ESA’s Sentinel Data

European Space Agency (ESA)

2014

The Sentinel satellite constellation provides Earth observation data under the Copernicus program, offering free and open access to a wide range of environmental information. The data covers various spectral, spatial, and temporal scales, enabling applications in environmental monitoring, land-use change, climate research, disaster management, and ocean observation. Sentinel-1 is equipped with C-band Synthetic Aperture Radar (SAR) that provides all-weather, day-and-night radar imagery, making it particularly useful for monitoring land and ocean surfaces, including applications like mapping, forestry, soil moisture estimation, and sea-ice observations. Sentinel-2 features a multispectral optical sensor capturing 13 spectral bands, offering high-resolution imagery (up to 10 meters), which is ideal for land cover classification, agricultural monitoring, and disaster management. Sentinel-3 carries multiple instruments to measure sea-surface topography, sea and land surface temperature, and ocean and land color, supporting ocean forecasting, environmental and climate monitoring, and land-use change detection. The data volume varies depending on the specific mission and product type. Sentinel-1 data files range from 1 GB to 6 GB per scene, depending on the observation mode and product type. Sentinel-2 Level-1C products, which cover a 100x100 km area, range from approximately 500 MB to 1 GB. Sentinel-3 product sizes vary widely depending on the instrument and processing level, ranging from several megabytes to over a gigabyte per product. The number of observations is continually increasing as the satellites remain operational and continuously capture data. Sentinel-1 revisits each region every 6 to 12 days, depending on the observation mode. Sentinel-2 provides global coverage of land surfaces every 5 days with its two satellites, Sentinel-2A and Sentinel-2B. Sentinel-3 offers a near-daily revisit for optical instruments, with shorter revisit times for altimetry measurements. Sentinel-1A was launched in April 2014, followed by Sentinel-1B in April 2016, and Sentinel-1C in December 2024. Sentinel-2A was launched in June 2015, Sentinel-2B in March 2017, and Sentinel-2C in September 2024. Sentinel-3A was launched in February 2016, and Sentinel-3B followed in April 2018.