Sentinel-2 Mission Overview
The Sentinel-2 mission objectives are to provide:
- systematic global acquisitions of high-resolution, multispectral observations combined with a high revisit frequency
- continuity of multi-spectral imagery provided by SPOT-VGT and the United States Geological Survey (USGS) Landsat Thematic Mapper (TM) instrument
- observational data for the next operational products generation, such as land-cover maps, land-change detection maps and geophysical variables.
The Sentinel-2 mission consists of two polar-orbiting satellites (Sentinel-2A, launched 23 June 2015 and 2B, launched 7 March 2017) that are phased by 180o, ensuring observations per 5 days at the Equator and per 2-3 days at mid-latitudes. Sentinel-2 is an optical mission carrying the MultiSpectral Instrument (MSI) on-board, which is dedicated to land surface change observations (crop monitoring and management, vegetation and forest monitoring, etc.), land cover change monitoring, coastal zones observations, inland water and glacier monitoring, as well as ice extent and snow cover mapping.
MultiSpectral Imager (MSI)
The MSI has been designed based on land surface analysis requirements at high spatial and spectral resolution. MSI is a passive instrument, measuring reflected sunlight from the Earth’s surface in 13 spectral bands in the range 0.44 - 2.2 \(\mu\)m, with spatial nadir resolutions between 10 m and 60 m. A detailed overview of the spectral and spatial resolutions for which Terrascope provides data is given in Table 1.
Table 1: Sentinel-2 MSI spectral channels and their spatial resolutions.
Band | Center wavelength [\(\mu\)m] | spatial resolution [m] |
---|---|---|
B01 - Coastal aerosol | 0.443 | 60 |
B02 - Blue | 0.490 | 10 |
B03 - Green | 0.560 | 10 |
B04 - Red | 0.650 | 10 |
B05 - Vegetation red edge | 0.705 | 20 |
B06 - Vegetation red edge | 0.740 | 20 |
B07 - Vegetation red edge | 0.783 | 20 |
B08 - NIR | 0.842 | 10 |
B08a - Narrow NIR | 0.865 | 20 |
B11 - SWIR | 1.610 | 20 |
B12 - SWIR | 2.190 | 20 |