Articles for "Earth observation"

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Space | 02. November 2023

What is new about the German radar satellites?

Die Mission TanDEM-X
Credit: DLR
The twin satellites TerraSAR-X and TanDEM-X fly in close formation – only a few hundred metres apart – and collect data for digital elevation models

Earth is a complex and dynamic system and radar remote sensing is designed to deliver quantitative 3D and 4D information about the planet's surface. The latest research results and information products obtained from high-resolution data acquired by the German satellites were presented during the TerraSAR-X and TanDEM-X Science Team Workshop, which was held at the German Aerospace Center from 18 to 20 October 2023. read more

Space | 24. October 2023

On Innovative Reference Targets and Analysis-Ready Radar Data

Dual-Band (L/X) Kalibrierungstransponder zur Unterstützung zukünftiger Satelliten-SAR-Missionen

World-leading experts for the calibration of spaceborne SAR systems met in Oberpfaffenhofen

Credit: DLR (CC BY-NC-ND 3.0)
(Top centered figure): Recently deployed innovative dual-band (L/X) calibration transponder to support future satellite SAR missions (detail)

How to define and ensure the data quality of state-of-the-art spaceborne radar satellites? How can synergies between various current and future radar missions be leveraged? How to ensure comparability between radar data acquired by missions operated by different national and international space agencies? And how can complex data sets acquired by different radar satellites be processed in such a way that they can be used by non-radar experts?

To discuss these and many other questions from the field of calibration of satellite radar missions, an international community of radar experts met at the Microwaves and Radar Institute of the German Aerospace Center (DLR) in Oberpfaffenhofen for the annual meeting of the CEOS WGCV SAR Subgroup on Calibration and Validation of High Resolution Synthetic Aperture Radar (SAR) Sensors. read more

Space | 22. March 2021 | posted by Manfred Gottwald

Using principles from painting – creating 3D-effect satellite images in true colour

Die physische Karte des Nördlinger Ries, abgeleitet aus einem farbkodierten, schräg beleuchteten digitalen Höhenmodell von TanDEM-X
Credit: © DLR
A physical map of the Nördlinger Ries, derived from a colour-coded, diagonally illuminated digital elevation model created using data acquired by TanDEM-X

How can an impression of three-dimensionality be created using a two-dimensional medium? In art, this question arose centuries ago. Certain painting techniques have since evolved to simulate effects of light and shadow, creating a 3D effect for the viewer. Such effects are referred to as trompe-l'œil – they 'deceive the eye'.

Earth observation satellites with multispectral sensors provide images in natural colours when their red, green and blue (RGB) channels are combined. However, they tend to appear somewhat 'flat'. To turn them into attractive, three-dimensional representations, they must first be 'transformed' into three dimensions. This can be achieved if we use proven methods from art as a guide in science, but this requires elevation information. read more

Space | 09. September 2020 | posted by Mattia Marconcini

World Settlement Footprint - Where do humans live?

Credit: DLR (CC-BY 3.0)
WSF2015 - Subset including India and vast part of Eastern and South Eastern Asia

After three years of meticulous data processing and comprehensive quality control, the World Settlement Footprint 2015 is now available. With a resolution of 10 metres, the new world map reveals settlement structures on Earth in 2015. read more

Space | 12. December 2018 | posted by Manfred Gottwald

TanDEM-X image of Hiawatha Glacier

Credit: DLR
TanDEM-X radar amplitude image of the region around Hiawatha Glacier. The apparent texture is due to the surface structure of the ice and its dynamics.

Glaciers abound on Greenland's coastline; fed by the Greenland ice sheet, they flow towards the Arctic Ocean. In the northwest, Hiawatha Glacier is located at 78.8 degrees north, 67 degrees west. It emerges from a semi-circular lobe at the ice sheet margin and forms a narrow tongue with a length of 10 kilometres extending onto the ice-free Inglefield Land. Hiawatha Glacier’s northern neighbour, the large Humboldt Glacier, is much more widely known. The front of the Humboldt Glacier is over 100 kilometres wide where it flows into the Nares Strait. The TanDEM-X image shows the region around Hiawatha Glacier.

