Articles for "Erdbeobachtung"

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Aeronautics | 25. November 2019 | posted by Johann Dauer

ALAADy symposium: Face-to-face with a new transport drone

ALAADy Symposium in Braunschweig
Image: DLR

Can low-cost drones capable of carrying as much weight as a pickup truck be built and operated cost-effectively? An interactive event format brought representatives from industry and humanitarian aid organisations and DLR researchers together to discuss this topic. A new technology demonstrator and almost four years of research results were presented at the Symposium on Automated Low-Altitude Air Delivery in Braunschweig. read more

Aeronautics | 08. November 2019 | posted by Georg Dietz

From idea to take-off – preparing for a HALO measurement flight

Credit: DLR (CC-BY 3.0)

No matter how many measurement flights we have already conducted, just before take-off the entire team assembles in front of the hangar and watches HALO's departure together. However, it takes days of planning and preparation to get to this point. For the SOUTHTRAC mission, all activities are carried out according to a fixed schedule, which is designed to ensure that flight preparations go as smoothly and efficiently as possible. Preparations for each flight take four days. As a measurement flight usually takes place every other day, several flights are always being planned at the same time, which is a complex task for everyone involved. At this point, I would like to present a timeline of the processes that have to take place before a measurement flight. read more

Space | 25. October 2019 | posted by Bernadette Jung

TerraSAR-X/TanDEM-X Science Meeting 2019: Monitoring very slow landslides from space


left image: ALOS-2 data (JAXA); centre image: modified Copernicus Sentinel data; right image: Terra-SAR-X data (DLR); prozessing each: by Gamma Remote Sensing and SUPSI

Loderio landslide (Switzerland): The colored dots mark the deformations over the course of a year. Three radar satellites and results in comparison: ALOS-2 PALSAR-2 data from 2014 to 2018 (left), Sentinel-1 data from 2014 to 2018 (center) and TerraSAR-X data from 2014 to 2017 (right). The data were processed using a special procedure called multi-temporal SAR interferometry.

Global change is no more a secret – neither is the annual TerraSAR-X and TanDEM-X Science Meeting at DLR Oberpfaffenhofen! High-level experts from all over the world presented the latest state of research from 21 to 24 October 2019 and point the way for future technologies in satellite-based remote sensing. Data source and mutual starting point are the two radar satellite missions TerraSAR-X and TanDEM-X. They provide indispensable data for environmental and climate research, for a better understanding of our earth. The applications are correspondingly diverse. The main research areas include forest, ocean, urbanization, ice cover, glacier, geohazards, agriculture, archaeology and technology development.

In the DLR-Blog we introduce some of the work presented at this year's science meeting. The short examples provided outline how the data of the German radar satellites support researchers worldwide

Over Switzerland, hazards due to slope instabilities affect about six percent of the territory. Particularly in the Alpine areas, landslides repeatedly lead to disasters. It is therefore of outstanding importance to continuously monitor the rate of movement of landslides for risk assessment and to survey their activity over time. Satellite SAR interferometry (InSAR) is one option for surface deformation monitoring over large areas. Recently, various nationwide maps of land deformation have thus been released in Norway, Germany and the United Kingdom. In Switzerland there is also high interest in creating deformation maps and time series of surface movement using InSAR.

Invisible danger

The very high spatial resolution of TerraSAR-X data allows for observing "invisible" or very slow landslides as shown in the latest research by Tazio Strozzi, Rafael Caduff and Andrea Manconi from Gamma Remote Sensing AG and Christian Ambrosi from the University of Applied Sciences and Arts of Southern Switzerland (SUPSI).

They report: Our work was based on large datastacks on the Loderio landslide of in the Canton of Ticino. The Loderio landslide is an example of a very slow but large and active landslide – with movements rates of a few centimeters per year. We used multi-temporal interferometric approaches to process the radar data. Thereby we obtained meaningful results for satellite-based monitoring of landslides in the Alps.

Sparse urbanization, large vegetated areas, snow cover, shadows and layover, atmospheric stratification and summer turbulences pose major challenges for InSAR processing. In particular, we investigated the potential and limitations of current satellite SAR data with different carrier frequencies (L-, C- and X-band), ground resolutions (around 10, 20 and 2 meters), time intervals (46, 6 and 11 days) and acquisition strategies (global versus on-demand, free versus commercial data) for operational monitoring of the Alps.

Our results show that the L-band has an advantage when it comes to temporal decorrelation over vegetated areas and relatively fast movements. The long-wave frequency range is less affected here than are the C- and X-bands. For this reason, the fastest moving part of the Loderio landslide could only be detected with PALSAR-2 data from the Japanese earth observation satellite ALOS-2. On the other hand, the C- and X-band are more sensitive to the very slow moving sectors of the landslide. Then TerraSAR-X data are preferred: they offer a high-precision spatial resolution, so we obtain a higher density of measurement points and are thus able to study local phenomena.

