Geometry-Driven Analysis of Sea-Surface Signatures in Monostatic and Long-Baseline Along-Track Bistatic SAR Configurations: Insights From the PLT-1 Mission
Abstract
This study investigates monostatic and long-baseline along-track bistatic synthetic aperture radar (SAR) geometries for marine remote sensing in the context of the PLATiNO-1 (PLT-1) mission. The analysis focuses on Doppler signatures and normalized radar cross section [normalized radar cross section (NRCS)], i.e., the key observables that underpin ocean wind-field and sea-surface velocity retrieval. An analytical sea-surface scattering model based on the second-order small slope approximation (SSA2) is adopted as a deterministic forward-modeling tool to interpret these observables across polarization and acquisition mode under varying wind conditions and viewing geometries. A practical benchmark is included using real monostatic and bistatic NRCS measurements from the WaddenSAR campaign. The same framework is then applied to an operational PLT-1 simulation scenario to assess geometry-driven variability and the complementarity of monostatic and bistatic observations. Results from the operational analysis highlight the impact of large along-track baselines (ATBs) on azimuthal diversity and on wind-directional sensitivity in both NRCS and Doppler.