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| Lurton, Xavier; Augustin, Jean-marie. |
| The quality estimation associated with individual soundings measured and computed by swath bathymetry sonars is a paramount issue which is most often imperfectly addressed today by sonar manufacturers. In this paper, a unified definition is proposed for a quality factor usable for all swath bathymetry sonars; the depth-relative error is directly estimated from the signal characteristics used in the sounding computation. The basic algorithms are presented for both phase-difference (oblique incidence) and amplitude (normal incidence) detection, and can be readily implemented in any swath bathymetry system using these detection principles. This approach gives a direct access to the objective bathymetric performance of individual soundings, and hence avoids... |
| Tipo: Text |
Palavras-chave: Bathymetry; Interferometry; Multibeam echosounder (MBES); Sonar. |
| Ano: 2010 |
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| Enjolras, Vivien; Vincent, Patrick; Souyris, Jean-claude; Rodriguez, Ernesto; Phalippou, Laurent; Cazenave, Anny. |
| The main limitations of standard nadir-looking radar altimeters have been known for long. They include the lack of coverage (intertrack distance of typically 150 km for the T/P / Jason tandem), and the spatial resolution ( typically 2 km for T/P and Jason), expected to be a limiting factor for the determination of mesoscale phenomena in deep ocean. In this context, various solutions using off-nadir radar interferometry have been proposed by Rodriguez and al to give an answer to oceanographic mission objectives. This paper addresses the performances study of this new generation of instruments, and dedicated mission. A first approach is based on the Wide-Swath Ocean Altimeter (WSOA) intended to be implemented onboard Jason-2 in 2004 but now abandoned. Every... |
| Tipo: Text |
Palavras-chave: Altimetry; Interferometry; Error budget; System analysis; Ocean; Mesoscale. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00284/39507/38002.pdf |
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| Le Bouffant, Naig; Berger, Laurent; Lurton, Xavier. |
| Bathymetric multibeam echosounders (MBES) classically improve their bottom detection resolution by increasing the number of beams with narrower beamwidths. Many independent detections are thus obtained when extracting one sounding in each beam. However when the pulse footprint on the bottom gets narrower than the beamwidth, which often happens at high incidence angles, it is possible to extract several independent bottom detections within the same beam. These high-density soundings extraction methods present a still higher interest for MBES designed with rather “wide” beams (say 3° or more), so as to offer other benefits, such as compacity, low-cost, or low sidelobe levels as for fishery applications. This paper presents a simple way to derive multiple... |
| Tipo: Text |
Palavras-chave: Multibeam; Bathymetry; Interferometry; Beamwidth. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00146/25719/23801.pdf |
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| Kerr, Yann H.; Waldteufel, Philippe; Wigneron, Jean-pierre; Delwart, Steven; Cabot, Francois; Boutin, Jacqueline; Escorihuela, Maria-jose; Font, Jordi; Reul, Nicolas; Gruhier, Claire; Juglea, Silvia Enache; Drinkwater, Mark R.; Hahne, Achim; Martin-neira, Manuel; Mecklenburg, Susanne. |
| It is now well understood that data on soil moisture and sea surface salinity (SSS) are required to improve meteorological and climate predictions. These two quantities are not yet available globally or with adequate temporal or spatial sampling. It is recognized that a spaceborne L-band radiometer with a suitable antenna is the most promising way of fulfilling this gap. With these scientific objectives and technical solution at the heart of a proposed mission concept the European Space Agency (ESA) selected the Soil Moisture and Ocean Salinity (SMOS) mission as its second Earth Explorer Opportunity Mission. The development of the SMOS mission was led by ESA in collaboration with the Centre National d'Etudes Spatiales (CNES) in France and the Centro para... |
| Tipo: Text |
Palavras-chave: Interferometry; L-band; Sea surface salinity (SSS); Soil moisture; Soil Moisture and Ocean Salinity (SMOS); Vegetation water content. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00004/11483/8065.pdf |
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