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1.
UWAN-MAC: An Energy-Efficient MAC Protocol for Underwater Acoustic Wireless Sensor Networks 总被引：2，自引：0，他引：2
In this paper, we propose a distributed, scalable, energy-efficient media access control (MAC) protocol that works despite long, unknown propagation delays of the underwater acoustic medium. This protocol can be used for delay-tolerant applications such as underwater ecological sensor networks between energy-limited nodes. Our protocol differs significantly from ALOHA, multiple access with collision avoidance (MACA), and the media access protocol for wireless LANs (MACAW) in that energy is the main performance metric in our case rather than bandwidth utilization. We show that under a realistic underwater sensor network scenario, our MAC protocol wastes only 4% of the transmit energy and only 1.5% of the receive energy due to collisions, when the average number of neighbors is four, and the duty cycle is 0.004. This distributed, scalable MAC protocol has the potential to serve as a primer for the development of energy-efficient MAC protocols for future underwater sensor networks. 相似文献
2.
随着海洋强国战略的推进和实施,水下传感器网络广泛应用于海洋资源探测、污染监测、辅助导航和水下军事侦察等领域,具有十分重要的意义。由于水下传感器所携电池充电或更换困难,如何减小传输能耗、在传感器能量受限的情况下提升网络生存期是亟须解决的关键问题之一。据此,提出了一种动态蚁群路由算法,考虑了每次传输后的节点剩余能量,作为路径优化的条件之一,基于蚁群算法在每次传输中选择最优路径,并在每次传输完成后更新路由表,让更多的节点参与信息传输,以提高节点的利用率。仿真结果表明：动态蚁群路由算法同时兼顾了能耗平衡和最小传输能耗,大大提高了网络生存期。分析结果对水下传感器网络的路由协议设计有一定的参考意义。 相似文献
3.
Lifetime Prolonging Algorithms for Underwater Sensor Networks 总被引：3，自引：0，他引：3
1.IntroductionRecent advances in acoustic communication,sensor networks and ad hoc networks have motivatedthe development of UASNs which are generallyformed by a surface station,autonomous underwater ve-hicles(AUVs)and sensor nodes that possess sensing,si… 相似文献
4.
对表层海洋动力学及其调控机制的认识对准确认识海洋自然变化过程及其未来对气候变化的响应具有重要意义。志愿观测船作为自动观测系统的载体和样品采集平台的优势使其在提升人类对于表层海洋的观测能力方面具有极大优势。本文系统性地回顾了志愿观测船的概念、发展历史、现状和未来发展趋势。基于志愿观测船的诸多海洋观测项目的成功显示了，随着快速发展的传感器技术，志愿观测船能够以经济有效的方式显著地提升表层海洋现场观测的时间和空间分辨率。未来的海洋观测系统应该综合利用包括志愿观测船在内的多种海洋观测平台的优势。 相似文献
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随着对水下目标特性研究的深入和声学探测技术的发展,基于单模态的阵列式信息融合或基于空间信息的分布式信息融合的水下目标识别方法研究已有一定成果,但针对复杂海况导致单一物理场或单一融合层次的系统识别性能提高有限等方面影响的水下目标识别方法研究还有所不足,因此,开展基于多模态深度融合模型的水下目标识别方法研究可利用模态互补,共享信息而提升识别率。文中在国内外研究基础上,深入研究了基于到达时差法和多模态方法组合的检测方法,初步形成了基于水声环境空间中多模态深度融合模型的识别框架,开展了海洋中典型自然与人为事件的信号分析与特征提取,并在此基础上,设计新型基于海底基站的被动识别系统。该系统同步记录和由位置等组成的时间序列标记声、磁和压数据,可实现高精度、高分辨率的识别。本研究可满足未来海洋观测对高性能水下目标探测、定位和跟踪系统的迫切需要,为海洋安全监管、海洋突发事件应急响应等领域提供新的技术手段和科学参考。 相似文献
6.
The Water Framework and Habitats Directives require the evaluation of both the conservation and ecological status of macroalgae communities at water body or habitat level. However, assessments of macroalgal communities are highly time-consuming, both in terms of sampling effort and laboratory processing. These constraints have brought about their oversight in many marine monitoring programs, especially in subtidal environments. By using data from intertidal and subtidal macroalgae assemblages of Mouro Island (North coast of Spain) we wanted to identify possible cost-effective methods for monitoring this biological indicator, based on both high taxa levels and use of representative taxa. Multivariate analyses were applied using different data transformations. The results show that macroalgal communities are robust to aggregation to genus or even family level. Moreover, the outcomes show that transformation types introduce higher variation in the multivariate pattern of samples than the taxonomic level to which organisms are identified. Also, the study supports the use of representative taxa as a surrogate to overall community structure. Therefore, we conclude that a rapid-assessment by means of field evaluations, based on coverage of representative taxa, is a reliable alternative for the assessment of macroalgae status. In addition this procedure allows evaluation at a broader spatial scale (water body or habitat level) than traditional quantitative sampling procedure does. 相似文献
7.
