An overview of the EarthCARE mission and end-to-end simulator

The Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) mission aims at improving the representation and understanding of the Earth's radiative balance in climate and numerical weather forecast models by acquiring vertical profiles of clouds - including vertical motion within clouds - and aerosols, as well as measuring the broadband radiances at the top of the atmosphere for flux estimates in relation of the observed clouds and aerosols fields. The EarthCARE payload comprises an High Spectral Resolution (HSR) Lidar (ATLID) operating at 355 nm and equipped with a high-spectral resolution (HSR) receiver and the Cloud Profiling Radar (CPR), a highly sensitive 94GHz cloud radar with Doppler capability. A Multi-Spectral Imager (MSI) supporting the active instruments consists of a push-broom imager with 7 channels in the visible, near infrared, short-wave infrared and thermal infrared. Finally, a Broad-Band Radiometer (BBR) measures the outgoing top-of-atmosphere radiances in a short wave channel and a total wave channel, from which the long wave contribution can be deduced. The EarthCARE end-to-end Simulator (ECSIM) encompasses the full EarthCARE observation chain from scene definition to single-instrument and synergistically derived multi-instrument Level 2 products. Level 2 retrieval algorithms can be tested in the full chain (provision of input data, algorithm performance tests by comparison of outputs with known inputs) by using a single framework with well-defined interfaces helping to harmonise algorithm developments. The CPR is developed and procured by JAXA (Japanese Aerospace Exploration Agency) and NiCT (National Institute of Information and Communications Technology) and will be embarked as an integral part of the EarthCARE satellite in the context of the ESA/JAXA cooperation for EarthCARE.