“…COT and REF are retrieved using the classical Nakajima and King (1990) approach, which is based on the principle that cloud reflectance is mainly dependent on COT at a non-absorbing, visible wavelength and on REF at an absorbing, near-infrared wavelength. In the CPP algorithm (Stengel et al, 2015;Roebeling et al, 2006), the doubling-adding KNMI (DAK, De Haan et al, 1987;Stammes, 2001) radiative transfer model is used to simulate visible (0.6 µm) and near-infrared (1.6/3.7 µm) TOA reflectances as a function of viewing geometry, COT, REF and CPH. These simulated reflectances are stored in a look-up table (LUT), and satellite-observed reflectances are matched to this LUT in an iterative manner, leading to the derivation of COT and REF.…”