Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: 

RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 4
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
Analysis of Dual-Frequency Ocean Backscatter Measurements at Ku- and Ka-Bands Using Near-Nadir Incidence GPM Radar Data ArchiMer
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
Imagem não selecionada

Imprime registro no formato completo
New Observations From the SWIM Radar On-Board CFOSAT: Instrument Validation and Ocean Wave Measurement Assessment ArchiMer
Hauser, Daniele; Tourain, Cedric; Hermozo, Laura; Alraddawi, D.; Aouf, L.; Chapron, Bertrand; Dalphinet, A.; Delaye, L.; Dalila, M.; Dormy, E.; Gouillon, F.; Gressani, Victor; Grouazel, Antoine; Guitton, Gilles; Husson, R.; Mironov, Alexey; Mouche, Alexis; Ollivier, A.; Oruba, L.; Piras, E.; Suquet, R. Rodriguez; Schippers, P.; Tison, C.; Tran, Ngan.
This article describes the first results obtained from the Surface Waves Investigation and Monitoring (SWIM) instrument carried by the China France Oceanography Satellite (CFOSAT), which was launched on October 29, 2018. SWIM is a Ku-band radar with a near-nadir scanning beam geometry. It was designed to measure the spectral properties of surface ocean waves. First, the good behavior of the instrument is illustrated. It is then shown that the nadir products (significant wave height, normalized radar cross section, and wind speed) exhibit an accuracy similar to standard altimeter missions, thanks to a new retracking algorithm, which compensates a lower sampling rate compared to standard altimetry missions. The off-nadir beam observations are analyzed in...
Tipo: Text Palavras-chave: Spaceborne radar; Radar cross-sections; Surface waves; Sea surface; Instruments; Altimeter; Ocean wave spectra; Radar measurements; Scatterometer; Sea surface; Spaceborne radar; Speckle noise.
Ano: 2021 URL: https://archimer.ifremer.fr/doc/00677/78869/81168.pdf
Imagem não selecionada

Imprime registro no formato completo
Estimation of Wind Direction in Tropical Cyclones Using C-Band Dual-Polarization Synthetic Aperture Radar ArchiMer
Fan, Shengren; Zhang, Biao; Mouche, Alexis; Perrie, William; Zhang, Jun A.; Zhang, Guosheng.
Under extreme weather conditions, the imprints of kilometer-scale marine atmospheric boundary layer roll vortices on the ocean surface are clearly visible in synthetic aperture radar (SAR) images of storms. Therefore, information about wind direction in storms can be obtained by analyzing SAR image features caused by boundary layer rolls. VH-polarized SAR imagery captures the structural features of storms well and shows prominent image gradients along the radial directions of the storm. The signal-to-noise ratios of VH-polarized images are small in low wind speed areas, but they are large in the same regions of VV-polarized images. Also, the capability of retrieving the atmospheric rolls orientation in VV-polarization is found to be sensitive to incidence...
Tipo: Text Palavras-chave: Synthetic aperture radar; Radar polarimetry; Wind speed; Atmospheric modeling; Spaceborne radar; Radar measurements; Synthetic aperture radar (SAR); Tropical cyclone (TC); Wind direction.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00609/72143/70953.pdf
Imagem não selecionada

Imprime registro no formato completo
Comparison of the Sentinel-1B Synthetic Aperture Radar With Airborne Microwave Sensors in an Extra-Tropical Cyclone ArchiMer
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
Registros recuperados: 4
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional