双向转发检测技术在海洋环境观测数据传输网多链路冗余中的应用实践

在我国海洋环境观测数据传输网业务化运行体系当中,观测数据的实时不间断传输是保障数据传输网业务化运行的重要基础,而多链路冗余技术是保证观测数据实时不间断传输的重要技术手段。要实现多链路冗余,必须要通过双向转发检测技术结合策略路由配置等技术手段,达到主链路及备用链路无缝切换的目的。所以,需要研究双向转发检测技术和策略路由及浮动路由的配置技术,并通过上述两种技术手段的结合,最终实现多链路冗余,为海洋环境观测数据传输网业务化运行提供强有力的技术支撑。     

基于代理机制的“数字海洋”授权模型研究

"数字海洋"用户授权系统建设是整个信息基础框架构建的基础,是实现框架内数据与应用资源整合的前置条件。在对框架构建授权需求进行深入分析的基础上,结合目前网络授权方案的发展以及基于角色的用户访问控制技术,本文给出了用于实现框架授权的基于代理机制的授权模型,有效解决了节点用户授权的复杂需求。     

基于ArcIMS的南海地质与地球物理数据发布系统

结合计算机网络技术、WebGIS技术和数据库技术,对南海海洋地质与地球物理空间数据和属性数据的一体化存储、查询和分发进行了理论和方法上的研究,设计了南海地质与地球物理数据系统的整体结构、数据库结构以及系统的详细功能模块,并且运用ArcIMS技术实现了南海海洋地质与地球物理数据的共享和发布,使用户可以通过浏览器访问南海海洋地质与地球物理数据库,实现了建立南海海洋地质与地球物理信息共享服务体系、提高信息资源共享水平的目的.为用户发布和获取南海海洋数据提供了更为直观、快捷的平台.     

地理空间信息云平台负载调度算法设计

根据现代物联网对地理空间信息资源的大吞吐量需求,本文运用云计算技术、主从拓扑结构和多副本技术,设计了针对地理空间信息云平台的负载均衡调度算法,该算法通过统一的主服务器进行调度,并运用哈希函数使访问请求趋于均衡化。同时,我们将该算法运行在实际GIS系统中,模拟不同频度的用户访问请求,进行仿真。按照访问请求特征,将请求分为可预测高峰请求、随机高峰请求和系统响应请求三类,并分别统计请求的平均响应时间。结果显示,该算法有效可行,可在访问高峰期大幅减少用户平均响应时间。     

大数据量遥感影像的快速调度与显示

随着遥感技术的飞速发展,特别是传感器分辨率的提高,遥感影像的数据量急剧增加,如何有效地从这些庞大的影像数据中获取用户感兴趣的信息已成为当前的研究热点。针对大数据量影像的快速调度与显示问题,提出了一种基于文件的数据组织与管理方法,实现了单幅和多幅大数据量影像的实时调度与快速显示。经过与当前几种常用的商用软件进行对比发现:提出的方法占用计算机资源少,预处理后的影像浏览速度基本与数据量大小无关,可以在任意一台普通配置的计算机上无缝、平滑地快速显示大数据量影像。     

海洋监测设备动力环境实验室信息管理系统的构建

实验室信息管理系统(LIMS)为实验室提供了便捷、准确、及时、规范的技术服务,已经被越来越多的实验室认可与应用。针对海洋监测设备动力环境实验室的实验业务与信息管理,分别从业务流程、用户需求和功能需求进行了分析,并对系统功能进行了详细设计。系统由基础设施层、数据层、支撑功能层、业务系统、标准规范支撑体系与信息安全支撑体系六部分组成,分为对外和对内两个应用部分,根据不同用户的不同权限,对实验室信息、实验数据、设备数据以及新闻等信息分别有不同的权限。该系统能够满足实验人员、管理人员与一般用户的不同需求,实现了对海洋监测设备动力环境实验室信息、实验数据与实验资源的有效管理,提高了仪器设备预约效率,实现了测试仪器装置的最大程度共享,节省了人力、物力和财力,同时,便于仪器设备的维修与维护与用户快速获得实验室各类信息。     

