SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

New Observations From the SWIM Radar On-Board CFOSAT: Instrument Validation and Ocean Wave Measurement Assessment

Voss, K. J.; Morel, A.; Antoine, D..

The radiance viewed from the ocean depends on the illumination and viewing geometry along with the water properties, and this variation is called the bidirectional effect. This bidirectional effect depends on the inherent optical properties of the water, including the volume scattering function, and is important when comparing data from different satellite sensors. The current model of f/Q, which contains the bidirectional effect, by Morel et al. (2002) depends on modeled, not measured, water parameters, thus must be carefully validated. In this paper we combined upwelling radiance distribution data from several cruises, in varied water types and with a wide range of solar zenith angles. We compared modeled and measured L(view)/L(nadir) and found that the...

Tipo: Text

Palavras-chave: Radiance distribution; Optical properties; Camera system; Reflectance; Instruments.

Ano: 2007

URL: https://archimer.ifremer.fr/doc/00209/32011/30548.pdf

The EGIM, a generic instrumental module to equip EMSO observatories

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

Lanteri, Nadine; Legrand, Julien; Moreau, Bertrand; Lagadec, Jean-romain; Rolin, Jean-francois.

The EGIM aims to set up a number of ocean locations where the same set of core variables, including temperature, conductivity, pressure, dissolved O2, turbidity, ocean currents, and passive acoustics, are measured homogeneously: using identical hardware, the same sensor references, the same qualification methods, the same calibration methods, the same data format and access, and the same maintenance procedures. The EGIM provides all the services required to ensure the best measurement quality and long-term reliability in line with the Best Practices Handbook by FIXO3 and ESONET-EMSO Label, these services being sensor power distribution, time stamping, data storage and backup, protection against the environment and against fouling and bi-directional...

Tipo: Text

Palavras-chave: Europe; Instruments; Calibration; Metrology; Sea measurements; Oceans; Observatories.

Ano: 2017

URL: https://archimer.ifremer.fr/doc/00427/53881/54949.pdf

Hypson 400, a real time panoramic sonar.

A simple volumeter for small invertebrates

Monsaingeon, L.

The search for a panoramic, real-time, high frequency sonar has been a major goal for operating ranges where optical systems have established limitations. HYPSON 400 meets such requirements and provides a simultaneous and continuous beam-forming, no-scanning, wide opening system, using a hybrid beam-forming technique allowed by new component technologies. Up to seven images per second can be formed at a range of 100 meters, and more at shorter distances, as allowed by the speed of sound, thus providing the highest possible rate of information renewal required by operations at sea.

Tipo: Text

Palavras-chave: Instruments; Sonar imagery; Marine technology.

Ano: 1990

URL: http://archimer.ifremer.fr/doc/1990/acte-1156.pdf

Persoone, G..

The displacement technique for measuring the volume of plankton catches is well established, and a number of papers have been published describing suitable apparatus for this purpose including those by Frolander (1957), and Yentsch & Hebard (1957). Gnanamuthu (1952) reviews several papers dealing with equipment for measuring the volume of small aquatic animals and discusses his own volumeter. The apparatus here described employs a water column and is, therefore, more convenient to handle than previous designs which used a mercury column. It is inexpensive and simple to construct, and will measure to 0.01 or even 0.005 ccm. We have found it most useful in quickly measuring the volume of polychaetes or oligochaetes, small bivalves, small crustaceans, etc.

Three simple culture devices for aquatic invertebrates and fish larvae with continuous recirculation of the medium

Palavras-chave: Instruments; Marine invertebrates.

Ano: 1971

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3430

Sorgeloos, P.; Persoone, G..

The 3 culturing devices described are based on the principle of the classic air-water lift, which facilitates continuous recirculation and aeration of the cultivation medium. The first device is a "circulation cylinder", convenient for hatching eggs of the brine shrimp Artemia salina and for culturing algae and protozoans. In the second device, an internal basket (i.e., a glass cylinder with plankton-gauze bottom) prevents the animals being carried along in the air-water lift. The third device, analogous to the second, is provided with a lateral waste-drain and a water collector with siphon, which empties regularly into the main culture vessel. The second and third devices proved to be excellent for the cultivation of a variety of...

The flow-through column: a simple and multipurpose rearing device

Palavras-chave: Aquaculture; Fish larvae; Instruments; Marine invertebrates.

Ano: 1972

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3461

Mertens, J.; Persoone, G..

A simple flow-through system for culturing or colonization purpose is described. It consists of piled up petri-dishes placed on top of a water reservoir with an air-water lifting tube. Each of the seperately removable units is composed of the bottom of a petri-dish glued on top of the lid of another one. A short piece of plastic tubing, fitting tightly into an exentrically drilled hole in the bottom part of the unit, permits a continuous flow of water through the whole column.

An improved separator box for Artemia nauplii and other phototactic invertebrates

Palavras-chave: Aquaculture techniques; Experimental rearing; Instruments.

Ano: 1972

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3454

Persoone, G.; Sorgeloos, P..

1. A simple cylindrical hatching and separator box is described for Artemia salinanauplii (and other phototactic invertebrates), in which the "corner seeking effect" responsible for poor separation is avoided, and from which nauplii can be recovered very conveniently. 2. Separation is achieved by partly unscrewing an internal and closed cylinder from its fixed counter-part glued to the bottom of the box, till two slits are freed through which the nauplii migrate from the darkened internal hatching cylinder into the illuminated exterior compartment. Rescrewing the former cylinder separates the larvae from debris and unhatched eggs.