Articles de revues : « Ocean optic »

1

Morais, Robert M. « Implementation of Fiber Optic Technology in Naval Combatants ». Marine Technology and SNAME News 24, n^o 01 (1 janvier 1987) : 59–71. http://dx.doi.org/10.5957/mt1.1987.24.1.59.

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This paper provides a summary of activities and developments that directly impacted the implementation of fiber optics on naval combatants. The paper concludes that the benefits are clear, that the technology has matured, and that implementation as a system element in ship design and construction is accelerating. The paper also includes a short tutorial on the basic elements of a fiber optic link as well as the advantages, disadvantages, and applications of fiber optics.

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Zugger, M. E., et R. E. Hoffman. « Fiber Optics for Shipboard Sensing and Information Transfer ». Marine Technology and SNAME News 27, n^o 06 (1 novembre 1990) : 361–77. http://dx.doi.org/10.5957/mt1.1990.27.6.361.

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Fiber optics has been a rapidly growing field over the past decade. It has been utilized extensively by the telecommunications industry, an application which requires the transmission of large amounts of information at a high data rate. More recently, many firms have initiated development of fiber optic sensors. These are transducers that use purely fiber optic technology for sensing physical parameters, such as pressure, temperature, and strain. Trends and projections for ships of the future indicate that dramatically increased monitoring and computer control will be necessary for most ship systems. Not only will automation be used for meeting reduced manning requirements, other economic constraints will require extensive machinery monitoring for improved maintenance scheduling. Integrated navigation systems on commercial ships will require high-resolution displays, and rapid data transfer between satellite, radar, and bottom-sounding sonar navigation subsystems. These applications will require fiber optics both in data transfer networks and in sensors. This paper is intended to apprise the marine engineering community of the potential benefits which fiber optic networks and sensors bring to shipboard installations. A brief tutorial on fiber optics is given, including a discussion of space, weight, and data rate advantages; the various fundamental sensing techniques are explained, and examples of prototype and commercially available sensors for potential shipboard use are provided. The report concludes with an example of a commercial ship application, and an assessment of the action needed by the ship design community and sensor vendors to reap the performance, safety, and economic benefits of this technology.

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GERDT, DAVID W. « Fiber Optic Coupler Sensors ». Naval Engineers Journal 102, n^o 3 (mai 1990) : 275–80. http://dx.doi.org/10.1111/j.1559-3584.1990.tb02651.x.

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Chave, Alan D., Gary Waterworth, Andrew R. Maffei et Gene Massion. « Cabled Ocean Observatory Systems ». Marine Technology Society Journal 38, n^o 2 (1 juin 2004) : 30–43. http://dx.doi.org/10.4031/002533204787522785.

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Future studies of episodic processes in the ocean and earth will require new tools to complement traditional, ship-based, expeditionary science. This will be enabled through the construction of innovative facilities called ocean observatories which provide unprecedented amounts of power and two-way bandwidth to access and control instrument networks in the oceans. The most capable ocean observatories are designed around a submarine fiber optic/power cable connecting one or more seafloor science nodes to the terrestrial power grid and communications backhaul. This paper defines the top level requirements that drive cabled observatory design and the system engineering environment within which a scientifically-capable infrastructure can be implemented. Commercial high reliability submarine telecommunication technologies which will be crucial in the design of long term cabled observatories are then reviewed. The top level architecture of a generic cabled observatory, describing the main subsystems comprising the whole and defining technological approaches to their engineering, is then described, along with some example design choices and tradeoff studies

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Kovač, Lea, Marija Volk, Maja Šuštar Habjan et Marko Hawlina. « Oxidative Stress in Antibiotic Toxic Optic Neuropathy Mimicking Acute LHON in a Patient with Exacerbation of Cystic Fibrosis ». Stresses 3, n^o 1 (14 mars 2023) : 387–96. http://dx.doi.org/10.3390/stresses3010028.

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The striking similarity of disc edema without leakage on fluorescein angiography, which is pathognomonic of Leber hereditary optic neuropathy (LHON), was present in a patient with cystic fibrosis with antibiotic toxic optic neuropathy. This similarity suggested the common effect of oxidative stress on retinal ganglion cells in inherited mitochondrial and antibiotic optic neuropathies. We present the case of a patient with advanced cystic fibrosis on chronic antibiotic treatment who experienced a rapid painless bilateral visual decline over a course of a few weeks. At examination, his corrected visual acuity was reduced to 0.3 in both eyes, with dyschromatopsia and central scotoma. The appearance of the fundus resembled the typical clinical features of acute LHON with hyperemic optic discs and tortuous vessels with no dye leakage from the optic discs on fluorescein angiography. Ganglion cell layer loss was seen on optic coherence tomography, with all findings pointing to LHON. Genetic testing did not reveal any LHON-specific mutations. After extended genetic testing, a heterozygous variant c.209C>T in the OPA3 gene on chromosome 19, g.46032648G>A, classified as a variant of unknown significance, was also found. After discontinuing antibiotics and general improvements in his health, surprisingly, his visual function completely improved. Later, he also received a bilateral lung transplant that further improved his general condition, and his vision remained normal. Excluding LHON, the transient optic neuropathy in our patient could be mainly due to antibiotic toxicity of linezolid and ciprofloxacin, which have been linked to mitochondrial dysfunction and advanced cystic fibrosis with hypoxic status. We suggest the possibility that patients with cystic fibrosis may be more prone to developing mitochondrial optic neuropathy, especially with additional risk factors such as chronic antibiotic therapy, which affect mitochondrial function, and can perhaps serve as a model for LHON.