海洋观测数据的卫星传输链路—以Iridium传输链路应用分析为例

为了使全球性的海洋观测数据能够及时、可靠、准确地接收,介绍了基于卫星网络海洋观测数据传输链路的组成,对卫星传输链路的3个组成部分进行详细说明,包括:Iridium,Argos,Inmarsat和中国北斗四种卫星网络系统及比较分析,各卫星网络对应发送终端的分类分析以及陆地接收系统数据下载方式的比较分析。以Iridium网络系统为例,建设可实现全球覆盖的海洋观测数据卫星传输链路,完成现场观测数据的实时回传,为海洋观测数据卫星传输链路的建设提供示范,对比PSTN和M2M两种数据下载方式,通过实验分析,结果表明该海洋观测数据的卫星传输链路具备可行性和可靠性,可以进行业务化运行。     

风云三号D气象卫星全球数据获取方法及数据分发

风云三号D气象卫星搭载10个载荷:中分辨率光谱成像仪Ⅱ、微波成像仪、微波温度计Ⅱ、微波湿度计Ⅱ、红外高光谱大气探测仪、近红外高光谱温室气体监测仪、广角极光成像仪、电离层光度计、空间环境监测器和全球导航卫星掩星探测仪。这10个载荷每天连续对地球探测,并获取数据,卫星将载荷探测数据经过实时空对地广播链路向全球用户广播;同时,通过延时空对地广播链路将全球延时数据对国内的广州、乌鲁木齐、佳木斯、喀什,北极及南极站进行数据下传,这四个国内站及两个极地站收到全球数据后,在45 min内,通过地面商用通信链路将数据传送到数据处理中心,数据处理中心对收到的数据进行汇集、分包、质量判断、预处理、产品生成等处理后,通过专线或互联网将数据发送给用户;同时,各气象、海洋及其他用户还可以通过用户利用站进行数据的接收及应用。     

USV-LIF遥测系统的控制系统设计与实现

无人船作为一种新型平台,在海洋环境监测中具有布放灵活、自动测量等优势。对于近岸港口等溢油事故发生频繁区域的环境监测,相比于传统的机载和船载溢油激光荧光遥感技术,采用无人船平台搭载激光荧光传感器进行探测更为方便有效。本文对基于无人船的激光荧光(USV-LIF)遥测系统进行总体方案设计,并详细设计了其控制系统,该系统包括岸基远程控制模块和USV-LIF现场机控制模块两部分。利用无线网络通信链路实现从岸基终端对USV-LIF现场机的远程控制与通信,并通过现场机的控制模块实现对USV-LIF现场机的仪器状态控制、数据采集以及时序控制等功能。在实验室条件下,对USV-LIF遥测系统的整体运行、远程控制数据传输以及系统长时间连续工作进行了模拟联调测试,结果表明,所研发的控制系统的功能基本达到了现场探测需求。     

基于残余自干扰获取的带内全双工水声通信系统结构方案与仿真

强自干扰抵消是带内全双工(In-Band Full-Duplex,IBFD)水声通信系统工程实现中的最大挑战。 近端接收端需结合模拟域及数字域进行联合干扰抵消才可将干扰强度降低至可接受水平。提出一种基于残余干扰获取的带内全双工水声通信系统结构设计方案,其特征为具备主、辅双采集链路,通过辅助采集链路实现对干扰信号的获取,并利用辅助采集链路与消干扰信号在数字域上的抵消结果作为主采集链路数字域上的线性滤波器的输入参考信号,以实现对残余干扰的抵消。该系统结构方案与现有系统结构方案相比,在有效克服功率放大器非线性影响的同时,可降低模拟域及数字域干扰抵消系统结构复杂度;仿真数据处理结果表明,该方案可实现公里级带内全双工水声通信。     

Improving the recreational value of Ireland's coastal resources: A contingent behavioural application

This paper measures willingness to pay (WTP) for public access to additional beach area and trail improvements to a coastal recreational site in the west of Ireland. The Contingent Behaviour model is used to measure the increased number of trips associated with improved public access using a connecting trail between two beach areas along a stretch of Irish coastline. Results show that improving access through the use of the connecting trail increases consumer surplus by €111.15 per person per annum. It is argued that in designing new regulation such as Marine Protected Areas (MPAs) for the management of Ireland's coastline, an understanding of the values the Irish public place on coastal recreational access will be important to manage the resource in a sustainable manner.     

