Spaceborne Observations of the Coastal Zone

Abstract The dynamic nature of coastal zones necessitates regular and precise monitoring to understand their ever-changing states and address critical societal and environmental challenges. Advances in spaceborne technologies, including optical imagery, radar, and altimetry, have significantly enhanced our ability to observe and analyse coastal and littoral dynamics. Current approaches, such as Satellite-Derived Shorelines (SDS), provide indirect measurements of coastal changes, though more complex products like bathymetry and topography are gaining accuracy and traction. Emerging missions like CO3D and SWOT introduce transformative capabilities. CO3D employs instantaneous stereo mode to achieve high-resolution, instantaneous 3D reconstructions of wave dynamics, ocean currents, and coastal topography, while SWOT’s swath altimetry delivers direct measurements of the free-surface, limitedly affected by typical challenges of optical sensors like cloud cover. These innovations enable detailed insights into wave attenuation, sandbar interactions, and large-scale coastal processes. This paper reviews the current and future potential of spaceborne sensors to monitor coastal zones, emphasizing their role in providing robust, large-scale observations to address key scientific and societal questions. Integration of these technologies offers a comprehensive framework for advancing coastal research and management strategies, supporting sustainable development and risk assessment in vulnerable coastal areas.