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Ramesh, Raju, Dharmaraj Sathianarayanan, Vittal Doss Prakash, Arumugam Vadivelan, Sethuraman Ramesh, Gidugu Ananda Ramadass et Malayath Aravindakshan Atmanand. « Failure Analysis of Fiber Optic Communication System in Deep-Water Remotely Operated Vehicle ROSUB 6000 ». Marine Technology Society Journal 48, n^o 3 (1 mai 2014) : 63–72. http://dx.doi.org/10.4031/mtsj.48.3.11.

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AbstractSingle-mode fiber optic systems can play vital roles in cabled deep-water vehicle operations at greater depths (>3,000 m). One kind of single-mode fiber optic system, the ROSUB 6000, is used in a deep-water work-class remotely operated vehicle (ROV). Fiber optic link failure of ROV telemetry and sound navigation and ranging were noticed at a water depth of 3,050 m during the ROSUB 6000 system sea trials. A failure analysis of the fiber optic communication system was carried out with the link data logged during different phases of the deep-sea trials. The results from the failure analysis carried out during deep-sea trials showed an increase in the fiber optic link loss from a depth of 900 m onwards. Further analysis of the fiber optic link loss in the laboratory involved pressure and low-temperature testing of all the subsea components in the ROV telemetry link. From the laboratory pressure test results, it was concluded that pressure was not the root cause of the fiber optic link failure. On further analysis, a complete fiber optic link failure was noticed during the low-temperature testing of the subsea components. Furthermore, the low-temperature testing of the individual subsea components revealed that the fiber optic rotary joint (FORJ) insertion loss increased rapidly at low temperatures. This FORJ insertion loss led to complete failure of the fiber optic links in the ROV. The degradation of index-matching fluid in the FORJ was identified to be the root cause of fiber link failure.

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Kumari, C. R. Uma, Dhanalakshmi Samiappan, Kumar R. et Tata Sudhakar. « Fiber optic sensors in ocean observation : A comprehensive review ». Optik 179 (février 2019) : 351–60. http://dx.doi.org/10.1016/j.ijleo.2018.10.186.

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Suhandy, D., Kusumiyati et M. Yulia. « Discrimination between arabica and robusta coffees using NIR-integrating sphere spectroscopy coupled with hierarchical clustering analysis ». IOP Conference Series : Earth and Environmental Science 1038, n^o 1 (1 juin 2022) : 012034. http://dx.doi.org/10.1088/1755-1315/1038/1/012034.

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Abstract In Indonesia, coffee farmers preferred to produce arabica and robusta coffee. Regarding its superior quality and commercial values, now the demand for specialty arabica and fine robusta coffee is increasing. In this research, discrimination between the two coffees was evaluated using NIR-integrating sphere spectroscopy coupled with the hierarchical clustering analysis (HCA) method. NIR spectral data in the region of 1175-1650 nm was measured using a portable fiber optic NIR spectrometer equipped with an integrating sphere from Ocean Optics (NIR-Quest, Ocean Optics, USA). Arabica (n=10) and robusta (n=10) ground roasted coffee (with mesh 50) was prepared as samples. The principal component analysis (PCA) and hierarchical cluster analysis (HCA) were utilized in data analysis to discriminate between the specialty arabica and fine robusta coffee samples. The PCA and HCA results confirmed the good separation between the two coffees with arabica and robusta coffee samples were grouped in two distinct clusters. This result reveals that NIR-integrating sphere spectroscopy seems to be a potential analytical method dedicated to the discrimination of arabica and robusta coffee with minimum sample preparation.

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Mippo, Naiara Tieme, Paulo Henrique Kiohara Acyoli Bastos, Felipe Streitenberger Ivo et Olympio Lucchini Coutinho. « Photodetector optic power optimization to increase the gain on sub-octave microwave photonic link / Optimização da potência óptica do fotodetector para aumentar o ganho na ligação fotónica de microondas sub-octave ». Brazilian Applied Science Review 5, n^o 5 (16 septembre 2021) : 1990–2001. http://dx.doi.org/10.34115/basrv5n5-002.

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An investigation of the optic spectral components beating at the photodetector to recover the RF signal at the output of a sub-octave microwave photonic link is presented, by a theoretical and experimental approach. It is demonstrated the best efficiency is achieved when the carrier to sideband ratio (CSR) is 0 dB at a low bias voltage condition on Mach-Zehnder (MZM) intensity modulator. A RF power link gain improvement of 9.7 dB is demonstrated for a same photodetector incident optic power, compared with a link operating at quadrature bias voltage condition on the MZM.

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Mippo, Naiara Tieme, Paulo Henrique Kiohara Acyoli Bastos, Felipe Streitenberger Ivo et Olympio Lucchini Coutinho. « Photodetector optic power optimization to increase the gain on sub-octave microwave photonic link / Optimização da potência óptica do fotodetector para aumentar o ganho na ligação fotónica de microondas sub-octave ». Brazilian Applied Science Review 5, n^o 5 (16 septembre 2021) : 1990–2001. http://dx.doi.org/10.34115/basrv5n5-002.

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An investigation of the optic spectral components beating at the photodetector to recover the RF signal at the output of a sub-octave microwave photonic link is presented, by a theoretical and experimental approach. It is demonstrated the best efficiency is achieved when the carrier to sideband ratio (CSR) is 0 dB at a low bias voltage condition on Mach-Zehnder (MZM) intensity modulator. A RF power link gain improvement of 9.7 dB is demonstrated for a same photodetector incident optic power, compared with a link operating at quadrature bias voltage condition on the MZM.

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Logan, Catheryn. « Ushering In a New Generation of Optic and Photonic Sensors ». Marine Technology Society Journal 49, n^o 3 (1 mai 2015) : 34–42. http://dx.doi.org/10.4031/mtsj.49.3.13.