Public willingness to pay for alternative management regimes of remote marine protected areas in the North Sea

Despite increasing attention paid to the value of marine resources, in particular marine protected areas (MPAs), their economic valuation focuses mainly on use values of ecosystem services such as fishery and tourism. Furthermore, most MPA related studies are carried out for coastal ecosystems, especially tropical coral reefs. The valuation of remote marine ecosystems is rare. The main objective of this paper is to estimate public willingness to pay (WTP) for alternative management regimes of a network of offshore MPAs in the North Sea under the Marine Strategy Framework Directive (MSFD). In a baseline valuation study carried out just before the adoption of the MSFD, beach visitors and a random sample of coastal and non-coastal residents were asked for their preferences for two alternative management options of three remote, ecologically sensitive areas with multiple use conflicts. Despite the lack of public awareness and familiarity with the offshore marine areas, a majority of 70% is willing to pay extra tax for their protection. Using a conservative value elicitation procedure, Dutch households are willing to pay on average maximum 0.25% of their annual disposable income to ban access and economic use. This serves as an indicator of what a network of remote MPAs in the MSFD is allowed to cost according to the Dutch tax payer.     

Valuing visitors' economic benefits of public beach access points

An increase in the population of coastal counties and popularity of coastal beaches as tourism destinations create difficulties for management agencies responsible for providing public beach access. The objective of this paper is to determine non-resident visitors to South Carolina beaches economic value for public beach access. Visitors are willing to pay an extra $6.60 per day for additional beach access points and parking or an aggregate of $93 million. Visitors' economic value of public beach access allows decision-makers the ability to better compare management policies in their efforts to provide sufficient public beach access through a target effective strategy.     

Local permit ownership in Alaska salmon fisheries

Changes in ownership of limited entry permits by “local” residents of the region where a fishery occurs may have significant economic and social implications for fishery-dependent regions. This paper examines changes in local permit ownership in Alaska salmon fisheries, for which a long-term decline in rural local permit ownership is an important policy concern. Theoretically, permit markets allocate permits over time to the individuals who are willing to pay the most for them. Any factors that differentially affect what local and non-local residents are willing to pay for permits may affect the equilibrium share of permits held by local residents. For remote rural fisheries in particular, these may include differences between local and non-local residents with respect to access to and costs of financing permits and boats, costs of travel to the fishery, opportunity costs of participation in the fishery, and many other factors. As a fishery increases in profitability, differences between local and non-local residents in access to financing matter more while differences in costs of travel and opportunity costs matter less in the relative ranking of what local and non-local residents are willing to pay for permits. This tends to increase the share of non-local residents among buyers willing to pay the market price for permits, reducing the equilibrium share of permits held by local residents. This leads to a conflict between two important policy goals: increasing fishery profitability and maintaining rural local permit ownership. Consistent with predictions of this theory, the local share of permit ownership in Alaska salmon fisheries is negatively related to permit prices (an indicator of fishery profitability).     

User fees as sustainable financing mechanisms for marine protected areas: An application to the Bonaire National Marine Park

Marine protected areas (MPAs) have proliferated globally in the past three decades. However, inadequate funding often prevents these management regimes from fulfilling their missions. Managers have become increasingly aware that successful protection of marine ecosystems is dependent not only upon an understanding of their biological and physical processes, but also their associated social and economic aspects. Unfortunately, economic values associated with MPAs and the natural resources they protect are rarely considered in decision-making and policy development. This study addresses this information gap by examining scuba divers’ willingness to pay for access to quality recreational sites in the Bonaire National Marine Park, Bonaire, Netherlands Antilles. The findings indicate that the US$10 annual diver user fee in effect at the time of the study could be increased substantially without a significant adverse effect on island tourism. Depending on question format, mean willingness to pay for annual access ranged from US$61 to US$134 (2002$). All model specifications support the conclusion that doubling the US$10 user fee would have virtually no impact on visitation rates. The increased revenue generated from this sustainable financing mechanism is more than sufficient to fund both current and enhanced marine park operations.     

