The SENTINEL-3 observation scenario implements a pre-defined SENTINEL High Level Observation Plan (HLOP), and is focused on delivering the observation requirements for the Copernicus services. The SENTINEL HLOP can be found here.

The SENTINEL-3 instruments provide the sensing of the data autonomously on-board the spacecraft on the basis of predefined geographic data and selection of observation mode depending on the surface over which the spacecraft is flying. This mode of operation does not require any specific request from users, and ground-based routine operations planning of the spacecraft is extremely simple. The SENTINEL-3 instruments autonomously perform systematic and continuous sensing as follows:

• The OLCI instrument, in observation mode,  acquires data over daylight part of the orbit (i.e. for a sun zenith angle below 80 deg).

In addition, and in order to maintain the performance of the instrument during the mission lifetime, at regular intervals throughout the Mission, the instrument is placed in calibration mode.

For more information on the OLCI coverage please visit the Coverage section of the User Guide.

• The SLSTR instrument, in observation mode, operates the infra-red and SWIR channels over the whole orbit, and the visible channels out of eclipse only. In addition to maintain the performance of the instrument, a calibration mode is also used.

For more information on the SLSTR coverage please visit the Coverage section of the User Guide.

• The SRAL instrument acquires data over the whole orbit in 100% SAR mode.

• The MWR instrument operates over the whole orbit.