Model of a Sentinel 2 satellite
|Operator||European Space Agency|
|Applications||Land and sea monitoring, natural disasters mapping, sea ice observations, ships detection|
|Design life||7 years|
|Launch mass||1,140 kg (2,513 lb)|
|Dry mass||1,016 kg (2,240 lb)|
|Dimensions||3.4 × 1.8 × 2.35 m (11.2 × 5.9 × 7.7 ft)|
|Maiden launch||Sentinel-2A |
23 June 2015
|Last launch||Sentinel-2B |
7 March 2017
Sentinel-2 is an Earth observation mission from the Copernicus Programme that systematically acquires optical imagery at high spatial resolution (10 m to 60 m) over land and coastal waters. The mission is a constellation with two twin satellites, Sentinel-2A and Sentinel-2B.
The mission supports a broad range of services and applications such as agricultural monitoring, emergencies management, land cover classification or water quality.
The Sentinel-2 mission has the following key characteristics:
To achieve frequent revisits and high mission availability, two identical Sentinel-2 satellites (Sentinel-2A and Sentinel-2B) operate together. The satellites are phased 180 degrees from each other on the same orbit. This allows for what would be a 10-day revisit cycle to be completed in 5 days. The 290km swath is created by the VNIR and SWIR, which are each made of 12 detectors that are lined in two offset rows. 
The orbit is Sun synchronous at 786 km (488 mi) altitude, 14.3 revolutions per day, with a 10:30 a.m. descending node. This local time was selected as a compromise between minimizing cloud cover and ensuring suitable Sun illumination. It is close to the Landsat local time and matches SPOT's, allowing the combination of Sentinel-2 data with historical images to build long-term time series.
The Sentinel-2 synthetic data and images generated therefrom are subject to an agreement between the ESA and the User, are laid out in a document entitled TERMS AND CONDITIONS FOR THE USE AND DISTRIBUTION OF SENTINEL DATA, which is a type of open access licence.
The Sentinel-2 satellites will each carry a single multi-spectral instrument (MSI) with 13 spectral channels in the visible/near infrared (VNIR) and short wave infrared spectral range (SWIR). Within the 13 bands, the 10 meter spatial resolution allows for continued collaboration with the SPOT-5 and Landsat-8 missions, with the core focus being land classification.
Designed and built by Airbus Defense and Space in France; this MSI imager uses a push-broom concept and its design has been driven by the large 290 km (180 mi) swath requirements, together with the high geometrical and spectral performance required of the measurements. It has a 150 mm (6 in) aperture and a three-mirror anastigmat design with a focal length of about 600 mm (24 in); the instantaneous field of view is about 21° by 3.5°. The mirrors are rectangular and made of silicon carbide, a similar technology to those on the Gaia mission. The system also employs a shutter mechanism preventing direct illumination of the instrument by the sun. This mechanism is also used in the calibration of the instrument. Out of all the different civic optical earth observation missions, Sentinel-2 is the first to have the ability to show three bands in the red edge.  The radiometric resolution is 12 bit with brightness intensity ranging from 0-4095. 
|Central wavelength (nm)||Bandwidth (nm)||Central wavelength (nm)||Bandwidth (nm)||Spatial resolution (m)|
|Band 1 – Coastal aerosol||442.7||21||442.2||21||60|
|Band 2 – Blue||492.4||66||492.1||66||10|
|Band 3 – Green||559.8||36||559.0||36||10|
|Band 4 – Red||664.6||31||664.9||31||10|
|Band 5 – Vegetation red edge||704.1||15||703.8||16||20|
|Band 6 – Vegetation red edge||740.5||15||739.1||15||20|
|Band 7 – Vegetation red edge||782.8||20||779.7||20||20|
|Band 8 – NIR||832.8||106||832.9||106||10|
|Band 8A – Narrow NIR||864.7||21||864.0||22||20|
|Band 9 – Water vapour||945.1||20||943.2||21||60|
|Band 10 – SWIR – Cirrus||1373.5||31||1376.9||30||60|
|Band 11 – SWIR||1613.7||91||1610.4||94||20|
|Band 12 – SWIR||2202.4||175||2185.7||185||20|
Due to the layout of the focal plane, spectral bands within the MSI instrument observe the surface at different times and vary between band pairs.
|Inter-band Pairs||Temporal Offset Between Bands|
|B08 / B02||0.264|
|B03 / B08||0.264|
|B03 / B02||0.527|
|B10 / B03||0.324|
|B10 / B02||0.851|
|B04 / B10||0.154|
|B04 / B02||1.005|
|B05 / B04||0.264|
|B05 / B02||1.269|
|B11 / B05||0.199|
|B11 / B02||1.468|
|B06 / B11||0.057|
|B06 / B02||1.525|
|B07 / B06||0.265|
|B07 / B02||1.790|
|B8a / B07||0.265|
|B8a / B02||2.055|
|B12 / B8a||0.030|
|B12 / B02||2.085|
|B01 / B12||0.229|
|B01 / B02||2.314|
|B09 / B01||0.271|
|B09 / B02||2.586|
Sentinel-2 will serve a wide range of applications related to Earth's land and coastal water.
The mission will provide information for agricultural and forestry practices and for helping manage food security. Satellite images will be used to determine various plant indices such as leaf area chlorophyll and water content indexes. This is particularly important for effective yield prediction and applications related to Earth's vegetation.
As well as monitoring plant growth, Sentinel-2 can be used to map changes in land cover and to monitor the world's forests. It will also provide information on pollution in lakes and coastal waters. Images of floods, volcanic eruptions  and landslides contribute to disaster mapping and help humanitarian relief efforts.
Examples for applications include:
The Sentinel Monitoring web application offers an easy way to observe and analyse land changes based on archived Sentinel-2 data.
The following two main products are generated by the mission:
Additionally, the following product for expert users is also available:
Examples of images taken.
Lake Mackay, Australia, by Copernicus Sentinel-2B
Central District, Botswana, by Copernicus Sentinel-2A
Vojvodina, Serbia, by Copernicus Sentinel-2A
Central-eastern Brazil, by Copernicus Sentinel-2A
Lake Balaton, Hungary
Timeline of the Bhadla Solar Park (India) development, the World's largest photovoltaic power plants cluster in 2020
|Wikimedia Commons has media related to Sentinel-2.|