Copernicus Sentinel-3 Ocean and Land Colour Instrument (OLCI)

The European Commission, in cooperation with the European Space Agency (ESA), began an ambitious Earth observation initiative called Copernicus to monitor the state of global environment and address climate-change issues. As part of this initiative, ESA developed a series of satellite missions that are called Sentinels. The Sentinel-3 series includes four missions, two, 3A and 3B, that are operationally active, and two, 3C and 3D, that await their launches in 2024 and 2025, respectively. Sentinel-3A was launched on February 16th 2016 and Sentinel-3B was launched on April 25th 2018. Both are multi-instrument platforms that focus on ocean surface topography as well as land and sea surface temperature. Each platform carries the Sea and Land Surface Temperature Radiometer (SLSTR), the Ocean and Land Colour Instrument (OLCI), as well as a Synthetic Aperture Radar (SAR) and a Microwave Radiometer (MWR).

The OLCI instrument was developed in part to provide continuity with measurements made previously by the Medium Resolution Imaging Spectrometer (MERIS) instrument flown on Envisat. OLCI is a visible imaging push-broom radiometer with more spectral bands, improved signal-to-noise ratio, among other improvements, compared to MERIS. The OLCI has 21 spectral bands from 400 to 1200 nm and completely overlaps with SLSTR facilitating the opportunity for fused products. The OLCI swath is not centered at nadir which minimizes the occurrence of sun glint.


Technical Specifications

Orbit: 815 km, 10:00 am. mean local solar time. sun-synchronous, polar
Repeat Cycle: 27 days
Swath Dimensions: 1270 km, global coverage every 4 days
Spacecraft Weight: 1250 kg
Spatial Resolution:

300m full resolution

1200m reduced resolution

Quantization: 12 bits
Field of View: 14.2 deg
Wavebands: 21 bands selectable across range:  400 nm to 1020 nm
Design Life: 7.5 years
Duration: operational
Operator: EUMETSAT

Channels (Bands)

OLCI Band Band centre λ (nm) Band Width (nm) Application
Oa1 400.00 15 Aerosol correction, improved water constituent retrieval
Oa2 412.50 10 Yellow substance and detrital pigments (Turbidity).
Oa3 442.50 10 Chl absorption max biogeochemistry, vegetation
Oa4 442.00 10 High Chl, other pigments
Oa5 510.00 10 Chl, sediment, turbidity, red tide.
Oa6 560.00 10 Chlorophyll reference (Chl minimum)
Oa7 620.00 10 Sediment loading
Oa8 665.00 10 Chl (2nd Chl abs. max.), sediment, yellow substance/vegetation
Oa9 673.75 7.5 For improved fluorescence retrieval and to better account for smile together with the bands 665 and 680 nm
Oa10 681.25 7.5 Chl fluorescence peak, red edge
Oa11 708.75 10 Chl fluorescence baseline, red edge transition.
Oa12 753.75 7.5 O2 absorption/clouds<comma> vegetation
Oa13 761.25 2.5 O2 absorption band/aerosol corr.
Oa14 764.38 3.75 Atmospheric correction
Oa15 767.50 2.5 O2A used for cloud top pressure, fluorescence over land.
Oa16 778.75 15 Atmos. corr./aerosol corr.
Oa17 865.00 20 Atmos. corr./aclean word to html convertererosol corr., clouds, pixel co-registration.
Oa18 885.00 10 Water vapour absorption reference band. Common reference band with SLST instrument. Vegetation monitoring.
Oa19 900.00 10 Water vapour absorption/vegetation monitoring (max. reflectance)
Oa20 940.00 20 Water vapour absorption, atmos./aerosol corr.
Oa21 1020.00 40 Atmos./aerosol corr.