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| Registros recuperados: 58 | |
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| Quilfen, Yves; Prigent, C; Chapron, Bertrand; Mouche, Alexis; Houti, N. |
| The physics of remote sensing sea surface measurements is still poorly understood under severe weather conditions. Wind vector algorithms are usually developed for non-precipitating atmospheres and for wind speeds less than 20 m/s. In this study, we analyze observations from the QuikSCAT Ku-band scatterometer collocated with the WindSat full polarimetric microwave radiometer to estimate the potential of these two instruments for sea surface wind retrieval under severe weather conditions. The Jason altimeter provides independent measurements of wind speed and rain rate for comparison purposes. The sensitivity of the radar cross-sections and brightness temperatures to the wind speed and direction is directly studied from the observations and compared with... |
| Tipo: Text |
Palavras-chave: Winds; Scatterometer; Radiometer. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-6393.pdf |
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| Gommenginger, Christine; Chapron, Bertrand; Hogg, Andy; Buckingham, Christian; Fox-kemper, Baylor; Eriksson, Leif; Soulat, Francois; Ubelmann, Clément; Ocampo-torres, Francisco; Nardelli, Bruno Buongiorno; Griffin, David; Lopez-dekker, Paco; Knudsen, Per; Andersen, Ole; Stenseng, Lars; Stapleton, Neil; Perrie, William; Violante-carvalho, Nelson; Schulz-stellenfleth, Johannes; Woolf, David; Isern-fontanet, Jordi; Ardhuin, Fabrice; Klein, Patrice; Mouche, Alexis; Pascual, Ananda; Capet, Xavier; Hauser, Daniele; Stoffelen, Ad; Morrow, Rosemary; Aouf, Lotfi; Breivik, Øyvind; Fu, Lee-lueng; Johannessen, Johnny A.; Aksenov, Yevgeny; Bricheno, Lucy; Hirschi, Joel; Martin, Adrien Ch; Martin, Adiran P; Nurser, George; Polton, Jeff; Wolf, Judith; Johnsen, Harald; Soloviev, Alexander; Jacobs, Gregg A.; Collard, Fabrice; Groom, Steve; Kudryavtsev, Vladimir; Wilkin, John; Navarro, Victor; Babanin, Alex; Martin, Matthew; Siddorn, John; Saulter, Andrew; Rippeth, Tom; Emery, Bill; Maximenko, Nikolai; Romeiser, Roland; Graber, Hans; Azcarate, Aida Alvera; Hughes, Chris W.; Vandemark, Doug; Silva, Jose Da; Leeuwen, Peter Jan Van; Naveira-garabato, Alberto; Gemmrich, Johannes; Mahadevan, Amala; Marquez, Jose; Munro, Yvonne; Doody, Sam; Burbidge, Geoff. |
| High-resolution satellite images of ocean color and sea surface temperature reveal an abundance of ocean fronts, vortices and filaments at scales below 10 km but measurements of ocean surface dynamics at these scales are rare. There is increasing recognition of the role played by small scale ocean processes in ocean-atmosphere coupling, upper-ocean mixing and ocean vertical transports, with advanced numerical models and in situ observations highlighting fundamental changes in dynamics when scales reach 1 km. Numerous scientific publications highlight the global impact of small oceanic scales on marine ecosystems, operational forecasts and long-term climate projections through strong ageostrophic circulations, large vertical ocean velocities and mixed layer... |
| Tipo: Text |
Palavras-chave: Satellite; Air sea interactions; Upper ocean dynamics; Submesoscale; Coastal; Marginal ice zone; Radar; Along-track interferometry. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00510/62121/66325.pdf |
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| Mouche, Alexis; Collard, Fabrice; Chapron, Bertrand; Dagestad, Knut-frode; Guitton, Gilles; Johannessen, Johnny A.; Kerbaol, Vincent; Hansen, Morten Wergeland. |
| The synthetic aperture radar (SAR) Doppler centroid has been used to estimate the scatter line-of-sight radar velocity. In weak to moderate ocean surface current environment, the SAR Doppler centroid is dominated by the directionality and strength of wave-induced ocean surface displacements. In this paper, we show how this sea state signature can be used to improve surface wind retrieval from SAR. Doppler shifts of C-band radar return signals from the ocean are thoroughly investigated by colocating wind measurements from the ASCAT scatterometer with Doppler centroid anomalies retrieved from Envisat ASAR. An empirical geophysical model function (CDOP) is derived, predicting Doppler shifts at both VV and HH polarization as function of wind speed, radar... |
