Remote sensing for the monitoring and the management of the environment

Basée sur une excellence historique dans les domaines du traitement du signal et des images et s’appuyant sur des leaders institutionnels et industriels de l’aéronautique et de l’exploration spatiale (lancement de satellites, développement de capteurs...), la communauté française de télédétection est l’une des plus actives au monde. Accompagnant la création du Chapitre Français de la société IEEE Géoscience et Télédétection (IEEE Geoscience and Remote Sensing Society), ce numéro spécial vise à mettre en lumière des développements méthodologiques récents pour le traitement et l’analyse des signaux et images de télédétection pour la surveillance et la gestion de l’environnement. Ce thème est particulièrement d’actualité, d’une part parce que ces aspects sont au coeur des enjeux sociétaux du 21ème siècle, d’autre part parce que les capteurs actuels permettent désormais effectivement d’observer ces phénomènes avec précision, à moidre coût et sur une grande échelle. Néanmoins, la mise en correspondance des potentialités offertes par les nouveaux capteurs avec les applications envisagées nécessite des développements en traitement du signal. Les articles retenus pour ce numéro spécial s’inscrivent dans cette optique

Design of a dual species atom interferometer for space

Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species $^{85}$Rb/$^{87}$Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry, the detection unit, the vacuum system for $10^{-11}$ mbar ultra-high vacuum generation, and the high-suppression factor magnetic shielding as well as the thermal control system. The laser system is based on a hybrid approach using fiber-based telecom components and high-power laser diode technology and includes all laser sources for 2D-MOT, 3D-MOT, ODT, interferometry and detection. Manipulation and switching of the laser beams is carried out on an optical bench using Zerodur bonding technology. The instrument consists of 9 units with an overall mass of 221 kg, an average power consumption of 608 W (819 W peak), and a volume of 470 liters which would well fit on a satellite to be launched with a Soyuz rocket, as system studies have shown.Comment: 30 pages, 23 figures, accepted for publication in Experimental Astronom

STE-QUEST - Test of the Universality of Free Fall Using Cold Atom Interferometry

In this paper, we report about the results of the phase A mission study of the atom interferometer instrument covering the description of the main payload elements, the atomic source concept, and the systematic error sources

Cold atoms in space: community workshop summary and proposed road-map

We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies

Cold atoms in space: community workshop summary and proposed road-map

We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies.publishedVersio

Cold atoms in space: community workshop summary and proposed road-map

We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies

The Interferometric Cartwheel for ENVISAT

CNES and DLR have investigated the possibility of a formation flight of a cluster of passive radar micro-satellites with eth Envisat earth oberservation satellite. The mission goal is to achieve a Digital Elevation Model of the solid Earth of unequalled coverage and accuracy

Determination of ice flow velocity in Svalbard from ERS-1 interferometric observations (scientific paper)

Based on ERS-1 data recorded in autumn 1991,differential interferogrammes have allowed the determination of the ice flow of north-west Spitsbergen glaciers. The highest velocity of the d\u27Arodesbreen and the Fjortendejulibreen, observed in their equilibrium zone, was 3cm and 6.6cm per day, respectively. The large Kronebreen (700(km)^2) is fed by two plateaux, Isachsenfonna and Holtedahlfonna. Along the longitudinal axis of Isachsenfonna, the velocity was near constant, around 20cm per day over a distance of 20km, while the velocity on Holtedahlfonna increased from near zero in the higher basin to 52cm per day at 15km to the calving front. The obtained velocities were in excess of 48% of the annual average velocity measured by GPS at three locations. Interferometric pairs were obtained at the end of the ablation period when the presence of subglacial meltwater can still lead a high velocity. These relatively high rates of velocity indicate that the basal sliding of Isachsenfonna and Holtedahlfonna is important and that the glacier sole must be at the melting point down to the front. The present temperature distribution in the glacier is still possibly influenced by a surge, which occurred 130 years ago