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Abstract As technology has advanced, so has our insatiable need to sense what is around us. This commentary discusses the markets that use optic and photonic sensors, which areas can expect growth, and which sensing technologies are mature and which are emerging. A brief discussion introduces some disruptive technologies that will enable smart sensing. Included is a more detailed understanding of the markets that are making use of fiber optic sensors and some gaps associated with that technology.

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Zhou Lingjun, 周灵钧, 于洋 Yu Yang et 孟洲 Meng Zhou. « 光纤海洋温盐深传感器研究进展 ». Laser & ; Optoelectronics Progress 58, n^o 13 (2021) : 1306019. http://dx.doi.org/10.3788/lop202158.1306019.

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Kubic, Thomas A., Mircea A. Comanescu et Tiffany J. Millett. « A Low-Cost Fiber Optic Visible Microspectrometer for the Small Forensic Science Laboratory ». Microscope 69, n^o 3 (2022) : 99–107. http://dx.doi.org/10.59082/dyyw7686.

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The logical first step in any traditional forensic visual examination of trace evidence samples is color comparison. However, comparing the color of two objects to determine if a common origin exists is largely subjective, unless the colors are far apart on the spectrum. To aid in the discrimination process, instrumental methods such as microspectrophotometry have been employed. A number of commercial units have been available over the years to make transmission, reflectance, and fluorescence measurements on these types of evidence, although many of these current and past units are quite costly. This paper describes the use of an Ocean Optics USB-2000+ fiber optic array detector (spectrometer) connected to existing laboratory microscopes and a laptop PC for such measurements. This spectrometer performed more than adequately for the determination of reflectance and transmission visible spectra of glass chips and dyed fibers.

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Goertz, Alex, et Andreas Wuestefeld. « Real-time passive monitoring with a fibre-optic ocean bottom array ». First Break 36, n^o 4 (1 avril 2018) : 55–61. http://dx.doi.org/10.3997/1365-2397.n0083.

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Albor, Nancy, John Herr, Steve Mastrogiovanni, Francis Mulderrig, Larry Nucci, Anthony Price, David Remner et James R. DiTaranto. « Comparison of Fiber Optic and Conventional Sensors for Naval Applications ». Naval Engineers Journal 108, n^o 2 (mars 1996) : 29–42. http://dx.doi.org/10.1111/j.1559-3584.1996.tb00502.x.

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Huang, Xiaodi, et Desheng Chen. « A novel architecture of fibre-optic interferometric hydrophone ». MATEC Web of Conferences 283 (2019) : 01001. http://dx.doi.org/10.1051/matecconf/201928301001.

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The fibre-optic interferometric hydrophone has been widely used in ocean acoustic applications. There are many different hydrophone systems in use. They can generally be classified as hull mounted, towed, or fixed (bottom mounted and vertical) array systems. Different optical architectures have evolved for each of the areas, which make a good case study on what aspects of a particular application influence the optical architecture. A novel architecture of fibre-optic hydrophone based on PMDI is theoretically and experimentally discussed in this paper. A novel optical configuration is proposed, and the modulation and demodulation system is built. A series of experiments are designed to analyse the characteristics of this system. The results of the experiments show that this type of fibre-optic interferometric hydrophone array has many advantages such as low noise, a large dynamic range.

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Tyler, S. W., D. M. Holland, V. Zagorodnov, A. A. Stern, C. Sladek, S. Kobs, S. White, F. Suárez et J. Bryenton. « Using distributed temperature sensors to monitor an Antarctic ice shelf and sub-ice-shelf cavity ». Journal of Glaciology 59, n^o 215 (2013) : 583–91. http://dx.doi.org/10.3189/2013jog12j207.

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AbstractMonitoring of ice-shelf and sub-ice-shelf ocean temperatures represents an important component in understanding ice-sheet stability. Continuous monitoring is challenging due to difficult surface access, difficulties in penetrating the ice shelf, and the need for long-term operation of non-recoverable sensors. We aim to develop rapid lightweight drilling and near-continuous fiber-optic temperature-monitoring methods to meet these challenges. During November 2011, two instrumented moorings were installed within and below the McMurdo Ice Shelf (a sub-region of the Ross Ice Shelf, Antarctica) at Windless Bight. We used a combination of ice coring for the upper portion of each shelf borehole and hot-point drilling for penetration into the ocean. The boreholes provided temporary access to the ice-shelf cavity, into which distributed temperature sensing (DTS) fiber-optic cables and conventional pressure/temperature transducers were installed. The DTS moorings provided near-continuous (in time and depth) observations of ice and ocean temperatures to a depth of almost 800 m beneath the ice-shelf surface. Data received document the presence of near-freezing water throughout the cavity from November through January, followed by an influx of warmer water reaching ∼150 m beneath the ice-shelf base during February and March. The observations demonstrate prospects for achieving much higher spatial sampling of temperature than more conventional oceanographic moorings.

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Chen, Jiandong, Tianying Chang, Qunjian Fu, Jinpeng Lang, Wenzhi Gao, Zhongmin Wang, Miao Yu, Yanbo Zhang et Hong-Liang Cui. « A Fiber-Optic Interferometric Tri-Component Geophone for Ocean Floor Seismic Monitoring ». Sensors 17, n^o 12 (28 décembre 2016) : 47. http://dx.doi.org/10.3390/s17010047.

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Southall, Brandon L., Christopher Clark, Kendra Daley, Sue Moore, John Payne, Roger Payne, Kate Stafford et al. « Acoustic monitoring of marine life with a fiber‐optic, ocean‐observing network. » Journal of the Acoustical Society of America 129, n^o 4 (avril 2011) : 2372. http://dx.doi.org/10.1121/1.3587683.

