Mission Considerations for Future MEO SAR Systems

Abstract

Low Earth Orbit Synthetic Aperture Radar (LEO SAR) systems, at altitudes below 1000 km, have a limitation in regard to their instantaneous coverage on Earth and their long revisit time to the areas of interest. A suggested way to overcome these limitations is to go towards higher orbital altitudes. Increasing orbital altitude towards medium Earth orbit (MEO) heights, at altitudes varying from 2000 to 35768 km, provides advantages with respect to spatial coverage, global temporal revisit times and communications infrastructure. This paper discusses various design aspects of MEO SAR missions. It presents the main challenges in performance and shows they can be overcome for moderate resolution systems. It then describes the ability of MEO SAR to provide global coverage in 1- to 2-day revisit or continental/oceanic coverage with multi-daily observations, making MEO SAR very attractive for future scientific missions with specific interferometric and polarimetric capabilities.