ESA - Sentinel-2 updates

[bolun]

First Sentinel-2B images delivered by laser

http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-2/First_Sentinel-2B_images_delivered_by_laser

With the Sentinel-2B satellite close to beginning its working life in orbit, this latest Copernicus satellite has linked up to Alphasat by laser, across almost 36 000 km of space, to deliver images of Earth just moments after they were captured.

The test, which was done as part of Sentinel-2B’s commissioning, included capturing a strip of images from Europe to North Africa and downlinking the data in just six minutes.

Credits: Copernicus Sentinel data (2017), processed by ESA

[bolun]

Happy birthday Sentinel-2A: Five Years of Environmental Insights

Sentinel-2A has orbited Earth more than 26,000 times – and travelled nearly 1.2 billion  kilometers in its quest to help us better understand and manage our environment. Since its launch on 23 June 2015 the Airbus-built Copernicus Sentinel-2A satellite has been delivering high-resolution optical imagery for many services and applications including agricultural and forestry management. Together with its twin satellite Sentinel-2B launched on 7 March 2017 the mission has become the most widely used of the whole Copernicus satellite family, with more than 60 percent of all Copernicus downloads coming from Sentinel-2 since the start of operations.

[jacqmans]

Mapping high-resolution methane emissions from space
14/12/2020

Scientists have used satellite data from the Copernicus Sentinel-2 mission, combined with the Sentinel-5P satellite, to detect individual methane emissions from space.

While carbon dioxide is more abundant in the atmosphere, and therefore more commonly associated with global warming, methane is more potent as a heat-trapping gas. It usually enters the atmosphere mainly from landfill sites, livestock farming, rice agriculture and the fossil fuel industry – particularly during coal, oil and gas extraction and transportation.   

Until recently, no straightforward solution has existed to detect individual methane emissions and track them back to their original sources. The Copernicus Sentinel-5P satellite, launched in 2017, is the first Copernicus mission dedicated to monitoring the atmosphere and is the first satellite to provide regular imagery of Earth for emission detection. However, the spatial resolution of its measurements limited the ability to correctly attribute methane emissions to their sources.

Now, scientists from Kayrros, a European technology start-up, have succeeded in developing a tool that can accurately detect individual methane emissions. By combining data from the Sentinel-5P satellite with measurements from the Copernicus Sentinel-2 infrared spectral range channels, scientists can now easily detect, quantify and attribute methane emissions to their sources.

This was first demonstrated during the summer of 2020, when a methane leak occurred in the Permian Basin – a major shale oil and gas production region in the United States. The leak was detected and quantified on 24 September 2020 by an aerial campaign commissioned by the Environmental Defense Fund, a leading international non-profit organisation.

Despite being detected, it was impossible to identify when the leak had started or the volume of methane released. The combination of Sentinel-2 and Sentinel-5P satellite data, with Kayrros technology, was used to identify the leak.

Antoine Rostand, President of Kayrros, said, “The results showed that the leak began on 4 July 2020, and that it had been detected 12 times between that date and its final disappearance on 26 September. Using proprietary quantification algorithms, we ascertained that these 12 quantifications ranged between five and 20 tonnes of methane per hour.”

Kayrros had previously detected other methane plumes over the same location during the summer, but this was the first clear spotting of the event using both Copernicus Sentinel-2 and Copernicus Sentinel-5P data in a synergistic way. 

“Using Copernicus Sentinel-2 images for methane hotspot detection is a major technical breakthrough as the satellite was not initially designed for this particular purpose,” commented Claus Zehner, ESA’s Copernicus Sentinel-5P Mission Manager. “This is important for methane monitoring efforts as the use of these data allows for the constant monitoring of oil and gas production areas around the world and will support the implementation of the recently released European Commission Methane strategy.”

https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-5P/Mapping_high-resolution_methane_emissions_from_space

[jacqmans]

Airbus completes integration of 3rd Copernicus Sentinel-2

Climate satellite will now undergo extensive testing

Friedrichshafen, 29 July 2021 – Airbus has finished the integration of the Copernicus Sentinel-2C satellite. It is the third of its kind and will now be shipped to Munich to undergo extensive environmental tests to prove its readiness for space. The test campaign will last until March 2022.

The data gathered by Sentinel-2 satellites are used for monitoring land use and changes, soil sealing, land management, agriculture, forestry, natural disasters (floods, forest fires, landslides and erosion) and to assist humanitarian aid missions. Environmental observation in coastal areas likewise forms part of these activities, as does glacier, ice and snow monitoring.

Offering "colour vision" for the Copernicus programme, Sentinel-2C – like its precursor satellites Sentinel-2A and -2B – will deliver optical images from the visible to short-wave infrared range of the electromagnetic spectrum. From an altitude of 786 kilometres, the 1.1 ton “C” satellite will enable continuation of imaging in 13 spectral bands with a resolution of 10, 20 or 60 metres and a uniquely large swath width of 290 km.