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Chamuel, JacquesR. « 4593385 Fiber optic sensor lead fiber noise cancellation ». Ocean Engineering 14, n^o 1 (janvier 1987) : i—ii. http://dx.doi.org/10.1016/0029-8018(87)90016-3.

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Griffiths, Richard W., et Herbert I. Chatterton. « Continuously Distributed Fiber Optic Monitoring System for Shipboard Applications ». Marine Technology and SNAME News 25, n^o 03 (1 juillet 1988) : 209–19. http://dx.doi.org/10.5957/mt1.1988.25.3.209.

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This paper suggests several areas of applicability wherein continuously monitored fiber optic cables of composite construction will improve the sensing ability of locating and reporting the conditions extant on ships of various types. By using continuous fiber cables strategically located throughout the ship that are compositely clad with different coatings to detect temperature, pressure and strain, an optically attenuated profile can be continuously monitored on a cyclical basis to report the specific conditions on a real-time basis. Preliminary bench test results of prototype jacketed fiber optic cable indicate that strains of 0.0004 to 0.003 in./in. can be detected as well as pressure changes of similar sensitivity. Currently, tests are being run to determine temperature sensitivity, and it is expected that comparable results will be achieved. With the development of the systems and improvement in jacketing materials, further refinements and expansion of capabilities are expected.

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Nykiel, Damian. « Comparison of methods of monitoring structure deformations based on tests of a column-plate slab ». Budownictwo i Architektura 20, n^o 4 (29 décembre 2021) : 005–16. http://dx.doi.org/10.35784/bud-arch.2705.

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This work includes a comparison of the methods of monitoring the deformations of a structure on the example of a flat plate slab test. Classic ESG (electrofusion strain gauges) and modern DFOS (distributed fiber optic sensors) were compared. During the research, both types of sensors were used on some of the reinforcing bars. The study aims to indicate the differences between the compared monitoring methods, both in terms of the obtained results and their utility values.

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Williams, Ethan F., María R. Fernández-Ruiz, Regina Magalhaes, Roel Vanthillo, Zhongwen Zhan, Miguel González-Herráez et Hugo F. Martins. « Scholte wave inversion and passive source imaging with ocean-bottom DAS ». Leading Edge 40, n^o 8 (août 2021) : 576–83. http://dx.doi.org/10.1190/tle40080576.1.

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Geotechnical characterization of marine sediments remains an outstanding challenge for offshore energy development, including foundation design and site selection of wind turbines and offshore platforms. We demonstrate that passive distributed acoustic sensing (DAS) surveys offer a new solution for shallow offshore geotechnical investigation where seafloor power or communications cables with fiber-optic links are available. We analyze Scholte waves recorded by DAS on a 42 km power cable in the Belgian offshore area of the southern North Sea. Ambient noise crosscorrelations converge acceptably with just over one hour of data, permitting multimodal Scholte wave dispersion measurement and shear-wave velocity inversion along the cable. We identify anomalous off-axis Scholte wave arrivals in noise crosscorrelations at high frequencies. Using a simple passive source imaging approach, we associate these arrivals with individual wind turbines, which suggests they are generated by structural vibrations. While many technological barriers must be overcome before ocean-bottom DAS can be applied to global seismic monitoring in the deep oceans, high-frequency passive surveys for high-resolution geotechnical characterization and monitoring in coastal regions are easily achievable today.

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DAVIDSON, STEVEN A., JOEL G. GRIMM, PHILIP M. BLUMENAU, KENNETH I. SCHULTZ, ALAN L. KACHELMYER, LEO J. SULLIVAN, WILLIAM E. KEICHER, MICHAEL HESS, ADAM PRINCE et MARY MARTIN. « An Airborne Passive/Active Electro-Optic Sensor System for Theater Ballistic Missile Defense ». Naval Engineers Journal 106, n^o 3 (mai 1994) : 192–207. http://dx.doi.org/10.1111/j.1559-3584.1994.tb02852.x.

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Zhang Dengpan, 张登攀, 冯. 盼. Feng Pan et 王永杰 Wang Yongjie. « Experimental research on continuous measurement of all fiber optic ocean temperature-depth profile ». Infrared and Laser Engineering 46, n^o 7 (2017) : 712002. http://dx.doi.org/10.3788/irla201746.0712002.

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Hathaway, Kent K., Richard D. Costley, Eric Smith, Troy Milburn et Jennifer R. Picucci. « Ocean wave seismic and acoustic noise detected with distributed fiber optic sensor array ». Journal of the Acoustical Society of America 134, n^o 5 (novembre 2013) : 4180. http://dx.doi.org/10.1121/1.4831323.

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Kolesnikova, Anastasia V. « International Project «ROTAKS» as a Factor in Improving the Global Infrastructure and the Legal Regime of Telecommunications ». Moscow Journal of International Law, n^o 3 (30 septembre 2014) : 192–97. http://dx.doi.org/10.24833/0869-0049-2014-3-192-197.

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International project ROTAKS with the participation of the Russian Federation incoming to the competition with other submarine cable networks of the foreign operators and representatives of the telecommunications market Eurasian transit - one of the most important factors in improving the global infrastructure and the legal regime of telecommunications projects. Implementation of the project ROTAKS is carried out by laying ﬁ ber-optic link at the bottom of the Arctic Ocean.

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Li, Gaochao, Yongjie Wang, Ancun Shi, Yuanhui Liu et Fang Li. « Review of Seawater Fiber Optic Salinity Sensors Based on the Refractive Index Detection Principle ». Sensors 23, n^o 4 (15 février 2023) : 2187. http://dx.doi.org/10.3390/s23042187.