| Tipo: Text |
Palavras-chave: Doppler; Surface wind; Synthetic aperture radar (SAR). |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19896/17554.pdf |
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| Nouguier, Frederic; Mouche, Alexis; Rascle, Nicolas; Chapron, Bertrand; Vandemark, Douglas. |
| Global colocalized ocean surface measurements using the Global Precipitation Measurement near-nadir dual-frequency Ku- and Ka-band microwave measurements are analyzed and compared. Focusing on the Ka and Ku cross-sections fall-off with incidence angles, the contemporaneous measurements enable to more precisely document differing ocean scattering characteristics for both microwave frequencies. Sensitivity with wind speed and significant wave height is further reported using global comparisons with numerical estimates. As demonstrated, the bifrequency capability can provide direct means to efficiently separate short-scale wave contributions, between mean squared slope and curvature characteristics, and to further gain valuable insights concerning near-nadir... |
| Tipo: Text |
Palavras-chave: Microwave; Radar cross section; Scattering; Spaceborne radar. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00352/46334/47128.pdf |
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| Hauser, D.; Caudal, G.; Guimbard, Sebastien; Mouche, Alexis. |
| Radar observations of the sea surface at C-Band and small incidence angles are used to investigate some properties of the surface slope probability density function (pdf). The method is based on the analysis of the variation of the radar cross-section with incidence angle, assuming a backscattering process following the Geometrical Optics theory. First, we assess the limit of this model in our experimental configuration by using simulations of radar cross-sections with a more accurate backscattering model, namely the Physical Optics model. We show that roughness properties with scales larger than 12 cm can be analyzed in our configuration (C-Band, incidence 7 to 16 degrees). The radar data are then analyzed in terms of filtered mean square slope under the... |
| Tipo: Text |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00000/11028/33570.pdf |
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| Jang, Jae-cheol; Park, Kyung-ae; Mouche, Alexis; Chapron, Bertrand; Lee, Ji-hyun. |
| In this study, using in situ measurements at 17 buoy stations off the Korean Peninsula, C-band model (CMOD) functions for Sentinel-1A/B IW mode synthetic aperture radar (SAR) data were validated. In total, 395 Sentinel-1A/B IW mode dual-vertical polarized images were used for collocation with in situ measurements from May 1, 2015, to September 30, 2017, and 807 matchup points were obtained. Prior to the validation, preprocessing such as speckle noise reduction and ship and land masking was completed. The in situ wind speeds were converted to a 10-m neutral wind considering atmospheric stability. High-resolution wind speeds were estimated by using the CMOD functions such as CMOD4, CMOD_IFR2, CMOD5, CMOD5.N, and CMOD5.Na. The root-mean-square errors of... |
| Tipo: Text |
Palavras-chave: C-band model (CMOD) functions; Synthetic aperture radar (SAR); Sentinel-1A/B; Wind speed; Wind speed error. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62395/66792.pdf |
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| Tenerelli, Joseph; Reul, Nicolas; Mouche, Alexis; Chapron, Bertrand. |
| The "galactic glitter" phenomenon at L-band, i.e., the scattering of celestial sky radiation by the rough ocean surface, is examined here as a potential source of error for sea surface salinity (SSS) remote sensing. We begin by considering the transformations that must be applied to downwelling celestial noise in order to compute the eventual impact on the antenna temperature. Then, outside the context of any particular measurement system, we use approximate scattering models along with a model for the equilibrium wind wave spectrum to examine how the scattered signal at the surface might depend on the geophysical conditions and scattering geometry. It is found that, when the specular point lies far away from the galactic plane, where the incident... |