The telescope structure and the mirrors are made of silicon carbide, first pioneered by Airbus to provide very high optical stability and minimize thermo-elastic deformation, resulting in an excellent geometric image quality. This is unprecedented in this category of optical imagers. Each Sentinel-2 satellite collects 1.5 terabytes per day, after on-board compression. The data is formatted at high speed and temporarily stored on board in the highest capacity Mass Memory and Formatting unit currently flying in space. Data recording and laser-enabled downlink can take place simultaneously at high speed via the EDRS SpaceDataHighway, in addition to the direct X-band link to the ground stations.

The Sentinel-2-mission is based on a constellation of two identical satellites, Sentinel-2A (launched 2015) and Sentinel-2B (launched 2017), flying in the same orbit but 180° apart for optimal coverage and revisit time. The satellites orbit the Earth every 100 minutes covering all Earth’s land surfaces, large islands, inland and coastal waters every five days.

The Sentinel-2 satellites are currently sensing systematically all land and water areas, producing excellent results. Last year, the Sentinel-2 mission remained the top European mission in terms of peer-reviewed scientific publications (1200 during 2020) and data volume distributed to users.

The Sentinel-2 mission has been made possible thanks to the close collaboration between ESA, the European Commission, industry, service providers and data users. Its development has involved around 60 companies, led by Airbus Defence and Space in Germany for the satellites and Airbus Defence and Space in France for the multispectral instruments, while Airbus Defence and Space in Spain is responsible for the mechanical satellite structure.

Copernicus, Europe’s environmental monitoring programme, is led by the European Commission (EC) in partnership with the European Space Agency (ESA). The Copernicus Sentinels supply remote sensing data of the Earth, delivering key operational services related to environment and security.

[jacqmans]

Gearing up for third Sentinel-2 satellite
09/08/2021

With the first Copernicus Sentinel-2 satellite in orbit since 2015 and the second since 2017, engineers are busy preparing the mission’s follow-on pair to eventually pick up the baton to supply images for a myriad of applications from food security to monitoring the decline of Earth’s ice. Slated for launch at the beginning of 2024, Sentinel-2C has just started a punishing five-month testing programme to ensure that it is fit for its life in space.

The Sentinel-2 satellites each carry an innovative high-resolution multispectral imager, which combined with their 290 km-wide swath and frequent revisit times, offer unprecedented views of Earth.

The mission provides information mainly for agricultural practices and for tackling the global issue of food security. Images can be used to determine leaf area chlorophyll and water content indexes, for example. These data are particularly important for effective yield prediction and applications related to Earth’s vegetation.

However, over the last six years, the mission’s data have also been used to monitor changes in ice sheets and glaciers, coastal erosion, deforestation, burnt land resulting from wildfires, pollution in lakes and coastal waters, and more.

The mission is based on a constellation of two identical satellites in the same orbit, 180° apart for optimal coverage and data delivery. So, when Sentinel-2A retires, Sentinel-2C will be there to take its place, and eventually Sentinel-2D will replace Sentinel-2B.

This pairing guarantees the continuation of data delivery that many Copernicus Services users now rely.

With such an important career ahead, it is essential that the next Sentinel-2 satellite to launch, Sentinel-2C, is thoroughly tested. Engineers at Airbus Defence and Space in Friedrichshafen, Germany, have spent the last four months completing the build-up of the satellite by integrating its all-important multispectral imager instrument, and have now transported it to IABG’s facilities in Ottobrunn. Given the restrictions that the Covid pandemic has imposed this has been no easy matter.

Constantin Mavrocordatos, ESA’s Copernicus Sentinel-2 project manager said, “We are thrilled that Sentinel-2C is now ready to be fully tested. Airbus has done a spectacular job fitting the whole satellite out, especially during these difficult Covid times, which has led to some different ways of working to ensure all the restrictions are respected.

“The satellite arrived safely in IABG where it was unpacked, checked that all is well after its short road trip from Friedrichshafen and was installed in the cleanroom for series of exhaustive tests that will run until Christmas.”

The programme includes a range of mechanical tests that simulate the noise and vibrations of liftoff, tests that check that the satellite deploys its solar wing correctly, other tests that place the satellite under the extreme temperature swings it will experience in space, and electromagnetic compatibility tests to measure radio frequency radiation levels generated by the satellite and to verify the correct operation of the satellite equipment under this environment.

Once all this has been completed, Sentinel-2C will be transported back to Friedrichshafen for some final checks before being placed in storage to wait until it is time to ship it to the launch site in French Guiana. Liftoff is envisaged to take place in early 2024.

https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-2/Gearing_up_for_third_Sentinel-2_satellite

[FutureSpaceTourist]

https://www.airbus.com/en/newsroom/news/2023-03-three-sleeping-beauties-await-their-turn-in-orbit

Three ‘sleeping beauties’ await their turn in orbit

Copernicus Sentinel climate satellites 2C, 2D and 6B have been finalised and are being safely stored in special tents awaiting their turn in orbit. These tents meet very strict storage requirements, specifically long term accumulation of humidity and will ensure the satellites are kept clean until each is required to travel to its launch site.

