The objective of the EarthCARE mission is to make global observations of clouds, aerosols and radiation.

To achieve this challenging objective the satellite carries four scientific instruments and circles Earth in a Sun-synchronous polar orbit crossing the equator in the early afternoon to optimise daylight conditions.

The payload comprises two active instruments: a high-resolution atmospheric lidar and a radar, and two passive instruments: a multispectral imager and a broadband radiometer.

The lidar and radar observe the atmosphere underneath the satellite flight path. Vertical profiles of aerosols and thin clouds can be obtained using the lidar. Profiles of thicker clouds require the use of the radar because laser light would not be able to penetrate deep enough into a thick cloud.

The combination of lidar and radar observations will deliver vertical profiles underneath the satellite flight track, but no information on either side of it.

For this purpose, the satellite carries a multi-spectral imager that will provide cloud and aerosol information in the direction perpendicular to the lidar and radar measurements. The data processing of lidar, radar and imager together will then allow for the construction of 3D cloud and aerosol scenes.

The fourth instrument will measure, at the same location and from different angles, the outgoing reflected solar radiation and the emitted thermal radiation from Earth. The combination of these observations will finally allow clouds and aerosols to be quantitatively linked to radiation.

EarthCARE is scheduled for launch in 2015. It has a design lifetime of three years, including a six-months commissioning phase.

The satellite data will be downlinked to a high-latitude ground station and the instrument data will be processed up to Level 1 by ESA for the lidar, imager and radiometer, and by JAXA for the radar.

Both ESA and JAXA will distribute these data and geophysical Level 2 data to their respective users.