المؤلفون: Faber, Marthe, Curtis, Andrew

المساهمون: National Research Fund, Natural Environment Research Council

المصدر: Geophysical Journal International ; volume 237, issue 3, page 1459-1489 ; ISSN 0956-540X 1365-246X

مصطلحات موضوعية: Geochemistry and Petrology, Geophysics

الوصف: SUMMARY Material density remains poorly constrained in seismic imaging problems, yet knowledge of density would provide important insight into physical material properties for the interpretation of subsurface structures. We test the sensitivity to subsurface density contrasts of spatial and temporal gradients of seismic ambient noise wavefields, using wave equation inversion (WEI), a form of seismic gradiometry. Synthetic results for 3-D acoustic media suggest that it is possible to estimate relative density structure with WEI by using a full acoustic formulation for wave propagation and gradiometry. We show that imposing a constant density assumption on the medium can be detrimental to subsurface seismic velocity images. By contrast, the full acoustic formulation allows us to estimate density as an additional material parameter, as well as to improve phase velocity estimates. In 3-D elastic media, severe approximations in the governing wave physics are necessary in order to invert for density using only an array of receivers on the Earth's free surface. It is then not straightforward to isolate the comparatively weak density signal from the influence of phase velocity using gradiometric WEI. However, by using receivers both at the surface and in the shallow subsurface we show that it is possible to estimate density using fully elastic volumetric WEI.

الإتاحة: https://doi.org/10.1093/gji/ggae097Test
https://academic.oup.com/gji/article-pdf/237/3/1459/57214926/ggae097.pdfTest

المؤلفون: Adler, Antonius, Apellaniz, David, Bornberg, Christina, Dandumont, Colin, Dhuicque, Océanne, Faber, Marthe, Kechagias, Sotirios, Lisi, Serena, Lundstedt, Viktor, Milasevicius, Martynas, Pagu, Ana, Vidal, Florian, Schreiber, Lukas, Smith, Jacob, Steinsvik, Sindre

المساهمون: BELSPO - SPP Politique scientifique - Service Public Fédéral de Programmation Politique scientifique, sponsor, ULiège - Université de Liège, sponsor

مصطلحات موضوعية: CubeSat, AlpbachSummerSchool, NanoSatellite, EarthMantle, ESA, Engineering, computing & technology :: Aerospace & aeronautics engineering, Ingénierie, informatique & technologie :: Ingénierie aérospatiale

جغرافية الموضوع: international

الوصف: RUBIKS (Reconstruction of Undercrust Behaviour with Interconnected (K)cube Satellites): a nanosatellite mission dedicated to analysing the mantle. With 8 CubeSats (6U) on two Cartwheel-helix orbits, it is proposed to take magnetic and gravity measurements of the Earth’s interior, in order to gain information on the electrical conductivity and density of the mantle, especially the lower mantle.

العلاقة: https://www.summerschoolalpbach.atTest; Alpbach Summer School 2019, Alpbach, Autriche (du 16 juillet 2019 au 25 juillet 2019)

الوصول الحر: https://orbi.uliege.be/handle/2268/239895Test

المؤلفون: Casini, Andrea E.M., Mittler, Petra, Cowley, Aidan, Schlüter, Lukas, Faber, Marthe, Fischer, Beate, von der Wiesche, Melanie, Maurer, Matthias

