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- 摘要
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- 实验方案
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[IEEE 2018 Fourth Underwater Communications and Networking Conference (UComms) - Lerici (2018.8.28-2018.8.30)] 2018 Fourth Underwater Communications and Networking Conference (UComms) - Communication Operations at THEMO: the Texas A&M - University of Haifa - Eastern Mediterranean Observatory
摘要： We introduce the communication operations of THEMO: the new Texas A&M - University of Haifa - Eastern Mediterranean Marine Observatory. THEMO includes moored sensors, surface sensors, and secondary moorings. In all cases, the data from the sensors is transferred in near real-time to a shore station where it is freely shared with the community. Variety of communication aids are used. These include underwater acoustic communications to connect the sensors onboard the secondary moorings with THEMO’s surface platform, underwater inductive communication to connect the moored submerged sensors to the buoy’s controller, and radio communication connecting the mooring to the shore station. After deployment of almost a year, our results show that the communication performance are reliable, and the data ?ows in all weather conditions. In this paper, we describe the mooring’s communication applications, and share the details of the different communication components.
关键词： Marine Observatories,THEMO,Submerged sensor,Communication from marine buoys,Underwater acoustic communication,inductive communications
更新于2025-09-09 09:28:46
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[IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - Robust Visual Odometry in Underwater Environment
摘要： The accurate estimation of pose and velocity of an autonomous underwater vehicle (AUV) is critical to ensure the repeatability and validity of scientific data that is captured using sensors onboard the AUV. A low-cost and effective way is by using stereo camera sensors to perform visual odometry (VO). However, this is a difficult problem in underwater due to poor imaging condition and inconsistent motion caused by water flow. This paper proposes a robust and effective stereo underwater VO system that can overcome aforementioned difficulties and accurately localize the AUV. Experimental results demonstrate that the proposed pipeline outperforms existing VO systems in underwater environment, as well as obtains a comparative performance on the KITTI benchmark dataset.
关键词： autonomous underwater vehicle,stereo camera,underwater,visual odometry,feature-based methods
更新于2025-09-04 15:30:14
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[ACM Press the Thirteenth ACM International Conference - Shenzhen, China (2018.12.03-2018.12.05)] Proceedings of the Thirteenth ACM International Conference on Underwater Networks & Systems - WUWNet '18 - Relay-assisted optical wireless communications in turbid water
摘要： Underwater optical wireless communication (UOWC) systems are subject to severe performance degradation due to undissolved particles that make the water turbid. The point source diffusion of a substance in water creates a Gaussian-distributed attenuation spread for a given time instance, which makes communication challenging. To overcome this issue, we propose a dual-hop UOWC system in which the transmitter-receiver link is assisted by several amplify-and-forward relay nodes. To characterize the performance gains of this relay system, we study the bit error rate assuming on-off keying modulation. We investigate the impact of key system and particle distribution parameters such as the transmit power, the number of relays, and the spatial position of the attenuation spread on the performance.
关键词： relays,Underwater optical wireless communications,amplify-and-forward,submerged particle distributions,bit error rate
更新于2025-09-04 15:30:14
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The Role of the Effect of Shadowing of Some Wavy Regions by Other Wavy Regions in the Formation of an Image of Snell’s Window
摘要： The shadowing of some regions of a wavy water surface by other regions can significantly influence the backscattered signal not only in the problem of remote monitoring of a water reservoir at grazing angles (e.g., in radar), but also in the problems of underwater vision. In this work, we present the results of a theoretical study of this phenomenon with respect to the model of underwater imaging of the sky (Snell’s window) near the image boundary. The numerical-simulation method is used to develop the statistically mean image of Snell’s window, which allows for the shadowing effects, and the corrected formula of the estimate of a wave parameter, namely, the water-surface slope variance, is obtained using the value of blurring of the boundary of Snell’s window.
关键词： underwater vision,wavy water surface,shadowing,numerical simulation,Snell’s window
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - Qingdao, China (2018.9.14-2018.9.16)] 2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - A Height Correction Algorithm Applied in Underwater Photometric Stereo Reconstruction
摘要： In water, light is attenuated significantly because of scattering and absorption, which causes the uneven distribution of illumination in background area. That results in gradient error and aggravates the accumulation of height error during the gradient integral in photometric stereo. It will cause the distortion of reconstructed surface. To relieve the distortion, this paper presents a height correction algorithm applied in underwater photometric stereo reconstruction based on height distribution in background area. A 2D quadratic function was used to fit the height error, and the error was removed from the reconstructed height. Then a more accurate reconstructed surface was obtained. The experimental results illustrate the effectiveness of the proposed method in water with different turbidity.
关键词： photometric stereo,height error fitting,underwater,height correction
更新于2025-09-04 15:30:14