Following ENVISAT's AATSR instrument, the SLSTR instrument is a conical scanning imaging radiometer employing the along track scanning dual view technique. SLSTR provides data continuity with respect to these previous missions but with a substantial improvement due to its higher swaths (740 km in dual view and 1400 km in single view).
The OLCI push-broom instrument swath is 1270 km. The OLCI swath is not centred at nadir (as in the MERIS design) but is tilted 12.6° westwards to mitigate the negative impact of sun-glint contamination. Fully overlapping with SLSTR instrument swath and simultaneous acquisitions facilitates the use of OLCI and SLSTR in synergy.
The altimeter instrument (SRAL) does not have a swath like the Sentinel-3 OLCI and SLTSR instruments. Across-track, it receives a single measurement of the range (no image) every time a pulse is emitted.
Data is acquired systematically based on a pre-set nominal mission scenario, as defined in the Sentinel High Level Operations Plan (HLOP):
- Operations for OLCI and the visible channels of the SLSTR are based on specific solar illumination conditions (SZA < 80 deg)
- MWR acquires data over the whole orbit
- SRAL operates in 100% SAR mode
Figure 1: Sentinel-3 Ground Track Resolution (Credit: ESA)