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This paper presents a systematic review of the research available on salinity optic fiber sensors (OFSs) for seawater based on the refractive index (RI) measurement principle for the actual measurement demand of seawater salinity in marine environmental monitoring, the definition of seawater salinity and the correspondence between the seawater RI and salinity. To further investigate the progress of in situ measurements of absolute salinity by OFSs, the sensing mechanisms, research progress and measurement performance indices of various existing fiber optic salinity sensors are summarized. According to the Thermodynamic Equation of Seawater-2010 (TEOS-10), absolute salinity is recommended for sensor calibration and measurement. Comprehensive domestic and international research progress shows that fiber-optic RI sensors are ideal for real-time, in situ measurement of the absolute salinity of seawater and have excellent potential for application in long-term in situ measurements in the deep ocean. Finally, based on marine environmental monitoring applications, a development plan and the technical requirements of salinity OFSs are proposed to provide references for researchers engaged in related industries.

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Bowen, Andrew D., Dana R. Yoerger, Louis L. Whitcomb et Daniel J. Fornari. « Exploring the Deepest Depths : Preliminary Design of a Novel Light-Tethered Hybrid ROV for Global Science in Extreme Environments ». Marine Technology Society Journal 38, n^o 2 (1 juin 2004) : 92–101. http://dx.doi.org/10.4031/002533204787522776.

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This paper describes a new project to build an operational underwater vehicle that can perform scientific survey and sampling to the full depth of the ocean (11,000 meters). The vehicle, called a hybrid remotely operated vehicle (HROV), will operate in two different modes. For broad area survey, the vehicle will operate untethered as a autonomous underwater vehicle (AUV) capable of exploring and mapping the seafloor with sonars and cameras. After targets of interest have been found, the vehicle will be converted at-sea to become a remotely operated vehicle (ROV) that will enable close up imaging and sampling. The ROV configuration will incorporate a lightweight fiber optic tether to the surface for high bandwidth real-time video and data telemetry to the surface to enable high-quality teleoperation, additional cameras and lights, a manipulator arm, and sampling gear. This paper outlines the scientific motivation for the project as well as the feasibility of our design concept. Analysis of the fiber optic cable shows our approach to be practical even with fairly extreme current profiles. An overall approach to the vehicle design is also presented, including options for pressure housings and buoyancy materials.

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Lindsey, Nathaniel J., T. Craig Dawe et Jonathan B. Ajo-Franklin. « Illuminating seafloor faults and ocean dynamics with dark fiber distributed acoustic sensing ». Science 366, n^o 6469 (28 novembre 2019) : 1103–7. http://dx.doi.org/10.1126/science.aay5881.

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Distributed fiber-optic sensing technology coupled to existing subsea cables (dark fiber) allows observation of ocean and solid earth phenomena. We used an optical fiber from the cable supporting the Monterey Accelerated Research System during a 4-day maintenance period with a distributed acoustic sensing (DAS) instrument operating onshore, creating a ~10,000-component, 20-kilometer-long seismic array. Recordings of a minor earthquake wavefield identified multiple submarine fault zones. Ambient noise was dominated by shoaling ocean surface waves but also contained observations of in situ secondary microseism generation, post–low-tide bores, storm-induced sediment transport, infragravity waves, and breaking internal waves. DAS amplitudes in the microseism band tracked sea-state dynamics during a storm cycle in the northern Pacific. These observations highlight this method’s potential for marine geophysics.

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DeMetz, Fred C. « A single equation for predicting required ocean and seismic acoustic fiber optic sensor response ». Journal of the Acoustical Society of America 138, n^o 3 (septembre 2015) : 1948. http://dx.doi.org/10.1121/1.4934165.

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Thomas, Robert, Ronald J. Rapp, Marsha A. Spalding, Robert K. Stix, Maurice E. Kordahi et Neal S. Bergano. « Technology in Undersea Cable Systems : 50 Years of Progress ». Marine Technology Society Journal 49, n^o 6 (1 novembre 2015) : 88–109. http://dx.doi.org/10.4031/mtsj.49.6.4.

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AbstractUndersea cable systems provide a comprehensive example of how technology has changed during the 50-year publication history of the MTS Journal. From the 125-μm‐diameter glass optical fiber to the 12,000-ton cable ships, the design, manufacture, and installation of undersea communication systems rely on a remarkable intersection of technologies. The technologies supporting this industry have progressed significantly in many aspects. In 1965, coaxial analog systems were transmitting 128 three-kilohertz channels that were amplified by vacuum-tube-based amplifiers for consortiums of national telephone companies over simple point-to-point links. Today, a fiber-optic cable transmits 10 million times as much traffic, that is, tens of terabits of information per second, amplified by reliable erbium-doped fiber amplifiers, as part of mesh networks serving datacom, offshore oil and gas facilities, and scientific applications, each under a variety of ownership and operational models. Installation technology has changed along with the transmission technology, with advances in cable route surveys, ship positioning, cable burial, and use of remotely operated vehicles. System maintenance has become a much more practical endeavor since the advent of universal joint technologies and methodologies. Wet-mateable fiber-optic connectors enable remote, modular, subsea connection scenarios that serve a variety of applications. This paper reviews some of the history and evolution of the technology used in undersea cable systems and addresses future industry trends.

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Leun, E. V. « The basics of construction of jet-drop optical systems for measuring electric field strength. Parth 2 ». Omsk Scientific Bulletin, n^o 181 (2022) : 78–88. http://dx.doi.org/10.25206/1813-8225-2022-181-78-88.

