Sentinel is a multi-satellite project to be launched from 2014, being developed by ESA under the Copernicus Programme (formerly Global Monitoring for Environment and Security or GMES). The Sentinel missions include satellite radar and super-spectral imaging for land, ocean and atmospheric monitoring.
The Sentinel missions will have the following objectives:
Sentinel-1 (1A launched: 2014/04/03) will provide all-weather, day and night radar imaging for land and ocean services. The first of two Sentinel-1 satellites.
Sentinel-2 will provide high-resolution optical imaging for land services (e.g. imagery of vegetation, soil and water cover, inland waterways and coastal areas). Sentinel-2 will also provide information for emergency services. The first of two identical Sentinel-2 satellites is planned for launch in June 2015.
Sentinel-3 will provide ocean and global land monitoring services. The first of three Sentinel-3 satellites is planned for launch in fall 2015.
Sentinel-5 Precursor - subset of the Sentinel 5 sensor set planned for launch in 2016. The primary purpose of this is to reduce the data gap (especially SCIAMACHY atmospheric observations) between the loss of ENVISAT in 2012, and the launch of Sentinel-5 in 2021. The measurements will be done by the Tropomi spectroscope.