat-pass interferometric tests are presented, performed with an S-band UAS-based SAR. By using corner reflectors subject to known displacements, the interferometric capabilities of the sensor are demonstrated. Results from two measurement campaigns are presented: data acquired in controlled scenario and in a vegetated slope. A focusing algorithm that considers the UAS position and attitude information, able to cope with the UAS instabilities, is presented and discussed. At the knowledge of the authors, the experimental results obtained are the first systematic demonstration of repeat-pass UAS-based SAR interferometry, validated by ground truth.