ESA - Sentinel-1A updates

[jacqmans]

Press release, 27 August 2014

Sentinel-1 – Earth's topography as a coloured pattern


The radar system on board the European Space Agency (ESA) Sentinel-1A satellite has been imaging Earth's surface in 250-kilometre swathes since April 2014. Now, scientists at the German Aerospace Center (Deutsches Zentrum fuer Luft- und Raumfahrt;
DLR), working under a contract from ESA, have created the first interferogram from this data – showing the topography of Earth as a coloured pattern. The image shows the result of processing two data sets acquired over Corsica and Genoa on 7 and 19
August. "On the same day that the second acquisition was performed, we were able to produce this world-first interferogram and, in doing, so demonstrate the feasibility of this technology," says Richard Bamler, Director of the DLR Remote Sensing Technology
Institute. The aim of this development is the continuous monitoring of the movements of Earth's surface in the millimetre range.

Terrain Observation by Progressive Scans (TOPS) is the new acquisition mode that Sentinel-1 employs to continuously scan Earth in 250-kilometre swathes with a resolution of five metres perpendicular to and 20 metres along the flight direction. In future,
this technology will allow several Sentinel-1 satellites to regularly image Earth's entire landmass with an unprecedentedly short revisit interval. A great advantage of this type of sensor is that it can systematically image Earth unhindered by cloud
cover – both during day and night. The phase and polarisation information present in the images will be used for a wide range of applications such as producing up-to-date topographic maps, observing vegetation or measuring the movement of geologically
active regions from space with millimetre precision.

Large areas in short times

Numerous methods for the generation of interferograms have already been developed for the DLR-operated German radar satellite TerraSAR-X. "While TerraSAR-X delivers high-resolution images with the world’s best geometric accuracy, Sentinel-1 delivers
mid-resolution images – but with an enormous coverage," explains Bamler. Entire countries and continents can be mapped with the 250-kilometre-wide image swathes within days. "In a few years, time series will exist for every point on Earth, containing
valuable information for research into glaciers, ice sheets, oceans, volcanoes, earthquake zones and geological changes." Radar interferometry is often required for this research.

The demands placed by TOPS on interferometric processing are so high that, until now, only a few teams in the world have mastered it. At DLR’s Remote Sensing Technology Institute, an operational processor was developed for exactly this purpose under
contract from ESA. It was only once Sentinel-1A finally reached its final orbit, in which it returns to the same position after exactly 175 orbits or 12 days, that DLR scientists were able to generate an interferogram from two acquisitions taken over
the same area, but at different times. These results are an important contribution to the technical verification of the Sentinel 1 mission and have confirmed the satisfactory characteristics of the data to ESA and its users.

In future research projects, the Sentinel-1 and TerraSAR-X missions could complement each other. A deformation map showing subsidence and uplift over Germany is one possibility. "On detecting threatened areas with Sentinel-1, a more accurate analysis
with high-resolution TerraSAR-X data would follow." The high-precision elevation models of the TanDEM-X radar mission could also be used to geometrically correct Sentinel-1 interferograms.

[bolun]

Sentinel-1A spots potential oil slick from missing EgyptAir plane

20 May 2016

The Sentinel-1A radar satellite has detected a potential oil slick in the eastern Mediterranean Sea – in the same area where EgyptAir flight MS804 disappeared early yesterday morning on its way from Paris to Cairo.

The image was acquired by Sentinel-1A yesterday at 16:00 GMT (18:00 CEST).

ESA has given information related to the image to the relevant authorities to support the search operations.

http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-1/Sentinel-1A_spots_potential_oil_slick_from_missing_EgyptAir_plane

Credits: Copernicus Sentinel data [2016], processed by ESA & Sentinel-1 Mission Performance Centre

[bolun]

Sentinel-1A fragment impact in space

The picture shows Sentinel-1A’s solar array before and after the impact of a millimetre-size particle on the second panel. The damaged area has a diameter of about 40 cm, which is consistent on this structure with the impact of a fragment of less than 5 millimetres in size.

Related article: Copernicus Sentinel-1A satellite hit by space particle

http://www.esa.int/spaceinimages/Images/2016/08/Sentinel-1A_fragment_impact_in_space

Image credit: ESA

[bolun]

Larsen C breaks

Witnessed by the Copernicus Sentinel-1 mission on 12 July 2017, a lump of ice more than twice the size of Luxembourg has broken off the Larsen-C ice shelf, spawning one of the largest icebergs on record and changing the outline of the Antarctic Peninsula forever. The iceberg weighs more than a million million tonnes and contains almost as much water as Lake Ontario in North America. Since the ice shelf is already floating, this giant iceberg will not affect sea level. However, because ice shelves are connected to the glaciers and ice streams on the mainland and so play an important role in ‘buttressing’ the ice as it creeps seaward, effectively slowing the flow. If large portions of an ice shelf are removed by calving, the inflow of glaciers can speed up and contribute to sea-level rise. About 10% of the Larsen C shelf has now gone.