Space | 01. October 2019 | posted by Clemens Plank

SOFIA explores Europe’s night sky

Image: DLR (CC-BY 3.0)
Star guests – SOFIA will appear on ‘Sendung mit der Maus’ (‘Show with the mouse’) on 6 October.

At last, the airborne observatory SOFIA has returned to Germany! In the early hours of the morning on 16 September, the research aircraft landed safely at Stuttgart airport and was visited by about 2000 astronomy and aircraft enthusiasts over the following two days. On the third day, it took to the skies for its first scientific flight over Europe. read more

Space | 02. July 2019 | posted by Friederike Wütscher

AGBRESA - After the first lying down phase, preparations for the second campaign begin

Credit: DLR
One of the AGBRESA test participants completing the rehabilitation programme

The first campaign of the Artificial Gravity Bed Rest Study (AGBRESA) is over, the 12 test participants have moved out and all the utensils, beds, equipment and instruments have been checked and stored away. The majority of staff can now enjoy a breather before preparations begin in August for the second campaign, which will start early in the following month. Now, those involved have some time to draw conclusions from the first campaign. read more

Space | 07. June 2019 | posted by Eric Bershad

AGBRESA – Centrifuge rides against changes in astronauts’ vision

Image: DLR.
The team around Eric Bershad (second from left)

Participants in AGBRESA are on a long-duration mission to advance our understanding of the effects of spaceflight on the human body. During the AGBRESA mission, our team, Eric Bershad, Karina Marshall-Goebel and others, seek to understand how long-duration exposure to a six-degree head-down tilt, a spaceflight analogue, affects brain and eye health. read more

Space | 06. June 2019 | posted by Bed-rest-study

AGBRESA – A participant's tale: Reaching the finishing line through sheer will power

Credit: DLR (CC-BY 3.0)
The :envihab facility at the DLR site in Cologne

HDT 47. Forty-seventh day of bedrest. Another 13 days – and what's left of today. Yesterday I spoke with my wife on the phone. She still can't imagine what would possess a person to volunteer for 60 days in bed without even a pillow. “Do you never feel the urge to get up?” she asks. One of the support staff asked me a similar question just recently. With less than two weeks of bedrest left on the schedule it seems an apt time to answer this question. My summary is simple: it was exactly the way I imagined. read more

Space | 28. May 2019 | posted by Bed-rest-study

AGBRESA – terrestrial astronauts’ experiences of training on the centrifuge

Image: DLR.
The short-arm human centrifuge is a major component of the AGBRESA bed-rest study

The AGBRESA study is the first to explore using the DLR short-arm human centrifuge as a possible mitigation for the negative effects of weightlessness, which are being simulated by bed rest. This involves eight of the 12 terrestrial astronauts – the AGBRESA bedrest study participants – spinning in the centrifuge for 30 minutes every day. To allow them to experience artificial gravity they adopt a specific position – supine with heads pointed inwards – which exposes their feet to two g (twice Earth gravity) and the centre of gravity of their bodies to one g (Earth gravity).  This could become a training method for future long-term missions in space. By the end of their 60 days of bed rest, the participants will have spent 1800 minutes on the centrifuge and will have rotated 54,000 times!. read more

Space | 24. May 2019 | posted by Reinhold Ewald

Reinhold Ewald visits AGBRESA participants – from astronaut to explornaut

Image: DLR
From astronaut to explornaut – Reinhold Ewald visits the 12 AGBRESA bed-rest study participants.

The spaceship hatch is open, so pressure equalisation with the outside world has clearly already taken place. Standing before the :envihab facility in Cologne early on a Monday evening on my way to a special kind of ‘nauts’, namely ‘explornauts’, I feel as if I’m about to enter a space station. While Earth’s astronauts have not come much closer to their goal – the stars (astro-) – explornauts are in a comparatively better position. On the way to new inventions and discoveries, which explorers have always made, one does not always need impressive technology; sometimes a bed inclined down at the head end by six degrees is sufficient. read more

Space | 22. May 2019 | posted by Friederike Wütscher

AGBRESA: HyperCampus – How does artificial gravity affect plasticity of the brain?

Credit: DLR
Tests with the VR headset were conducted even before the bedrest period as part of the HyperCampus experiment by Alexander Stahn

"Do not disturb – Experiment ongoing!" is the message hanging from the door of participants' rooms during the AGBRESA studies. Often, a concession of scientists and medical staff march in and out of the participants' rooms – which are usually open – to administer various experiments – to transport them via gurney to the experiments in the nearby modules of the aerospace medicine research facility: envihab. read more