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In this part of the article, the discussion of the construction of jet-drop optical measuring systems (JDOMS) for monitoring the electric field strength continues. The possibilities of increasing the resolution are considered. A variant of the interference JDOMS using triangulation stroboscopic measurements of displacements of charged moving droplets using a pulsed acousto-optic interferometer of transverse displacements of a laser beam is presented. The possibilities of increasing the charge/mass ratio of charged droplets, the features of using liquid metals and their two- and three-component alloys as liquids, the use of inhomogeneous droplets in the form of hollow, hollow microspheres similar to soap bubbles and/or based on a porous (dispersed) material are discussed.

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Davidson, Steven A., Joel G. Grimm, Philip Blumenau, Kenneth I. Shultz, Alan L. Kachelmyer, Leo J. Sullivan, William Kiechers et al. « Paper #14 : [192]. AN AIRBORNE PASSIVE/ACTIVE ELECTRO-OPTIC SENSOR SYSTEM FOR THEATER BALLISTIC MISSILE DEFENSE ». Naval Engineers Journal 106, n^o 4 (juillet 1994) : 129–33. http://dx.doi.org/10.1111/j.1559-3584.1994.tb03006.x.

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Leun, E. V., V. К. Sysoev, A. E. Shakhanov et Yu N. Mishin. « Features of modern circuitry of strain-resistive pressure sensors : fiber-optic pyrometric thermal compensation, optical radiation supply ». Omsk Scientific Bulletin, n^o 180 (2021) : 56–64. http://dx.doi.org/10.25206/1813-8225-2021-180-56-64.

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The article discusses the issues of improving strainresistive pressure sensors (PS) for their joint use with modern achievements of fiber optics (FO). The possibilities of implementation and features of FO pyrometric compensation of the temperature error of semiconductor and resistive strain-resistor, optical and/or electrical heating of the strain gage for selfcalibration of the pyrometer, power supply by optical radiation transmitted through a light guide with galvanic isolation of the PS circuit, increased noise reduction and fire and explosion safety are considered. Noise properties of semiconductor and resistive strainresistor are also considered.

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Singh, Vishaal, Christine McCarthy, Matthew Silvia, Michael V. Jakuba, Kathleen L. Craft, Alyssa R. Rhoden, Chris German et Theodore A. Koczynski. « Surviving in Ocean Worlds : Experimental Characterization of Fiber Optic Tethers across Europa-like Ice Faults and Unraveling the Sliding Behavior of Ice ». Planetary Science Journal 4, n^o 1 (1 janvier 2023) : 1. http://dx.doi.org/10.3847/psj/aca3ab.

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Abstract As an initial step toward in situ exploration of the interiors of Ocean Worlds to search for life using cryobot architectures, we test how various communication tethers behave under potential Europa-like stress conditions. By freezing two types of pretensioned insulated fiber optic cables inside ice blocks, we simulate tethers being refrozen in a probe’s wake as it traverses through an Ocean World’s ice shell. Using a cryogenic biaxial apparatus, we simulate shear motion on preexisting faults at various velocities and temperatures. These shear tests are used to evaluate the mechanical behavior of ice, characterize the behavior of communication tethers, and explore their limitations for deployment by a melt probe. We determine (a) the maximum shear stress tethers can sustain from an ice fault, prior to failure (viable/unviable regimes for deployment), and (b) optical tether performance for communications. We find that these tethers are fairly robust across a range of temperature and velocity conditions expected on Europa (T = 95–260 K, velocity = 5 × 10−7 m s−1 to 3 × 10−4 m s−1). However, damage to the outer jackets of the tethers and stretching of inner fibers at the coldest temperatures tested both indicate a need for further tether prototype development. Overall, these studies constrain the behavior of optical tethers for use at Ocean Worlds, improve the ability to probe thermomechanical properties of dynamic ice shells likely to be encountered by landed missions, and guide future technology development for accessing the interiors of (potentially habitable ± inhabited) Ocean Worlds.

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Guay, Christopher K., Gary P. Klinkhammer, Kelly Kenison Falkner, Ronald Benner, Paula G. Coble, Terry E. Whitledge, Brenda Black, F. Joseph Bussell et Tim A. Wagner. « High-resolution measurements of dissolved organic carbon in the Arctic Ocean byin situfiber-optic spectrometry ». Geophysical Research Letters 26, n^o 8 (15 avril 1999) : 1007–10. http://dx.doi.org/10.1029/1999gl900130.

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Ding, Guoping, Ning Jiang, Xiaoling Gao, Fu Wang et Xianfeng Wu. « Deformation monitoring of propeller underwater operation based on fiber optic grating sensing network ». Ocean Engineering 264 (novembre 2022) : 112308. http://dx.doi.org/10.1016/j.oceaneng.2022.112308.

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Wang, Hangzhou, Ying Chen, Hong Song et Samuel R. Laney. « A Fiber Optic Spectrometry System for Measuring Irradiance Distributions in Sea Ice Environments ». Journal of Atmospheric and Oceanic Technology 31, n^o 12 (1 décembre 2014) : 2844–57. http://dx.doi.org/10.1175/jtech-d-14-00108.1.

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Abstract A fiber optic–based spectrometry system was developed to enable automated, long-term measurements of spectral irradiance in sea ice environments. This system utilizes a single spectrometer module that measures the irradiance transmitted by multiple optical fibers, each coupled to the input fiber of the module via a mechanical rotary multiplexer. Small custom-printed optical diffusers, fixed to the input end of each fiber, allow these probes to be frozen into ice auger holes as small as 5 cm in diameter. Temperature-dependent biases in the spectrometer module and associated electronics were examined down to −40°C using an environmental chamber to identify any artifacts that might arise when operating these electronic and optical components below their vendor-defined lower temperature limits. The optical performance of the entire system was assessed by freezing multiple fiber probes in a 1.2-m-tall ice column, illuminating from above with a light source, and measuring spectral irradiance distributions at different depths within the ice column. Results indicated that the radiometric sensitivity of this fiber-based system is comparable to that of commercially available oceanographic spectroradiometers.

