Sentinel-2

Sentinel-2
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Name	Sentinel-2
Mission type	Earth observation
Operator	European Space Agency
Manufacturer	Airbus Defence and Space
Launch mass	1,140 kg
Power	1,300 W
Launch date	2015–present
Orbit	Sun-synchronous orbit
Instruments	Multispectral Imager

Sentinel-2 Sentinel-2 is a European Space Agency Earth observation satellite program designed to provide high-resolution optical imagery for land and coastal monitoring. The program supports a range of users including national agencies, research institutions, environmental organizations, and commercial companies involved with Copernicus Programme, European Commission, European Space Agency, European Space Research and Technology Centre, European Union, and European Environment Agency. The mission complements other missions in the Copernicus Programme constellation, enabling monitoring from the Alps to the Amazon Rainforest and from the Mediterranean Sea to the Great Barrier Reef.

Overview

Sentinel-2 comprises a constellation of twin satellites built to deliver systematic, frequent, and multispectral imagery of terrestrial surfaces and coastal waters. The project involves industrial partners such as Airbus Defence and Space, Thales Alenia Space, and suppliers integrated under contracts with the European Space Agency and the European Commission. The program’s design draws on heritage from missions like SPOT and Landsat and complements radar missions such as Sentinel-1 and atmospheric missions such as Sentinel-5P. Data policies emphasize open access to support institutions including European Environment Agency, Food and Agriculture Organization, World Health Organization, and national agencies like National Aeronautics and Space Administration partners and research centers at University of Oxford and ETH Zurich.

Mission and Objectives

Primary objectives include mapping land cover, monitoring vegetation dynamics, supporting disaster management, and contributing to European Union policy needs for agriculture, forestry, and water management. Key mission goals support programs and initiatives such as the Common Agricultural Policy, Global Earth Observation System of Systems, United Nations Framework Convention on Climate Change, and Group on Earth Observations. Sentinel-2 provides continuity for long-term time series used by organizations like NASA, US Geological Survey, National Oceanic and Atmospheric Administration, Japan Aerospace Exploration Agency, and academic partners at Columbia University and University of California, Berkeley.

Spacecraft and Instrumentation

The spacecraft platforms were manufactured by Airbus Defence and Space with payloads developed by teams including Thales Alenia Space. Each satellite carries a Multispectral Instrument (MSI) with 13 spectral bands spanning visible, near-infrared, and shortwave infrared wavelengths. The instrument’s heritage links to sensors such as Landsat 8’s Operational Land Imager and to optical instruments flown on SPOT missions. Onboard avionics, attitude control, and thermal systems were developed with suppliers used in projects like Gaia and Copernicus Sentinel-3. The satellites operate in a sunsynchronous orbit optimized for repeat intervals that support missions run by agencies such as European Space Operations Centre and flight teams coordinated with the European Union.

Data Products and Processing

Sentinel-2 delivers Level-1C top-of-atmosphere reflectance and Level-2A surface reflectance products processed through the European Space Agency’s processing chains and toolboxes developed by groups at European Space Research and Technology Centre and partners including CNES and DLR. Data distributions integrate with platforms such as the Copernicus Open Access Hub, commercial cloud providers supporting projects from Microsoft Azure collaborations, and archives used by US Geological Survey and academic data centers at University of Colorado Boulder. The product suite enables indices like NDVI and BSI for users at Food and Agriculture Organization and International Union for Conservation of Nature workflows.

Applications and Use Cases

Sentinel-2 imagery is used extensively for agricultural monitoring by agencies implementing Common Agricultural Policy compliance checks, for forestry management in regions managed by Food and Agriculture Organization, and for urban mapping projects in cities like Paris, London, and Madrid. Environmental monitoring applications include coastal change studies around the Baltic Sea and reef assessments at locations such as the Great Barrier Reef. Disaster response teams from United Nations Office for the Coordination of Humanitarian Affairs and national civil protection agencies use rapid mapping to support earthquake and flood response scenarios similar to those managed in coordination with European Commission civil protection mechanisms. Scientific studies at institutions like Imperial College London, Max Planck Society, and Potsdam Institute for Climate Impact Research use Sentinel-2 time series for ecosystem and climate research.

Launches and Mission History

The first Sentinel-2 satellite was launched in 2015 by a Vega launcher from Guiana Space Centre; its twin followed in 2017, augmenting revisit frequency for global coverage. Mission operations have ties to European Space Operations Centre and data processing centers such as ESA ESRIN with international collaborations including data exchanges with NASA and US Geological Survey. Throughout the mission, upgrades in ground processing and calibration have been implemented drawing on methodologies used in Landsat reprocessing campaigns and cross-comparisons with missions like MODIS.

Challenges and Future Developments

Challenges include calibration stability, cloud screening accuracy in regions such as the Amazon Rainforest and Sahara Desert, and sustaining long-term continuity alongside successor missions planned by the European Commission and European Space Agency. Future developments include enhanced cloud computing distribution, integration with commercial constellations from companies like Planet Labs and partnerships resembling those between ESA and EUMETSAT, and potential technology upgrades influenced by research at European Organisation for Astronomical Research in the Southern Hemisphere and laboratories at CNES. Continued collaboration with global institutions such as Group on Earth Observations and United Nations Environment Programme will drive applications for climate monitoring and sustainable development goals led by entities including World Bank and United Nations Development Programme.

Category:Earth observation satellites Category:Copernicus Programme