The Sentinel satellites power Europe’s Copernicus programme, the world’s largest single programme for observing and monitoring the Earth. The first Copernicus Sentinel-2 satellite was launched in 2015 and the second in 2017, supplying images for a myriad of applications from food security to monitoring the shrinking ice caps, with the next pair (2C and 2D) set to follow when required.

Albert Zaglauer, head of Earth Observation Systems, says: “The work of Europe's Copernicus programme is vital. It monitors our planet’s health for the cost of just one cup of coffee per citizen per year.”

Sentinel-2C, is currently set for launch in 2024. The exact launch date will be decided by ESA and the European Union depending on several variables, one being the end of life of Sentinel-2A. Sentinel-2D is fully integrated and functionally tested. The next step will be the environmental test campaign, which will begin when more information is available about the launch date for Sentinel-2C and the end of life of Sentinel-2B.

The data gathered by Sentinel-2 satellites are used for monitoring land use and changes, soil sealing, land management, agriculture, forestry, natural disasters (floods, forest fires, landslides and erosion) and to assist humanitarian aid missions. Environmental observation in coastal areas likewise forms part of these activities, as does glacier, ice and snow monitoring. The telescope structure and the mirrors are made of silicon carbide, first pioneered by Airbus to provide very high optical stability and minimise thermo-elastic deformation, resulting in an excellent geometric image quality. This is unprecedented in this category of optical imagers.

Sentinel-6B, will continue the vital work of Sentinel-6A, launched in 2020 to monitor our oceans. The satellite, which includes European and US instruments, successfully completed its environmental test campaign last year. There is a second round of environmental tests foreseen before launch. ESA/NASA plan to launch Sentinel-6B in late 2025 and then to initiate a one-year handover with the first Sentinel-6A “Michael Freilich” satellite which has been successfully operating in orbit since the end of 2020.

The Copernicus Sentinel-6 will carry out high-precision measurements of ocean surface topography. Sentinel-6 measures its distance to the ocean surface with an accuracy of a few centimetres and uses this data to map it, repeating the cycle every 10 days, with the mission lasting up to seven years. It documents changes in sea-surface height, records and analyses variations in sea levels and observes ocean currents. Global sea levels are currently rising by an average of 3.3 millimetres a year as a result of global warming; this could potentially have dramatic consequences for countries with densely populated coastal areas.  Each satellite carries a radar altimeter, which works by measuring the time it takes for radar pulses to travel to the surface and back again to the satellite. Combined with precise satellite location data, altimetry measurements yield the height of the sea surface. The satellites’ instrument package also includes an advanced microwave radiometer that accounts for the amount of water vapour in the atmosphere, which affects the speed of the altimeter’s radar pulses.

Until they are called into action, the spacecraft will remain in hibernation, protected against any external disturbance.

Airbus has played a crucial role in constructing the satellites and instruments for Copernicus since the start of the programme in 1998, contributing its environmental expertise to all six Sentinel satellite missions and the new Copernicus next generation satellites: CRISTAL, LSTM, and ROSE-L missions.

Sentinel satellites are part of Copernicus, Europe’s environmental monitoring programme, which is led by the European Commission (EC) in partnership with the European Space Agency (ESA). The Copernicus Sentinels supply remote sensing data of the Earth, delivering key operational services related to environment and security.

For more information on the Copernicus satellites:

https://www.airbus.com/en/products-services/space/earth-observation/climate-missions

Photo caption:

Sentinels 2C, 2D and 6B climate satellites finalised and safely in hibernation

[Star One]

https://www.nationalgeographic.com/history/article/satellites-stone-walls-andes-trap

From the related paper:

Google Earth Engine was used to analyse the spatial distribution of above-ground vegetation in the Camarones Basin, based on Sentinel-2 satellite imagery from 2018 and 2021. These years were selected due to the availability of images with less than 10 per cent cloud cover that provided full coverage of the basin. The analysis focused on two key seasonal windows: the humid season following the summer rains (March–April) and the dry season (September–November). For both periods, the Modified Soil-Adjusted Vegetation Index (MSAVI) was calculated to estimate vegetation cover (Qi et al. Reference Qi, Chehbouni, Huete, Kerr and Sorooshian1994). MSAVI was selected over other commonly used vegetation indices due to the specific environmental characteristics of the study area. Above 2500masl, vegetation is predominantly shrubland within a semi-arid context, where extensive patches of bare soil are common. MSAVI is particularly suited to such conditions, as it mitigates distortions caused by exposed soils and high reflectance, reducing the likelihood of false vegetation readings (Zongfan et al. Reference Zongfan, Ling, Xuhai, Ming, Liangzhi, Huiqun and Jiaxin2022: 3). Seasonal variation in pasture coverage was identified by subtracting dry-season MSAVI values from those of the humid season (Figure 2). These differences were then analysed to assess whether seasonal variability in pasture availability potentially influenced the distribution of settlements and ungulate hunting traps. The resulting datasets were visualised and exported to ArcGIS Pro for further spatial analysis.

https://www.cambridge.org/core/journals/antiquity/article/tethered-hunting-and-mobility-landscape-in-the-andean-highlands-of-the-western-valleys-northern-chile/4CCE8CBE9047CA73697516FC9B19F0B2