A5042346114- Soil Moisture and Remote Sensing
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Cryospheric studies and observations
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Precipitation Measurement and Analysis
- Climate change and permafrost
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Spacecraft and Cryogenic Technologies
- Geophysical Methods and Applications
- Planetary Science and Exploration
- Antenna Design and Optimization
- Astronomical Observations and Instrumentation
- Arctic and Antarctic ice dynamics
- Scientific Research and Discoveries
Centre National d'Études Spatiales
2021-2024
Centre d'Études Spatiales de la Biosphère
2022
Institut de Recherche en Astrophysique et Planétologie
2017-2021
Centre National de la Recherche Scientifique
2016-2019
Université de Toulouse
2016-2019
Université Toulouse III - Paul Sabatier
2016-2017
We report the results of an extended spectropolarimetric and photometric monitoring weak-line T Tauri star TAP 26, carried out within MaTYSSE programme with ESPaDOnS spectropolarimeter at 3.6 m Canada-France-Hawaii Telescope. Applying Zeeman-Doppler Imaging to our observations, concentrating in 2015 November 2016 January spanning 72 d total, 16 13 January, we reconstruct surface brightness magnetic field maps for both epochs demonstrate that distributions exhibit temporal evolution not...
We report results of an extended spectropolarimetric and photometric monitoring the weak-line T Tauri star V830 Tau its recently-detected newborn close-in giant planet. Our observations, carried out within MaTYSSE programme, were spread over 91d, involved ESPaDOnS Narval spectropolarimeters linked to 3.6m Canada-France-Hawaii, 2m Bernard Lyot 8-m Gemini-North Telescopes. Using Zeeman-Doppler Imaging, we characterize surface brightness distributions, magnetic topologies differential rotation...
We report on observations of the active K2 dwarf $ε$ Eridani based contemporaneous SPIRou, NARVAL, and TESS data obtained over two months in late 2018, when activity star was reported to be a non-cyclic phase. first recover fundamental parameters target from both visible nIR spectral fitting. The large-scale magnetic field is investigated polarimetric data. From unpolarized spectra, we estimate total flux through Zeeman broadening magnetically sensitive lines chromospheric emission using...
We report the analysis, conducted as part of MaTYSSE programme, a spectropolarimetric monitoring ~0.8 Myr, ~1.4 MSun disc-less weak-line T Tauri star V410 Tau with ESPaDOnS instrument at Canada-France-Hawaii Telescope and NARVAL T\'elescope Bernard Lyot, between 2008 2016. With Zeeman-Doppler Imaging, we reconstruct surface brightness magnetic field Tau, show that is heavily spotted possesses ~550 G relatively toroidal field. find features weak level differential rotation equator pole ~5...
We report results of a spectropolarimetric and photometric monitoring the weak-line T Tauri star V410 Tau based on data collected mostly with SPIRou, near-infrared (NIR) spectropolarimeter recently installed at Canada-France-Hawaii Telescope, as part SPIRou Legacy Survey large programme, TESS between October December 2019. Using Zeeman-Doppler Imaging (ZDI), we obtained first maps photospheric brightness large-scale magnetic field surface this young derived from NIR data. For time, ZDI is...
Synthetic aperture interferometry (SAI) is a signal processing technique that mixes the signals collected by pairs of elementary antennas to obtain high-resolution images with aid computer. This note aims at studying effects distance between synthetic interferometer and an observed scene respect size antenna array onto imaging capabilities instrument. Far-field conditions near-field ones are compared from algebraic perspective simulations conducted microwave frequencies Microwave Imaging...
published or not.The documents may come from teaching and research institutions in France abroad, public private centers.L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de scientifiques niveau recherche, publiés ou non, émanant des établissements d'enseignement recherche français étrangers, laboratoires publics privés.
Abstract This conference paper reports the recent discoveries of two hot Jupiters (hJs) around weak-line T Tauri stars (wTTS) V830 Tau and TAP 26, through analysis spectropolarimetric data gathered within Magnetic Topologies Young Stars Survival massive close-in Exoplanets (MaTYSSE) observation programme. HJs are thought to form in outskirts protoplanetary discs, then migrate inwards close their host as a result either planet-disc type II migration or planet-planet scattering. Looking for...