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Rabizadeh, Shayan, et Ali Esmaeili. « Hydro-optic interaction study on submerged unmanned underwater vehicles regarding to Snell's window ». Ocean Engineering 267 (janvier 2023) : 113224. http://dx.doi.org/10.1016/j.oceaneng.2022.113224.

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Liao, Yipeng, Jing Wang, Lei Yang, Shanshan Wang et Xu Chen. « In-Situ Detection for Ocean Internal Solitary Waves Based on a Miniaturized Microfiber-Optic Salinity Sensor ». IEEE Sensors Journal 20, n^o 24 (15 décembre 2020) : 14836–42. http://dx.doi.org/10.1109/jsen.2020.3009731.

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Yang, Zihui, Fanpeng Dong, Hongguang Liu, Xiaoxia Yang, Zhiwei Li et Bin Xue. « Direct Underwater Sound Velocity Measurement Based on the Acousto-Optic Self-Interference Effect between the Chirp Signal and the Optical Frequency Comb ». Journal of Marine Science and Engineering 11, n^o 1 (23 décembre 2022) : 18. http://dx.doi.org/10.3390/jmse11010018.

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Underwater sound speed plays a vital role in maritime safety. Based on the acousto-optic self-interference effect, we proposed a new method to measure underwater sound speed utilizing Raman–Nath diffraction, generated by the acousto-optic effect between an optical frequency comb and pulsed chirp signal. When the pulsed chirp travels between the measurement and reference arm in the experimental setup that we constructed, the same signal resulting from acousto-optic self-interference is produced. The time gap between the two identical signals represents the time interval. Thus, we can determine the time-of-flight using cross-correlation. The optical path difference between the two arms is double the flight distance of ultrasonic waves and can easily be obtained using femtosecond laser interferometry. The time gap and the distance can be used to measure sound speed. The experimental results show that the chirp signal improves the signal-to-noise ratio and expands the applicable time-of-flight algorithm. The waveform pulse width after cross-correlation is 1.5 μs, compared with 40 μs before. The time-of-flight uncertainty can achieve 1.03 ns compared to 8.6 ns before. Uncertainty of sound velocity can achieve 0.026 m/s.

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Aubrey, David G., Jennifer Wehof, Stephen O'Malley et Rajai Aghabi. « Elastomeric Risers in the Offshore Wind Industry ». Marine Technology Society Journal 54, n^o 6 (1 novembre 2020) : 77–83. http://dx.doi.org/10.4031/mtsj.54.6.2.

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AbstractFloating LiDAR systems (FLS) and other moored environmental monitoring systems are used extensively for wind and environmental assessments in offshore wind projects. In addition, wave energy converters (WECs) are being evaluated for more extensive use in coastal and deeper waters, most of which also require anchoring to the seabed. Since these systems must be moored, heavy anchors and typically heavy chain are used to secure the mooring and measurement/WEC buoy to the seabed. Disadvantages of present mooring technology include 1) damage to the seabed and benthic communities in vicinity of the mooring, as chain sweeps over the sea bottom; 2) an unnecessarily large watch circle at the water's surface; 3) slightly increased likelihood of marine mammal entanglement; 4) mooring damage from nearby fishing activity; and 5) likelihood of mooring failure due to self-entanglement within the mooring itself. This study presents an alternative mooring using mechanically compliant, elastomeric hoses to connect the buoyed system to the bottom anchor. Modeling the two mooring types with a typical buoy used in wind resource assessments shows a significant decrease in anchor drag area and surface watch circle with the use of the elastomeric hose versus the traditional chain and polyethylene line mooring. The hose also is equipped with copper conductors and/or fiber-optic conductors, providing power and data transmission between the bottom and the surface. For WEC solutions, the elastomeric hose provides similar benefits as for FLS and environmental monitoring systems, with the added advantage of being able to transmit power to the seafloor for distribution. For one WEC application, we have developed an elastomeric solution containing not only larger copper conductors to enable power transmission but also fiber-optic conductors to permit data transfer from a garage mounted on the bottom (servicing an autonomous underwater vehicle [AUV] or unmanned underwater vehicle [UUV], for instance) to the surface buoy for onward transmission to shore.

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Ramadass, Gidugu Ananda, Narayanaswamy Vedachalam, Arunachalam Umapathy, Raju Ramesh et Vandavasi Balanagajyothi. « Finite Element Analysis of the Influence of Ambient Temperature Variations on the Performance of Fiber Optic Gyroscope Sensing Coils ». Marine Technology Society Journal 51, n^o 1 (1 janvier 2017) : 16–22. http://dx.doi.org/10.4031/mtsj.51.1.2.

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AbstractTime transience-related nonreciprocal effect due to ambient temperature variations has significant influence in the bias stability performance of interference-type fiber optic gyroscopes (I-FOG). This paper presents the thermal finite element analysis (FEA) done on a 10-km-long I-FOG sensing coil wound with a diameter of 10 cm in a bipolar configuration for identifying its bias performance during ambient temperature variations. Results indicate that, with a sampling frequency of 0.5 kHz, the ambient temperature variation of 0.5°/min could degrade the bias stability performance of the I-FOG to tactical grade level, while maintaining ambient temperature variation within 0.01°/min is required to attain bias stabilities >0.001°/h, the performance required for the strategic grade applications. It is also identified that in a temperature stabilized environment, sensing coil with 10 and 40 layers requires a thermal stabilization time of about 9 and 26 min, respectively.

