The first satellite in the European Space Agency's new Earth-monitoring Sentinel mission is already sending photos home. The first photos are of land use in Belgium, flooding in Namibia, and glacial retreat and land cover monitoring in Antarctica.
The first image from Sentinel-1A: land use around Brussels, Belgium. Image credit: ESA
Just nine days after launch, the new Sentinel satellite is up and capturing images. The very first image is a multispectral image captured in strip-mode. The wavelengths are mapped so that vegetation is green, and urban areas are red-blue, high-density urban areas (like Brussels and Antwerp harbour) are white, and waterways or other low-reflectivity areas like airport runways are black.
Radar image of the Zambezi River, including flooding on the Caprivi plain. Image credit: ESA
This 250-kilometer wide swath of radar data captures the extent of flooding on the Caprivi plain from the Zambezi River, and a peak at Victoria Falls farther east along the river. The radar image was acquired at 03:50 GMT, downloaded 2 hours later, processes and available less than an hour after that. While capturing particular locations still depends on the satellite being in the right place at the right time, the quick timeline from acquisition to release paired with the ability to take radar imagery in any weather conditions day or not illustrates the utility of Sentinel-1 for supporting disaster response.
Radar image of glacial retreat and iceberg calving in West Antarctica. Image credit: ESA
The Pine Island Glacier and Thwaites Glacier in West Antarctica are in irreversible retreat — this radar image of more calving icebergs is nothing new. However, the mission will be able to track how quickly these changes are happening, monitor sea ice extent, and track icebergs.
Differences in radar reflectivity of rock, ice, and water in Antarctica. Image credit: ESA
This norther transect of the Antarctica Peninsula uses dual polarization to detect how different materials reflect radar to different extents.
Sentinel-1A radar antenna undergoing frequency tests in an anechoic test chamber. Image credit: ESA
Sentinel-1 is the first of a series of six missions. Each mission serves a different function, and while robotic, none of them seems directly related to hunting mutants:
- Sentinel-1 is a pair of satellites with radar imaging systems in polar orbit, capable of all-weather measurements over land and ocean day or night. These satellites will help monitor sea-ice, oil spills, and ship detection, landslide-risk, and land use, and provide imagery for disaster response.
- Sentinel-2 is pair of satellites with a multispectral high-resolution imaging systems in polar orbit. They will effectively be Landsat-style satellites, used to track land use, vegetation stress, soil and water cover, or satellite imagery for emergency response.
- Sentinel-3 is a pair of satellites loaded with a variety of instruments to track topography, surface temperature, and colour. This data will support ocean forecasting systems, and environmental and climate monitoring.
- Sentinel-4 is an atmospheric monitoring payload that will be loaded onto a Meteosat Third Generation-Sounder (MTG-S) satellite in geostationary orbit.
- Sentinel-5 Precursor is an atmospheric monitoring mission still under development that will fill in the data-gap before Sentinel-5 makes it into orbit.
- Sentinel-5 is an atmospheric monitoring payload that will be loaded onto a MetOp Second Generation satellite in polar orbit.
- Sentinel-6 is a radar altimeter that will be used to measure global sea-surface height. The purpose is to provide data for operational oceanography and climate studies.
Sentinel-1A launched on 3 April 2014 on a Russian Soyuz rocket. Image credit: ESA
The launch of Sentinel-1A marks the first mission of the new Copernicus program. Copernicus is an Earth observation program, designed to provide accurate, timely, and accessible data to better understand our changing planet. The program incorporates the new Sentinels satellites, but also in-situ sensors on in the ground, sea, and air. The data are grouped into six thematic categories: land management, the marine environment, atmosphere, emergency response, security and climate change. The overall objective is to provide measurements for environmental management, tracking and mitigating the effects of climate change, and civil security for the European Union, and to contribute to the Global Earth Observation System of Systems (GEOSS).