Joint retrieval of surface reflectance and aerosol properties from PROBA-V observations, part I: Algorithm performance evaluation

CISAR, a novel and versatile algorithm for the joint retrieval of surface reflectance and aerosol properties, has been applied on PROBA-V observations from years 2014–2015 in the framework of the Advanced Land, Aerosol and Coastal products for PROBA-V (PV-LAC) ESA project. This algorithm allows a continuous variation of the surface and atmospheric state variables in the solution space as it solves the solution of the radiative transfer equation online. The inversion is performed with an Optimal Estimation (OE) approach, which finds the best balance between the information that can be derived from the observations and the prior information. Retrieval uncertainties are also estimated from the OE theory and these account for both observation and prior information uncertainties. The role of temporal information in regulating possible surface and aerosol variations is analysed in this paper against simulated PROBA-V observations.