Sentinel-2
A pair of European Earth-observation satellites that image land every few days in thirteen spectral bands at moderate resolution.
Sentinel-2 is a two-satellite mission operated under the European Union's Copernicus programme. Each satellite carries a multispectral imager that records reflected light in thirteen bands, from visible wavelengths through near-infrared and short-wave infrared, at resolutions between ten and sixty metres.
Because the two satellites fly in the same orbit, offset by half a revolution, most land areas are re-imaged roughly every five days. That revisit rhythm makes Sentinel-2 the default workhorse for vegetation monitoring, land-cover change and crop phenology, and it is usually the first dataset a carbon project reaches for when building a monitoring baseline.
Its limits are equally well known: cloud cover blocks optical observation, resolution is too coarse to count individual trees, and short-wave infrared bands saturate over very dense biomass. Serious MRV stacks therefore pair Sentinel-2 with radar, very-high-resolution imagery and ground plots rather than relying on it alone.
Frequently asked questions
Is Sentinel-2 free to use?
Yes. Copernicus data and services are distributed openly, which is why Sentinel-2 underpins most low-cost monitoring programmes.
Why is Sentinel-2 not sufficient on its own for carbon estimation?
Optical imagery sees canopy surface, not wood mass, and clouds interrupt observation. Converting reflectance to carbon requires models, radar or lidar structure data, and field calibration.