ARGOS: a Fractioned Geosynchronous SAR

A swarm of N Synthetic Aperture Radar (SAR) sensors in a geostationary orbit would provide all-day-all-weather imaging within a continental region, using direct downloading for real time data exploitation. The coherent combinations of the echoes would improve the signal-to-noise ratio by a factor of N2, leading to metric resolution, 20–40min minimum observation time, multi-polarimetric and interferometric imaging. Fast evolving events like landslides, floods, soil moisture changes, volcanic activity, co-seismic motions, infrastructure deformations and columnar water-vapor maps would be monitored continuously from space for the first time. The observed area would have a footprint up to a thousand kilometers wide, set using electronic steering, anytime, and anywhere within a continent. In this paper, we take advantage of the preliminary concept definition of the “Advanced Radar Geosynchronous Observation System” ARGOS, to provide applications, scalable extension from a single monostatic SAR to a constellation of active and passive sensors, discussion of launch strategies and Radar payload and comparison with concepts proposed in the literature.