Recently, however, Hiawatha Glacier has received worldwide attention. Some years ago, radar measurements performed as part of NASA’s Operation IceBridge, a campaign to monitor changes in the polar ice caps, revealed a circular depression in the ground underneath the ice where Hiawatha Glacier emerges from the ice sheet. Subsequent surveying by an international research team using a more advanced airborne radar system on board the Polar 6 aircraft operated by the Alfred Wegener Institute (AWI) yielded a more detailed view of that bowl-shaped feature. With a diameter of 31 kilometres and a depth of more than 300 metres, it resembles impact craters on Earth or the solid surface of other celestial bodies. read more

Space | 10. October 2017 | posted by Kathrin Höppner

Larsen C – A giant in motion

Credit: Copernicus data (2017) / ESA
Displacement of the iceberg at the Larsen-C ice shelf between July and October 2017

The A68 iceberg has been making headlines again after calving from the Larsen-C in July 2017. What happened? It moved and shrunk minimally. And while that may not be unusual, it is still worth a blog post.

Close examination of satellite image sequences from the last two months reveals the striking events unfolding there. Remember, the 5800 square kilometre iceberg is seven times the size of Berlin and is permanently moving. The iceberg has collided repeatedly with the ice shelf, dislodging smaller pieces of ice. read more

Space | 25. July 2017 | posted by Kathrin Höppner

Larsen C - TerraSAR-X observes calving of A-68 iceberg

Eisberg am Larsen-C-Schelfeis an der Antarktischen Halbinsel
Credit: DLR
After detaching: TSX-ScanSAR image from Saturday, 22 July 2017, 23:40 UTC

In recent days, the gigantic iceberg that has broken free of the Larsen C ice shelf on the Antarctic Peninsula has been in the headlines. Although the dislodging of icebergs from ice shelves is a natural occurrence and does indeed take place regularly in the Antarctic, as the media aptly reported, this event made a far larger impression than many others. Why is that? Probably because scientists have been using satellite data for months now to observe this region of the Antarctic in greater detail and have effectively been waiting for the event to occur. Moreover, the section of ice that dislodged this time is comparatively large, approximately seven times the size of Berlin. read more

Space | 19. October 2016 | posted by Simone Del Togno

How researchers use the latest Earth observation data – Part two

Credit: DLR/NASA GSFC/Lee
Elevation model of the mangrove forest region in the Sundarbans

In the second part of the series on the TerraSAR-X and TanDEM-X Science Meeting in Oberpfaffenhofen, we present further applications for satellite data. This time, for example, biomass is determined with the help of 'Earth observers from space'. Up until Thursday, 20 October 2016, international scientists will use the congress to show their research results on satellite-based Earth observation and to exchange ideas.

High above the swamp

Wet, warm and salty – the perfect habitat for mangroves. These tropical trees only feel at home in seawater or the brackish water of rivers. Together with other water-loving plants and shrubs, they can spread across entire forests or swamps. They offer protection against land loss through coastal erosion along seaboards and act as buffers to block storm surges and tsunamis. Around the world, mangrove forests account for an expanse of roughly 150,000 square kilometres. This equates to an enormous quantity of biomass – plant constituents that act as natural carbon reservoirs and that influence the climate. But exactly how much biomass is stored in these forests? And what about the inaccessible areas? read more

Space | 19. October 2016 | posted by Bernadette Jung

How researchers use the latest Earth observation data - Part one

KIOST inertial DEM
Quelle: DLR/KIOST/NASA GSFC
Elevation model of coastal area

Researchers from across the globe are in Oberpfaffenhofen for the TerraSAR-X and TanDEM-X Science Meeting. For four days, from 17 to 20 October 2016, they have the opportunity to present their results from the data acquired by the two Earth observation satellite missions and exchange information. Here, approximately 200 presentations give an overview of the latest research in satellite-based Earth observation. The radar data are used in various scientific fields, from climate research to geosciences to forestry, infrastructure planning and remote sensing methodology.

Covering the Science Meeting, the Space Blog presents some of the work presented. The short examples provided outline how the data of the German radar satellites support researchers worldwide. read more