Read full story: Sentinel satellite captures birth of behemoth iceberg

http://www.esa.int/spaceinimages/Images/2017/07/Larsen_C_breaks

Image credit: contains modified Copernicus Sentinel data (2017), processed by ESA, CC BY-SA 3.0 IGO

[bolun]

Floods near Jacksonville

The Copernicus Sentinel-1 mission is being used to map floods resulting from Hurricane Florence. This map shows flooded areas in bright blue near Jacksonville, North Carolina, US, on 15 September 2018 at 11:07 GMT/UTC (07:07 local time).

Related article: Copernicus Sentinel maps Florence hurricane flood

https://www.esa.int/spaceinimages/Images/2018/09/Floods_near_Jacksonville

Image credit: contains modified Copernicus Sentinel data (2018)/Copernicus Emergency Management Service, processed by SERTIT

[Rondaz]

Data from @CopernicusEU #Sentinel-5P revealed that an explosion in a natural gas well in #Ohio in February 2018 released more than 50 000 tons of methane into the atmosphere, more than the oil and gas industries of most European nations do in a year..

https://twitter.com/esa/status/1207330347941289984

[bolun]

Suez Canal traffic jam seen from space

The enormous Ever Given container ship, wedged in Egypt’s Suez Canal, is visible in new images captured by the Copernicus Sentinel-1 mission.

The giant container ship ran aground in the canal on 23 March on its journey from China to the Netherlands. The image on the left, captured on 21 March, shows routine maritime traffic in the canal with vessels visible every 2 to 3 km. The image on the right, captured on 25 March, shows the 400 m-ship blocking the canal.

The canal connects Port Said on the Mediterranean Sea to the Indian Ocean via the Egyptian city of Suez on the Red Sea. The blockage has delayed hundreds of tankers and vessels in reaching their destination, and more maritime traffic is still heading to the crucial waterway. Ships can be seen accumulating in the Gulf of Suez.

Tug boats are working hard to dislodge the 200 000 tonne ship, however Egyptian authorities say it is unclear when the route will reopen.

The two identical Copernicus Sentinel-1 satellites carry radar instruments to provide an all-weather, day-and-night supply of imagery of Earth’s surface, making it ideal to monitor ship traffic.

The sea surface reflects the radar signal away from the satellite, and makes water appear dark in the image. This contrasts with metal objects, in this case the ships in the bay, which appear as bright dots in the dark waters.

https://www.esa.int/ESA_Multimedia/Images/2021/03/Suez_Canal_traffic_jam_seen_from_space

Image credit: Contains modified Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO

[jacqmans]

Sentinel-1 captures ground shift from Myanmar earthquake
24/04/2025

On 28 March 2025, a powerful magnitude 7.7 earthquake struck central Myanmar, sending shockwaves through the region. While the country is still dealing with the devasting aftermath, scientists have used radar images from the Copernicus Sentinel-1 satellites to reveal a detailed picture of how the ground shifted as a result of the quake – offering new insights into the mechanics of the tectonic Sagaing Fault and the scale of the seismic rupture.

Just one day before the earthquake struck, the Sentinel-1A satellite, as part of its routine global monitoring plan, captured a radar image of Myanmar. Then a few days after the quake, Sentinel-1C revisited the site, and was tasked to acquire an additional image. Both images were combined to form an interferogram of the Sagaing Fault.

The Sentinel-1 mission comprises two satellites that orbit 180 degrees apart so that together they cover the globe every six days.

The mission provides high-resolution radar imagery of Earth, regardless of weather conditions or if it is day or night to support a wide range of Copernicus services and applications. These include Arctic sea-ice monitoring, iceberg tracking and routine sea-ice mapping, as well as the detection of ground deformation caused by subsidence, uplift, landslides, and, as in this case, earthquakes.

Sentinel-1A has been in service since 2014, but Sentinel-1C has only been in orbit since December 2024 and is still in its commissioning phase – nevertheless it is already delivering on its promise.

While the immediate priority is to support recovery efforts and mourn the lives lost in this devastating disaster, understanding how the ground shifted is also crucial. Using satellite radar images, scientists can map the extent of ruptures and identify areas of increased seismic risk.