高精度CTD剖面仪电导率传感器的研究和实验 总被引：3，自引：2，他引：3
高精度CTD剖面仪是海洋863项目的重要组成部分，是海洋调查和水文观测必不可少的仪器，本文详细论述了CTD剖面仪中电导率传感器的研制方法和过程，并给出传感器现已达到的水平，提出还需要进一步进行的工作和深入研究的问题。 相似文献
8.
传感器优化配置的修正逐步累积法 总被引：1，自引：0，他引：1
讨论了模态实验中传感器的配置问题。利用结构振型矩阵转置的 QR分解得到传感器的初始配置。以模态置信度 MAC矩阵的最大非对角元为目标函数 ,利用本文提出的修正逐步累积法得到传感器的配置 ,并提出传感器配置必须结合优化效果和经济性 2方面综合考虑 相似文献
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《Oceanic Engineering, IEEE Journal of》2009,34(2):170-180
10.
海洋环境监测与现代传感器技术 总被引：4，自引：0，他引：4
本文论述了海洋环境监测对传感器的需求,分析了现代传感器技术的特点和关键技术,概述了海洋环境监测化学和生物传感器的近期进展,最后对发展海洋环境监测现代传感器技术提出了建议。 相似文献
11.
A web-based distributed system for monitoring and forecasting of the marine environment has been developed in line with INfrastructure for SPatial InfoRmation in Europe (INSPIRE) and Global Monitoring for Environment and Security (GMES) recommendations for a European Spatial Data Infrastructure (SDI). This system, called DISPRO, enables integration and distribution of multi-source data from satellites, aircraft, and in situ instruments, as well as results from numerical models. Geographic data and metadata are stored on a set of distributed computer nodes and retrieved and integrated by a web GIS client by means of Open Geospatial Consortium (OGC) Web Map Server (WMS) technologies. A profile of ISO 19115 was developed for metadata handling, using eXtensible Markup Language (XML) as a platform independent encoding mechanism. DISPRO has been demonstrated in six European coastal zone and ocean regions in the spring and summer of 2005. The overall positive experiences of both service providers and end users indicate that the system should be further developed into an operational GMES service. 相似文献
12.
We develop methods for automatic environmental monitoring of disposal sites on the deep ocean floor using chemical sensor arrays and statistical hypothesis testing. Such sites have been proposed to relocate dredge materials from harbors and shipping channels. The transport of pollutants is modeled as a diffusion process, and the measurement and statistical models are derived by exploiting the spatial and temporal evolution of the associated concentration distribution. We derive two detectors, the generalized likelihood ratio (GLR) test and the mean detector and determine their performance in terms of the probabilities of false alarm and detection, The results are applied to the design of chemical sensor arrays satisfying criteria specified in terms of these probabilities, and to optimally select a number of sensors and time samples. Numerical examples are used to demonstrate the applicability of our results 相似文献
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14.
Desa E. Maurya P.K. Pereira A. Pascoal A.M. Prabhudesai R.G. Mascarenhas A. Madhan R. Matondkar S.G.P. Navelkar G. Prabhudesai S. Afzulpurkar S. 《Oceanic Engineering, IEEE Journal of》2007,32(2):353-364
This paper provides a study on the development and the use of a small autonomous surface vehicle (ASV) that automatically follows programmed mission transects, while measuring sensor outputs along the tracks. It discusses the mechanical construction of the ASV, the distributed architecture of controller area network (CAN)-based nodes for science and vehicle payloads, high-speed radio-frequency (RF) communications, the performance of the heading autopilot, global positioning system (GPS)-based guidance algorithm, and the mission programming technique. The field trials of the ASV, performed off the coast of Goa, India, are focused on retrieving the 2-D spatial distribution of surface chlorophyll, which is one of the useful parameters in characterizing the nature of calibration-validation (CALVAL) sites for ocean remote sensing needs. A further benefit of ASVs is that they can be built at a low cost and used in monitoring applications of diverse coastal ecosystems. 相似文献
15.
