The ESA EarthCARE Mission. Development of 3 along-track views angular dependence models for improved radiance to flux conversion

ABSTRACT The EarthCARE (Earth Clouds, Aerosols and Radiation Explorer) Broad Band Radiometer (BBR) will measure Top-of-Atmosphere (TOA) broadband radiance measurements to provide estimates of radiative fluxes at the Earth’s TOA. EarthCARE will also carry an advanced lidar (ATLID), a cloud profiling radar (CPR) and a Multi-spectral imager (MSI), and is scheduled for launch in 2012. For the EarchCARE BBR, Angular Dependence Models (ADMs) are required for the radiance-to-flux conversions. A set of ADMs for the EarthCARE-BBR instrument has been derived by using TOA radiances and fluxes simulated by the Monte-Carlo photon transport algorithm in the EarthCARE Simulator. More than 80.000 detailed atmospheric scenes were defined, taking into account foreseen specific orbital constraints, four different land surface types, and four ocean surface types (under four different wind speed conditions) with corresponding atmospheric/surface/cloudy interrelated conditions; and including a fine aerosol/cloud classification and discrimination. The simulations were processed on the Grid on-Demand ESA-ESRIN interface (more than 80 CPUs), as well as on UVEG Computing Centre. The EarthCARE-BBR radiometer will make measurements at nadir and in the along-track direction at two symmetric off-n