This information is vital for improving earthquake models and for developing effective disaster response strategies, including guiding safe and informed reconstruction, helping communities rebuild with greater resilience.

Thanks to the Sentinel-1 mission, the changing shape of Earth’s land surface can be mapped with millimetre precision, but it relies on a complex data processing method called synthetic aperture radar interferometry.

This involves combining two radar images, one from just before and one from just after the quake to produce an interferogram. By using tiny differences in the radar signal phase to detect ground shifts with incredible precision, the result is a colourful fringed pattern that reveals how the land moved during the earthquake.

What's more, the Sentinel-1 satellites’ advanced radar imaging mode, known as Terrain Observation with Progressive Scans, allows scientists to measure ground motion in both east–west and north–south directions – a unique capability. Most satellite imaging radars can only see across their flight path, but thanks to a technique called ‘burst overlap interferometry’, the Sentinel-1 mission offers a full view of the ground deformation.

Sentinel-1 radar image compared to interferogram

The first set of images, featured above, compares a radar image with an interferogram. The image on the left is a radar image captured by Sentinel-1C on 2 April, while the image on the right is an interferogram – a composite created by combining a Sentinel-1A image from 27 March with the Sentinel-1C image from 2 April, after the earthquake.

These images effectively zoom-in to an area around Pyawbwe, but the closer fringes indicate very clearly the notorious Sagaing Fault, which runs north–south as well as the ground shifts caused by the earthquake.

Each full cycle of colour, from cyan to yellow to red to blue and back to cyan, represents ground displacement of about 160 cm along the fault line. Across the fault line, each colour cycle represents ground displacement of about 28 mm. These impressive fringes show how different parts of the ground moved, with each side of the fault shifting in opposite directions – clear evidence of a tectonic slip.

Myanmar interferogram from Copernicus Sentinel-1

Then, this second set of images offers a wider view of the interferogram (left), where the tight fringes on the right cut through Mandalay and extend southwards, making the extent of the rupture clearly evident.

The image on the right uses data from Sentinel-1A and Sentinel-1C to reveal a ‘coherence map’, where the fault appears as a dark fracture slicing through the land. This coherence map shows areas that have changed between the two acquisition dates as dark tones while stable areas appear bright.

“We’re thrilled with the clarity of the results,” said the team from the DLR German Aerospace Center’s Microwave & Radar Institute, who processed and analysed the data.

These high-resolution radar images are not just impressive visuals, they're critical tools for earthquake science. By studying the fringes and phase jumps in the interferogram, geoscientists can create detailed ground deformation maps, helping to unravel how and where quakes change the surface. This information is vital for understanding seismic activity and preparing for future events.

“These data are a game-changer,” said ESA’s Sentinel-1 System Manager, Dirk Geudtner. “They enable faster, more accurate assessments after disasters, and helps us to improve earthquake models globally. This is a textbook example of how space technology helps us understand seismic hazards.”

ESA’s Sentinel-1 Project Manager, Ramón Torres, said, “These results demonstrate that the new Sentinel-1C satellite is working perfectly and its data can be used with confidence alongside its older Sentinel-1A sibling.”

https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-1/Sentinel-1_captures_ground_shift_from_Myanmar_earthquake#msdynmkt_trackingcontext=2a201074-357e-4dc2-87bc-40128a540200

[jacqmans]

Antarctic glacier caught stealing ice from neighbour
08/05/2025

Thanks largely to Copernicus Sentinel-1, scientists have discovered that a glacier in Antarctica is rapidly siphoning ice from neighbouring flows – at a pace never before seen. Until now, researchers believed that this process of ‘ice piracy’ in Antarctica took hundreds or even thousands of years, but these latest findings clearly demonstrate that this isn’t always the case.

Published today in The Cryosphere, the research, partly funded by the Science for Society element of ESA’s FutureEO programme, reveals that the fast-flowing Kohler East Glacier in West Antarctica has been stealing ice from a slower-moving neighbour.

Kohler Glacier, as well as the Pope and Smith Glaciers, are among the fastest-changing in West Antarctica, with some moving and thinning faster than others. These glaciers are situated upstream of the Dotson and Crosson Ice Shelves.

Ice from the Pope, Smith and Kohler Glaciers flows into the Dotson and Crosson Ice Shelves, which float on the Amundsen Sea. The rate at which the ice flows and  eventual melts into the sea has implications for sea-level rise.


https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-1/Antarctic_glacier_caught_stealing_ice_from_neighbour#msdynmkt_trackingcontext=c53001a3-f270-4d2c-b2fc-de7ed8a20300