中高空间分辨率宽波段光学卫星已成为赤潮监测的主要数据源,但与水色卫星传感器不同,中高空间分辨率卫星传感器主要面向陆地应用,其波段数量少、宽度大,由此对赤潮探测带来的影响尚待研究。为此,本文基于不同优势种赤潮实测高光谱数据、时空同步的GF-1 WFV2、GF-1 WFV3传感器影像、Sentinel-2A MSI传感器影像及GF-6 WFV传感器影像,探究了波段设置、光谱响应函数、信噪比及空间分辨率对赤潮探测的影响,并分析了红边波段赤潮探测优势。结果表明:波段设置对赤潮探测影响大,特别是红光波段和红边波段的中心波长和波段宽度;波段设置相同的情况下,赤潮探测精度受光谱响应函数的影响大,受信噪比的影响较小;空间分辨率对赤潮探测的影响较大,空间分辨率的提升有助于提高赤潮探测的精度。红边波段赤潮探测实验表明,较之红光波段,基于红边波段的赤潮探测具有明显的优势,平均F1-Score提高了11%。本文的研究结果一方面可为赤潮中高空间分辨率卫星探测的数据选取提供理论依据,另一方面可为中高空间分辨率卫星传感器的设计提供参考。 相似文献
16.
Autonomous underwater vehicles (AUVs) have many scientific, military, and commercial applications because of their potential capabilities and significant cost-performance improvements over traditional means for performing search and survey. The development of a reliable sampling platform requires a thorough system design and many costly at-sea trials during which systems specifications can be validated. Modeling and simulation provides a cost-effective measure to carry out preliminary component, system (hardware and software), and mission testing and verification, thereby reducing the number of potential failures in at-sea trials. An accurate simulation can help engineers to find hidden errors in the AUV embedded software and gain insights into the AUV operations and dynamics. This paper reviews our research work on real-time physics-based modeling and simulation for our AUVs. The modeling component includes vehicle dynamics, environment and sensor characteristics. The simulation component consists of stand-alone versus hardware-in-the-loop (HIL) implementation, for both single as well as multiple vehicles. In particular, implementation issues with regard to multitasking system resources will be addressed. The main contribution of this paper is to present the rationale for our simulation architecture and the lessons learned. 相似文献
17.
海洋声层析是1979年美国科学家W.Munk等人提出的,通过测量传播时间等声传播信号有关参量反演声波所穿越的海洋特征,得到大面积海域中的海洋动力学状态及其变化的估计。声层析方法自提出以来受到各国的重视。在最初的20 a间,以全球测温计划(ATOC)为代表的一系列验证实验推动了声层析的理论研究、设备研制和应用。步入21世纪后,声层析与海洋动力学的数据同化、利用滑翔机等设备的移动声层析以及沿海声层析得到重视,并进行了相关的理论与实验研究。纳入成像旗下的声层析希尔伯特方法、有效低功耗的分布式传感网络声层析,以及被动声层析,或将成为声层析未来研究的重要方向。 相似文献
18.
This paper presents a multi-Bernoulli filter for tracking the direction of arrival(DOAs) of time-varying number of targets using sensor array. Our method operates directly on the measurements of sensor array and does not require any detection. Firstly, more information is reserved and compared with the after-detection measurements using a finite set of detected points. It can significantly improve the tracking performance, especially in low signal-to-noise ratio. Secondly, it inherits the advantages of the multi-Bernoulli approximation which models each of the targets individually. This allows more accurate multi-target state estimation, especially when targets cross. The proposed filter does not need clustering step and simulation results showcase the improved performance of the proposed filter. 相似文献
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Tine Missiaen 《Marine Geophysical Researches》2005,26(2-4):145-155
The design of very high resolution (VHR) 3D marine surveys not only depends on the theoretical considerations of seismic imaging,
but is also dictated by the field conditions and the available budget. The main geophysical controlling factors include the
depth and dip of the target, and horizontal and vertical resolution. Working in shallow water environments and at high frequencies
will imply constraints on sampling, array directivity and positioning accuracy. In this paper we describe the main requirements
and constraints involved in VHR 3D acquisition. The second part of the paper focuses on the flexible acquisition system “Opus3D”
recently developed for shallow water investigations. The system provides improvements in imaging resolution in a relatively
simple and cost-effective way. Acquisition and positioning constraints limit the system to nearshore studies. The experience
gained from various surveys with this new acquisition system allow us to formulate a number of practical specifications and
guidelines for 3D survey design in shallow water. 相似文献