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Messerotti M.,National institute for astrophysics | Messerotti M.,University of Trieste | Lilensten J.,Institute Of Planetologie Et Dastrophysique Of Grenoble Ipag | Calders S.,Belgian Institute for Space Aeronomy | And 2 more authors.
Journal of Space Weather and Space Climate

COST (European Cooperation in Science and Technology) is one of the longest-running European frameworks supporting cooperation among scientists and researchers across Europe. Its action ES0803 "Developing Space Weather Products and Services in Europe" involves the task "Exploitation, Dissemination, Education and Outreach". To meet the objectives of this task, we describe how we developed and maintained the Space Weather Portal, initiated the electronic Journal of Space Weather and Space Climate, took care of the scientific organization of the annual European Space Weather Week conference and of two schools for scientists and students from the space weather community. We also describe several dissemination projects supported by the action, which target the non-specialist in the field of space weather. © P. Vanlommel et al., Published by EDP Sciences 2014. Source

Doute S.,Institute Of Planetologie Et Dastrophysique Of Grenoble Ipag | Ceamanos X.,Meteo - France | Appere T.,CEA Saclay Nuclear Research Center
Planetary and Space Science

We propose a new method to retrieve the optical depth of Martian aerosols (AOD) from OMEGA and CRISM hyperspectral imagery at a reference wavelength of 1μm. Our method works even if the underlying surface is completely made of minerals, corresponding to a low contrast between surface and atmospheric dust, while being observed at a fixed geometry. Minimizing the effect of the surface reflectance properties on the AOD retrieval is the second principal asset of our method. The method is based on the parametrization of the radiative coupling between particles and gas determining, with local altimetry, acquisition geometry, and the meteorological situation, the absorption band depth of gaseous CO2. Because the last three factors can be predicted to some extent, we can define a new parameter β that expresses specifically the strength of the gas-aerosols coupling while directly depending on the AOD. Combining estimations of β and top of the atmosphere radiance values extracted from the observed spectra within the CO2 gas band at 2μm, we evaluate the AOD and the surface reflectance by radiative transfer inversion. One should note that practically β can be estimated for a large variety of mineral or icy surfaces with the exception of CO2 ice when its 2μm solid band is not sufficiently saturated. Validation of the proposed method shows that it is reliable if two conditions are fulfilled: (i) the observation conditions provide large incidence or/and emergence angles (ii) the aerosols are vertically well mixed in the atmosphere. Experiments conducted on OMEGA nadir looking observations as well as CRISM multi-angular acquisitions with incidence angles higher than 65 in the first case and 33 in the second case produce very satisfactory results. Finally in a companion paper the method is applied to monitoring atmospheric dust spring activity at high southern latitudes on Mars using OMEGA. © 2013 Elsevier Ltd. Source

Anugu N.,University of Porto | Garcia P.J.V.,University of Porto | Wieprecht E.,Max Planck Institute for Extraterrestrial Physics | Amorim A.,SIM Inc | And 8 more authors.
Proceedings of SPIE - The International Society for Optical Engineering

The acquisition camera for the GRAVITY/VLTI instrument implements four functions: a) field imager: science field imaging, tip-tilt; b) pupil tracker: telescope pupil lateral and longitudinal positions; c) pupil imager: telescope pupil imaging and d) aberration sensor: The VLTI beam higher order aberrations measurement. We present the dedicated algorithms that simulate the GRAVITY acquisition camera detector measurements considering the realistic imaging conditions, complemented by the pipeline used to extract the data. The data reduction procedure was tested with real aberrations at the VLTI lab and reconstructed back accurately. The acquisition camera software undertakes the measurements simultaneously for all four AT/UTs in 1 s. The measured parameters are updated in the instrument online database. The data reduction software uses the ESO Common Library for Image Processing (CLIP), integrated in to the ESO VLT software environment. © 2014 SPIE. Source

Veganzones M.A.,CNRS GIPSA Laboratory | Cohen J.,CNRS GIPSA Laboratory | Farias R.C.,CNRS GIPSA Laboratory | Marrero R.,CNRS GIPSA Laboratory | And 4 more authors.
2015 23rd European Signal Processing Conference, EUSIPCO 2015

Spectral unmixing is one of the most important and studied topics in hyperspectral image analysis. By means of spectral unmixing it is possible to decompose a hyperspectral image in its spectral components, the so-called endmembers, and their respective fractional spatial distributions, so-called abundance maps. New hyperspectral missions will allow to acquire hyperspectral images in new ways, for instance, in temporal series or in multi-angular acquisitions. Working with these incoming huge databases of multi-way hyperspec-tral images will raise new challenges to the hyperspectral community. Here, we propose the use of compression-based non-negative tensor canonical polyadic (CP) decompositions to analyze this kind of datasets. Furthermore, we show that the non-negative CP decomposition could be understood as a multi-linear spectral unmixing technique. We evaluate the proposed approach by means of Mars synthetic datasets built upon multi-angular in-lab hyperspectral acquisitions. © 2015 EURASIP. Source

Lilensten J.,Institute Of Planetologie Et Dastrophysique Of Grenoble Ipag | Coates A.J.,University College London | Dudok de Wit T.,LPC2E OSUC | Horne R.B.,British Antarctic Survey | And 4 more authors.
Astronomy and Astrophysics Review

Space weather has become a mature discipline for the Earth space environment. With increasing efforts in space exploration, it is becoming more and more necessary to understand the space environments of bodies other than Earth. This is the background for an emerging aspect of the space weather discipline: planetary space weather. In this article, we explore what characterizes planetary space weather, using some examples throughout the solar system. We consider energy sources and timescales, the characteristics of solar system objects and interaction processes. We discuss several developments of space weather interactions including the effects on planetary radiation belts, atmospheric escape, habitability and effects on space systems. We discuss future considerations and conclude that planetary space weather will be of increasing importance for future planetary missions. © 2014, The Author(s). Source

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