مصطلحات موضوعية: Zentrale Aufgaben, geo

الوصف: In view of the future missions to the Moon and in the framework of the Moon Village vision, the European Space Agency (ESA) and German Aerospace Centre (DLR) are increasingly focused on activities leading from LEO human spaceflight to planetary exploration. A new era of coordinated human and robotic exploration is expected to begin with the construction of the Lunar Orbital Platform-Gateway (LOP-G), which will lead to a return of humans to the lunar surface. In this context, the European Astronaut Centre (EAC) and DLR, co-situated in Cologne, Germany, are preparing themselves for future manned exploration by conducting Earth-based analogue and preparatory activities. We focus herein on LUNA a novel lunar analogue facility that is currently under development at the Cologne campus which will complement existing campus analogue facilities such as Environmental Habitat (:envihab) and the Neutral Buoyancy Facility (NBF). LUNA includes an artificial lunar analogue facility that consists of a hall-type structure containing a regolith testbed. A large volume regolith simulant, EAC-1, will be used to recreate facsimile of a lunar terrain, while illumination conditions can be varied to recreate different Moon conditions. Adjacent to the LUNA hall is the habitation module and Future Lunar EXploration Habitat (FLEXHab), hosting up to 4 crewmembers for 1-day missions, and providing direct access to LUNA. It is planned that the FLEXHab will utilize a stand-alone power system built around hydrogen technology (fuel cells, electrolyzer, batteries and photovoltaics) for its energy supply. Strong synergies can be built with current analogue facilities at DLR :envihab and the NBF. For example, the DLR :envihab provides an infrastructure in which astronauts can sleep, eat and work under environmentally controlled conditions, even possibly under isolation. Within the LUNA testbed, specific mission scenarios can be simulated for astronaut training, including testing of geological/seismic regolith characterization techniques, In Situ ...

العلاقة: https://elib.dlr.de/133874Test/

الإتاحة: https://elib.dlr.de/133874Test/

المؤلفون: Casini, Andrea E.M., Mittler, Petra, Cowley, Aidan, Schlüter, Lukas, Faber, Marthe, Fischer, Beate, von der Wiesche, Melanie, Maurer, Matthias

المساهمون: Elsevier, B.V.

مصطلحات موضوعية: Zentrale Aufgaben, Astronautentraining, EAC-Europäisches Astronauten-Trainingscenter

الوصف: In view of the future missions to the Moon and in the framework of the Moon Village vision, the European Space Agency (ESA) and the German Aerospace Centre (DLR) are increasingly focused on activities leading from LEO human spaceflight to planetary exploration. A new era of coordinated human and robotic exploration is expected to begin with the construction of the Lunar Orbital Platform-Gateway (LOP-G), which will lead to a return of humans to the lunar surface. In this context, the European Astronaut Centre (EAC) and DLR, co-situated in Cologne, Germany, are preparing themselves for future human exploration by conducting Earth-based analogue and preparatory activities. We focus herein on LUNA a novel lunar analogue facility that is currently under development at the Cologne campus which will complement existing campus analogue facilities such as Environmental Habitat (:envihab) and the Neutral Buoyancy Facility (NBF). LUNA includes an artificial lunar analogue facility that consists of a hall-type structure containing a regolith testbed. A large volume regolith simulant, EAC-1, will be used to recreate facsimile of a lunar terrain, while illumination conditions can be varied to recreate different Moon conditions. Adjacent to the LUNA hall is the habitation module and Future Lunar EXploration Habitat (FLEXHab), hosting up to 4 crewmembers for 1-day missions, and providing direct access to LUNA. It is planned that the FLEXHab will utilize the energy module, a stand-alone power system built around hydrogen technology (fuel cells, electrolyzer, batteries and photovoltaics) for its energy supply. Strong synergies can be built with current analogue facilities at DLR :envihab and the NBF. For example, the DLR :envihab provides an infrastructure in which astronauts can sleep, eat and work under environmentally controlled conditions, even possibly under isolation. Within the LUNA testbed, specific mission scenarios can be simulated for astronaut training, including testing of geological/seismic regolith characterization ...

العلاقة: Casini, Andrea E.M. und Mittler, Petra und Cowley, Aidan und Schlüter, Lukas und Faber, Marthe und Fischer, Beate und von der Wiesche, Melanie und Maurer, Matthias (2020) Lunar analogue facilities development at EAC: the LUNA project. Journal of Space Safety Engineering, 7 (4), Seiten 510-518. Elsevier. doi:10.1016/j.jsse.2020.05.002 . ISSN 2468-8967.

الإتاحة: https://doi.org/10.1016/j.jsse.2020.05.002Test
https://elib.dlr.de/136327Test/
https://www.sciencedirect.com/science/article/abs/pii/S2468896720300367Test