WTO fisheries subsidies negotiations: implications for fisheries access arrangements and sustainable management

The paper considers the WTO negotiations on fisheries subsidies and the implications that envisaged disciplines will have on coastal developing countries. This is considered in relation to fisheries access agreements in the Central and Western Pacific where several least developed but resource rich island states such as Kiribati and Tuvalu are highly exposed to the risks associated with new WTO fisheries subsidies disciplines that do not consider their particular vulnerabilities. The paper considers some of the issues that coastal developing countries should incorporate into their emerging negotiating positions at the WTO. State-to-Sate fisheries access agreements which are often highly subsidised but where fishing vessel owners pay the equivalent of lump sum tax are paradoxically, the least distortionary and damaging to the environment. Strategies for managing the possible new disciplines are considered.     

The autonomous <Emphasis Type="Italic">Simpatico</Emphasis> system for real-time continuous water-quality and current velocity monitoring: examples of application in three Portuguese estuaries

This technical paper describes an autonomous recording system with remote data access for the continuous, long-term in situ monitoring of water quality and discharge, as well as current velocity. The Simpatico system has been recently deployed in three estuaries in Portugal (Mondego and Tagus in July 2007; Guadiana in March 2008), highly suitable to illustrate its multifaceted potential applications: surveillance of the effects of mitigation measures to combat eutrophication (lower Mondego Estuary); real-time implementation of boundary conditions for a water modelling system (upper Tagus Estuary); study of dam-induced impacts in terms of water quality, water discharge and sediment budgets (mouth of the Guadiana Estuary). An extract of recorded data serves as an example to discuss data reliability, as well as field maintenance of the system, with implications for labour and operational costs. The use of a new generation of copper-based anti-biofouling kits significantly reduced the need for field maintenance operations. Other examples of possible application of the system include the assessment of gas accumulation in coastal waters.     

Coastal initiative of the Global Terrestrial Observing System

The three global observing systems (the Global Climate Observing System (GCOS); the Global Oceanographic Observing System (GOOS); and the Global Terrestrial Observing System (GTOS)) are designed to detect and assess global change. A land-based coastal observing system initiative under GTOS is at the beginnings and will lead toward the integration of terrestrial and freshwater observations with marine observations under the auspices of coastal GOOS. The GTOS infrastructure already builds on national, regional and global programs for terrestrial observations, but more emphasis is needed on the unique circumstances of coastal ecosystems. Coastal GTOS will use the observing system philosophy and infrastructure to identify and improve access to data and information about coastal change; assist users to make that access systematically; ensure that appropriate measures are being or can be made; and integrate terrestrial observations with marine observations. Key variables have been defined for GTOS. But major challenges include evaluating these and others for coastal ecosystems and identifying the indicators of coastal condition that operate at appropriate scales.     

Analysis of the economic benefits associated with the recovery of threatened marine mammal species in the Canadian St. Lawrence Estuary

This paper examines Canadians' willingness to pay to recover the populations of three marine mammal species found in the St Lawrence Estuary. The valuation approach utilized a stated preference tool that is somewhat a hybrid between contingent valuation and a choice experiment with multiple species recovery program options and choices framed as referenda. Program options involved the use of a marine protected area and restrictions on whale watching and shipping industries. The estimated willingness to pay (WTP) for different levels of marine mammal recovery ranged from $77 to $229 per year per household and varied according to the species affected and the recovery program effort. A series of tests revealed that people would be willing to pay more for programs that contribute to greater increases in marine mammal populations, but the additional value of programs that improve a species status beyond the “at risk” threshold is relatively small.     

Classifying levels of protection in Marine Protected Areas

Marine Protected Areas (MPAs) are an important tool for the conservation of marine species and ecosystems. Yet despite the significant differences between marine and terrestrial systems in terms of their critical ecological processes, stresses, and relationships with cultural systems, methods used to characterize levels of protection for biological diversity in MPAs are all derived from schemes developed for terrestrial systems. A new system designed to classify levels of protection in MPAs is proposed, based on criteria specifically relevant to marine systems. MPAs are characterized by each of the seven criteria: designated use, quality of natural character, extent of protection throughout the year, extent of zoning into sub-areas for multiple uses, public access, extraction of resources, and size with respect to supporting critical ecological processes. Five levels of protection are defined, labeled I-V: Wilderness Management Area (Level I), Research Management Area, Ecological Management Area, Human Recreation Management Area, and Sustainable Resource Management Area (V). A level is assigned to an MPA based on the level that matches the largest number of categories across all seven criteria. The uses and benefits of this system of classification relative to existing systems are discussed and examples of its application are illustrated using data on 83 MPAs in California (USA) and 10 globally.