For almost five years, phase 0 and A studies have been conducted by the French space agency for a second generation of Soil Moisture Ocean Salinity (SMOS) satellite devoted to High Resolution (HR) follow-on mission. Within frame preliminary results obtained with candidate array this SMOS-HR project, contribution focuses on what could happen any synthetic aperture imaging radiometer when shortest spacing between antennas interferometric becomes smaller than geometrical limit below which...
The Soil Moisture and Ocean Salinity (SMOS) satellite has provided, for the very first time, systematic passive L-band (1420 - 1427 MHz) measurements from space with a spatial resolution of ~40 Km. Preliminary results studies conducted within frame High Resolution (HR) follow-on mission are presented. SMOS-HR project undergone Phase 0 study by French agency. aim this contribution is to improve capabilities ~10 Km ~4 aid swarm nano-satellites orbiting close connected array selected SMOS-HR....
This paper reports on the main results of SMOS-HR instrument technical study, a new interferometric radiometer dedicated to Soil Moisture and Ocean Salinity measurement from space. The aims at providing enhanced spatial resolution with respect SMOS integrating robust RFI (RF Interference) mitigation technique. key performance requirements architecture features trade-offs are exposed in this paper.
A new approach based on deep-learning methods is presented for reconstructing L-band brightness temperature images from the inversion of interferometric data, namely complex visibilities here simulated observations Soil Moisture and Ocean Salinity (SMOS) radiometer.A specific Deep Neural Network (DNN) architecture composed a fully connected followed by contracting expansive path proposed to learn relationship between maps.The performances DNN are compared those algebraic inversions Fourier...
We wish to present the CNES contribution Sentinel-3 Next Generation - Topography (S3NG-T) project. In wake of SWOT mission, which pioneered use SAR interferometry for surface water altimetry, ESA is considering using this new approach successor its current operational mission (S3), S3NG. Such so-called “swath altimetry” enables access two-dimensional features on surfaces, much more directly than traditional Nadir altimetry (such as that used aboard S3)...
Digital Beam Forming (DBF) and Synthetic Aperture Inter-ferometry (SAI) are signal processing techniques that mixes the signals collected by an antenna array to produce high resolution images. This study aims at comparing these two approaches with aid of simulations conducted microwaves frequencies within frame Soil Moisture Ocean Salinity (SMOS) mission which is providing for more than a decade systematic passive L-band measurements from space. Although using same sharing goal, there few...
The Soil Moisture and Ocean Salinity (SMOS) satellite is performing systematic L-band observations since 2009, allowing a large number of science operational applications. Several recent studies have shown the need continuity observations, in particular with an increased angular resolution. In this contribution, two instrumental concepts are presented to reach native resolutions 5–10 km. addition, using airborne data, it also that accuracy downscaling coarser resolution data km high...
Recent applications of passive L-band observations from space are summarized for ocean, land surface and cryosphere applications. The main limitation the measurements performed by current generation sensors is spatial resolution. need a mission ensuring continuation with high resolution (10-15 km) discussed.
Within the framework of a phase A study for CNES SMOS-HR (Soil Moisture and Ocean Salinity High Resolution) mission, Airbus Defence Space has performed an architecture feasibility implementation correlator function. Due to very large number antennas relatively bandwidth, processing power matrix correlation is massive with more than 7500 GMAC per second. An in KU060 FPGA VERSAL ACAP VC1902 been performance metrics have analysed. For both implementations, bottlenecks identified optimised proposed.
In the framework of imaging by aperture synthesis, an alternative approach to algebraic inversions complex visibilities is discussed. This based on Deep Learning (DL) techniques. A database was computed using realistic L-band brightness temperature (BT) maps from SMOS interferometer and computing visibilities. The DL manages learn BT relationship. DL-reconstructed images show a lower error with respect original than those method. addition, DL-BTs do not any alias contamination, providing...