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Whitehead, A. M., W. P. Thomas et M. P. Wilkins. « Integrated Flying Aid and Mission Displays for Modern Combat Aircraft Incorporating a Digital Data Base ». Journal of Navigation 41, n^o 02 (mai 1988) : 261–75. http://dx.doi.org/10.1017/s0373463300009371.

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Electro-optic sensors – forward-looking infra-red and night vision goggles – are today providing a dramatic enhancement of low-level operational capability, but causing increased demands for precision navigation, situation awareness and advanced displays. Digital map displays, also available today, offer the flexibility of map presentation that is needed. In the future, terrain-referenced systems incorporating digital data bases hold the promise of the integrated flying aid and mission displays that are required for ‘all-weather’ operations. This paper describes first the fit and usage of the EO systems likely in a future combat aircraft and goes on to review the status of data-base systems. It establishes the baseline against which digital map systems and later terrain-referenced displays that exploit an elevation data base might be integrated into the aircraft.

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Ismangil, Agus, et Teguh Puja Negara. « KARAKTERISTIK LITHIUM TANTALAT (LITAO3) DIDOPING NIOBIUM BERVARIASI SUHU ». Komputasi : Jurnal Ilmiah Ilmu Komputer dan Matematika 15, n^o 2 (9 octobre 2019) : 182–86. http://dx.doi.org/10.33751/komputasi.v15i2.1384.

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Telah dilakukan pendopingan Litium tantalat LiTaO3 dengan cerium oksida pada substrat Si Tipe –P (100) dengan metode chemical solution deposition dan spin coating dengan kecepatan 3000 rpm selama 30 seconds. LiTaO3 memiliki konsentrasi 2.5M dan suhu annealing 800 °C. Film tipis LiTaO3 dikarakterisasi dengan ocean optic spectroscopy. Hasil dari karakterisasi spektroskopi film lithium tantalat yang didoping cerium oksida terlihat puncak absorbansi tertinggi pada suhu annealing 800oC menghasilkan panjang gelombang 934 nm, puncak absorbansi tertinggi pada film lithium tantalat pada suhu annealing 800 oC dengan kata lain film LiTaO3 banyak menyerap energi foton dari cahaya yang mengenainya serta film tipis litium tantalat menjadi cikal bakal sensor infra merah

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Roberts, B. « Waves in Magnetic Flux Tubes ». Symposium - International Astronomical Union 142 (1990) : 159–74. http://dx.doi.org/10.1017/s0074180900087891.

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The basic aspects of wave propagation in a magnetic flux tube are reviewed, with particular emphasis on the types of flux tube that occur in the solar atmosphere. Two fundamental speeds arise naturally in a description of wave propagation in a flux tube: the slow magnetoacoustic (cusp) speed cT, which is both subsonic and sub-Alfvénic, and a mean Alfvén speed ck. Both surface and body modes are supported by a tube. It is stressed that a flux tube may act as a wave guide, similar to the guidance of light by a fibre optic, or sound in an ocean layer, or seismic waves in the Earth's crust.

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Yoerger, Dana R., Annette F. Govindarajan, Jonathan C. Howland, Joel K. Llopiz, Peter H. Wiebe, Molly Curran, Justin Fujii et al. « A hybrid underwater robot for multidisciplinary investigation of the ocean twilight zone ». Science Robotics 6, n^o 55 (16 juin 2021) : eabe1901. http://dx.doi.org/10.1126/scirobotics.abe1901.

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Mesobot, an autonomous underwater vehicle, addresses specific unmet needs for observing and sampling a variety of phenomena in the ocean’s midwaters. The midwater hosts a vast biomass, has a role in regulating climate, and may soon be exploited commercially, yet our scientific understanding of it is incomplete. Mesobot has the ability to survey and track slow-moving animals and to correlate the animals’ movements with critical environmental measurements. Mesobot will complement existing oceanographic assets such as towed, remotely operated, and autonomous vehicles; shipboard acoustic sensors; and net tows. Its potential to perform behavioral studies unobtrusively over long periods with substantial autonomy provides a capability that is not presently available to midwater researchers. The 250-kilogram marine robot can be teleoperated through a lightweight fiber optic tether and can also operate untethered with full autonomy while minimizing environmental disturbance. We present recent results illustrating the vehicle’s ability to automatically track free-swimming hydromedusae (Solmissus sp.) and larvaceans (Bathochordaeus stygius) at depths of 200 meters in Monterey Bay, USA. In addition to these tracking missions, the vehicle can execute preprogrammed missions collecting image and sensor data while also carrying substantial auxiliary payloads such as cameras, sonars, and samplers.

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Voss, Kenneth J., et Giuseppe Zibordi. « Radiometric and Geometric Calibration of a Visible Spectral Electro-Optic “Fisheye” Camera Radiance Distribution System ». Journal of Atmospheric and Oceanic Technology 6, n^o 4 (août 1989) : 652–62. http://dx.doi.org/10.1175/1520-0426(1989)006<0652:ragcoa>2.0.co;2.

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Sigray, Peter, Peter Lundberg et Kristofer Döös. « Observations of Transport Variability in the Baltic Sea by Parasitic Use of a Fiber-Optic Cable ». Journal of Atmospheric and Oceanic Technology 21, n^o 7 (juillet 2004) : 1112–20. http://dx.doi.org/10.1175/1520-0426(2004)021<1112:ootvit>2.0.co;2.

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Articles de revues sur le sujet « Ocean optic »

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