Status of ESA's EarthCARE mission, passive instruments payload

EarthCARE is ESA’s third Earth Explorer Core Mission, with JAXA providing one instrument. The mission allows unique data product synergies to improve understanding of atmospheric cloud–aerosol interactions and Earth’s radiation balance. Retrieved data will be used to improve climate and numerical weather prediction models. EarthCARE accommodates two active instruments: an ATmospheric LIDar (ATLID) and a Cloud Profiling Radar (CPR), and two passive instruments: a Multi Spectral Imager (MSI) and a BroadBand Radiometer (BBR). The instruments will provide simultaneous, collocated imagery, allowing both individual and common data products. The active instruments provide data on microscopic levels, measured through the atmospheric depth. 3-D models of the atmospheric interactions are constructed from the data, which can be used to calculate radiation balance. The large footprint of the MSI provides contextual information for the smaller footprints of the active instruments. Data from the BBR allows the loop to be closed by providing a macroscopic measurement of the radiation balance. This paper will describe the passive instruments development status. MSI is a compact instrument with a 150 km swath providing 500 m pixel data in seven channels, whose retrieved data will give context to the active instrument measurements, as well as providing cloud and aerosol information. BBR measures reflected solar and emitted thermal radiation from the scene. To reduce uncertainty in the radiance to flux conversion, three independent view angles are observed for each scene. The combined data allows more accurate flux calculations, which can be further improved using MSI data.