First Results of the 3D Ground Displacements Retrieval through Capella Space Mid-Inclination Orbit DInSAR Measurements: the Campi Flegrei Caldera Case Study

In this work we present the first results achieved by processing three interferometric Synthetic Aperture Radar (SAR) datasets acquired between late June and August 2024 by the Capella Space satellite Capella-14, with a repeat cycle of approximately 3 days and operating at a 45° mid-inclination orbit (MIO). An MIO Differential SAR Interferometry (DInSAR) configuration can measure displacements also along the North-South direction, offering complementary insights to those provided by sun-synchronous satellites. For this reason, this study focuses on the Campi Flegrei caldera (Italy), an area characterized by significant ground deformation due to the bradyseism phenomenon, which has been in an uplift phase since 2005. The SAR data are processed using the Parallel Small BAseline Subset (P-SBAS) technique, and the first results detailing Line of Sight (LOS) displacements are presented. This work highlights the potential of upcoming SAR missions optimized for MIO configurations, such as the NIMBUS SAR sub-constellation within the forthcoming Italian IRIDE constellation.