| Tipo: Text |
Palavras-chave: Scattering; Remote sensing; Radiometry. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3922.pdf |
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| Stoffelen, Ad; Aaboe, Signe; Calvet, Jean-christophe; Cotton, James; De Chiara, Giovanna; Saldana, Julia Figa; Mouche, Alexis; Portabella, Marcos; Scipal, Klaus; Wagner, Wolfgang. |
| The second-generation exploitation of meteorological satellite polar system (EPS-SG) C-band-wavelength scatterometer instrument (called SCA), planned for launch in 2022, has a direct heritage from the successful advanced scatterometer (ASCAT) flown on the current EPS satellites. In addition, SCA will represent three major innovations with respect to ASCAT, namely: 1) Cross polarization and horizontal copolarization; 2) a nominal spatial resolution of 25 km; and 3) 20% greater spatial coverage than ASCAT. The associated expected science and application benefits that led the SCA design are discussed with respect to ocean, land, and sea ice applications for near-real time, climate monitoring, and research purposes. Moreover, an option to implement an ocean... |
| Tipo: Text |
Palavras-chave: Eddy currents; Radar signal processing; Sea ice; Soil measurements; Storms; Wind. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00386/49774/50320.pdf |
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| Bourassa, Mark A.; Meissner, Thomas; Cerovecki, Ivana; Chang, Paul S.; Dong, Xiaolong; De Chiara, Giovanna; Donlon, Craig; Dukhovskoy, Dmitry S.; Elya, Jocelyn; Fore, Alexander; Fewings, Melanie R.; Foster, Ralph C.; Gille, Sarah T.; Haus, Brian K.; Hristova-veleva, Svetla; Holbach, Heather M.; Jelenak, Zorana; Knaff, John A.; Kranz, Sven A.; Manaster, Andrew; Mazloff, Matthew; Mears, Carl; Mouche, Alexis; Portabella, Marcos; Reul, Nicolas; Ricciardulli, Lucrezia; Rodriguez, Ernesto; Sampson, Charles; Solis, Daniel; Stoffelen, Ad; Stukel, Michael R.; Stiles, Bryan; Weissman, David; Wentz, Frank. |
| Strengths and weakness of remotely sensed winds are discussed, along with the current capabilities for remotely sensing winds and stress. Future missions are briefly mentioned. The observational needs for a wide range of wind and stress applications are provided. These needs strongly support a short list of desired capabilities of future missions and constellations. |
| Tipo: Text |
Palavras-chave: Satellite; Wind; Stress; Ocean; Requirements. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62312/66565.pdf |
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| Hasager, Charlotte B.; Mouche, Alexis; Badger, Merete; Bingol, Ferhat; Karagali, Ioanna; Driesenaar, Tilly; Stoffelen, Ad; Pena, Alfredo; Longepe, Nicolas. |
| The offshore wind climatology in the Northern European seas is analysed from ten years of Envisat synthetic aperture radar (SAR) images using a total of 9256 scenes, ten years of QuikSCAT and two years of ASCAT gridded ocean surface vector wind products and high-quality wind observations from four meteorological masts in the North Sea. The traditional method for assessment of the wind resource for wind energy application is through analysis of wind speed and wind direction observed during one or more years at a meteorological mast equipped with well-calibrated anemometers at several levels. The cost of such measurements is very high and therefore they are only sparsely available. An alternative method is the application of satellite remote sensing.... |
| Tipo: Text |
Palavras-chave: Offshore wind; SAR; QuikSCAT; ASCAT; Wind energy; Resource; Northern Europe. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00239/35007/33542.pdf |
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| Sapp, Joseph W.; Mouche, Alexis; Jelenak, Zorana; Chang, Paul S.; Frasier, Stephen J.. |
