A Fully Automatic Method for on-Orbit Sharpness Assessment: a Case Study Using Prisma Hyperspectral Satellite Images

The main objectives of the Sentinel-3 mission are to support ocean forecasting systems, environmental and climate monitoring. However, the coverage of the visible, near-infrared and short-wave infrared portion of the electromagnetic spectrum with a 300 meter resolution and a revisit period of less than 2 days make it very appealing also for vegetation monitoring. In this paper we explore the possibility of using the Sentinel-3 Synergy surface directional reflectances and the PROSAIL model to reliably estimate biophysical variables in general and live fuel moisture content in particular. The latter is a fundamental variable in fire behaviour models and in fire danger assessment, and consequently of high interest in fire management activities. We performed a Global Sensitivity Analysis to identify the most significant PROSAIL parameters in each Synergy channel, and tested the results by implementing a simple Look-Up Table based retrieval algorithm. The outcome shows the potential of biophysical parameter estimation based on this Sentinel-3 product.