UAVSAR for NISAR Solid Earth Calibration and Validation

We establish a workflow for validating NISAR Solid Earth Science (SES) products based on UAVSAR measurements of secular velocities and coseismic displacements across earthquake faults. UAVSAR is an L-band synthetic aperture radar capable of measuring solid Earth deformations through repeat pass interferometry. High spatial resolution makes UAVSAR especially sensitive to surface deformation at short spatial wavelengths (e.g., near a crustal fault). Furthermore, UAVSAR acquisition schemes can provide a 3D picture of deformation. For NISAR validation, secular (interseismic) deformation will be measured across the creeping section of the San Andreas fault, where fault creep presents a well-defined tectonic signal and a rich UAVSAR data archive exists. The UAVSAR measurements will be quantitatively compared to measurements based on satellite InSAR data. The workflow developed herein is similar to that in the SES algorithm theoretical basis document (ATBD) for validating NISAR products, with changes made to account for the peculiarities of UAVSAR data.