| In Winter 2017, the University of Massachusetts Amherst's Imaging Wind and Rain Airborne Profiler (IWRAP) was flown on a National Oceanic and Atmospheric Administration (NOAA) WP-3D Hurricane Hunter aircraft under the direction of scientists from Center for Satellite Applications and Research (STAR) at NOAA/National Environmental Satellite, Data, and Information Service (NESDIS) over the North Atlantic ocean out of Shannon, Ireland. IWRAP is a dual-frequency, conically scanning, profiling Doppler radar initially developed by Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts Amherst that is routinely installed on the NOAA WP-3D research aircraft. The flight on February 6, 2017, targeted a region of high winds (greater than 30... |
| Tipo: Text |
Palavras-chave: Satellites; Aircraft; Spaceborne radar; Synthetic aperture radar; Sea measurements; Wind speed; C-band; Cross polarization; Normalized radar cross section (NRCS); Ocean winds; Scatterometry. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00640/75251/75648.pdf |
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| Hasager, C. B.; Vincent, P.; Husson, Romain; Mouche, Alexis; Badger, M.; Pena, A.; Volker, P.; Badger, J.; Di Bella, A.; Palomares, A.; Cantero, E.; Correia, P. M. F.. |
| The aim of the paper is to present offshore wind farm wake observed from satellite Synthetic Aperture Radar (SAR) wind fields from RADARSAT-1/-2 and Envisat and to compare these wakes qualitatively to wind farm wake model results. From some satellite SAR wind maps very long wakes are observed. These extend several tens of kilometres downwind e.g. 70 km. Other SAR wind maps show near-field fine scale details of wake behind rows of turbines. The satellite SAR wind farm wake cases are modelled by different wind farm wake models including the PARK microscale model, the Weather Research and Forecasting (WRF) model in high resolution and WRF with coupled microscale parametrization. |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38671/37155.pdf |
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| Wang, He; Yang, Jingsong; Mouche, Alexis; Shao, Weizeng; Zhu, Jianhua; Ren, Lin; Xie, Chunhua. |
| Gaofen-3 (GF-3) is the first Chinese civil C-band synthetic aperture radar (SAR) launched on 10 August 2016 by the China Academy of Space Technology (CAST), which operates in 12 imaging modes with a fine spatial resolution up to 1 m. As one of the primary users, the State Oceanic Administration (SOA) operationally processes GF-3 SAR Level-1 products into ocean surface wind vector and plans to officially release the near real-time SAR wind products in the near future. In this paper, the methodology of wind retrieval at C-band SAR is introduced and the first results of GF-3 SAR-derived winds are presented. In particular, the case of the coastal katabatic wind off the west coast of the U.S. captured by GF-3 is discussed. The preliminary accuracy assessment of... |
| Tipo: Text |
Palavras-chave: GF-3; Synthetic aperture radar (SAR); Ocean surface wind; Validation. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00396/50731/51435.pdf |
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| Li, Xiuzhong; Zhang, Biao; Mouche, Alexis; He, Yijun; Perrie, William. |
| This paper reports Ku-band normalized radar cross section (NRCS) at low incidence angles ranging from 0° to 18° and in the wind speed range from 6 to 70 m/s. The precipitation radar onboard the tropical rainfall measuring mission and Jason-1 and 2 have provided 152 hurricanes observations between 2008 and 2013 that were collocated with stepped-frequency microwave radiometer measurements. It is found that the NRCS decreases with increasing incidence angle. The decrease is more dramatic in the 40–70 m/s range of wind speeds than in the 6–20 m/s range, indicating that the NRCS is very sensitive to low incidence angles under extreme wind conditions and insensitive to the extreme wind speed. Consequently, the sea surface appears relatively “smooth” to Ku-band... |
| Tipo: Text |
Palavras-chave: NRCS; Extreme wind conditions; Low incidence angles. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00385/49659/50197.pdf |
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| Bringer, Alexandra; Chapron, Bertrand; Mouche, Alexis; Guerin, Charles-antoine. |
