VGT P Processing
Three ADFs are used during the specific VGT-P algorithm included in the global SYN processing:
- The VGT-P Radiative Transfer Simulation data file is similar to the one used in the SYN Level-2 algorithm. The difference is that a standard continental aerosol model with aerosol optical thickness from climatology is assumed. As a consequence, aerosol optical thickness is derived directly from latitude and the ADF is smaller than that used in Level-2 processing.
- The VGT-P Spectral Response Function data provides information used in computation of the specific spectral bands defined for VGT-P products. VGT-P processing uses linear interpolation to form a hyper spectral surface reflectance spectrum and this spectrum is then filtered according to the spectral response function of the VGT bands to obtain simulated reflectance. These spectral responses are gathered in this file, also providing the hyper-spectral solar irradiance.
- The VGT-S Radiative Transfer Simulation data file is restricted to VGT channels, instead of OLCI and SLSTR channels and, as a consequence, is similar to, but smaller than the file related to VGT-P processing.