| Existing models for the short-wave spectrum of the sea surface are not consistent with microwave satellite data when multi-bands and multi-incidence data sets are considered. We devise a simple parametric model for the short-wave omnidirectional spectrum of the sea surface on the basis of a three-band (C, Ku, and Ka) and multi-incidence (low, moderate, and large) data set and an improved analytical scattering model, namely the non-Gaussian Weighted Curvature Approximation. This spectrum is also constrained by several optical measurements which provide a priori conditions on the total and filtered mean-square slopes. It is compared with classical models such as Elfouhaily and Kudryavtsev unified curvature spectra. Significant differences are observed at... |
| Tipo: Text |
Palavras-chave: Microwave ocean remote sensing; Omnidirectional spectrum. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00174/28562/28378.pdf |
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| Wang, He; Mouche, Alexis; Husson, Romain; Chapron, Bertrand. |
| Synthetic Aperture Radar (SAR) in wave mode is a powerful sensor for monitoring the swells propagating across ocean basins. Here, we investigate crossing swells in the Indian Ocean using 10-years Envisat SAR wave mode archive spanning from December 2003 to April 2012. Taking the benefit of the unique "fireworks" analysis on SAR observations, we reconstruct the origins and propagating routes that are associated with crossing swell pools in the Indian Ocean. Besides, three different crossing swell mechanisms are discriminated from space by the comparative analysis between results from "fireworks" and original SAR data: (1) in the mid-ocean basin of the Indian Ocean, two remote southern swells form the crossing swell; (2) wave-current interaction; and, (3)... |
| Tipo: Text |
Palavras-chave: Crossing swells; Synthetic aperture radar; Wave mode; Fireworks analysis; Indian Ocean. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00679/79110/81601.pdf |
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| Hauser, D.; Tison, C.; Amiot, T.; Delaye, L.; Mouche, Alexis; Guitton, Gilles; Aouf, L.; Castillan, P.. |
| CFOSAT (the China France Oceanography Satellite) is a joint mission from the Chinese and French Space Agencies, devoted to the observation ocean surface wind and waves so as to improve wind and wave forecast for marine meteorology, ocean dynamics modeling and prediction, climate variability knowledge, fundamental knowledge of surface processes. Currently under Phase D (manufacturing phase), the launch is now planned for mid-2018 the later. The CFOSAT will carry two payloads, both Ku-Band radar: the wave scatterometer (SWIM) and the wind scatterometer (SCAT). Both instruments are based on new concepts with respect to existing satellite-borne wind and wave sensors. Indeed, one of the originalities of CFOSAT is that it will provide simultaneously and in the... |
| Tipo: Text |
Palavras-chave: Satellite; Radar; Surface ocean waves; Surface ocean wind; Scatterometer; CFOSAT. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00363/47468/47487.pdf |
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| Jiang, Haoyu; Mouche, Alexis; Wang, He; Babanin, Alexander V.; Chapron, Bertrand; Chen, Ge. |
| Numerical wave models are powerful tools for investigating global wave climate. Here a global wave hindcast is employed to estimate the global pattern of crossing swells. However, the global patterns of crossing swells derived from the model are different from those derived from the synthetic aperture radar (SAR) wave mode products of quasi-linear inversion, indicating one of them is questionable. The comparison shows that the first two most energetic swells inversed by SAR are often not in accordance with the first two most energetic swells in the model, and this will have a large impact on the statistics of the data. Before this problem is solved, SAR wave products of quasi-linear inversion should be treated with care in wave climate studies. |
| Tipo: Text |
Palavras-chave: Synthetic aperture radar; Quasi-linear inversion; Crossing swells; Wave climate. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00369/47979/48003.pdf |
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| Registros recuperados: 58 | |
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