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911.
寇连坡 《青岛远洋船员学院学报》2007,28(4):11-13,17
本文主要阐述消除陀螺罗经指向误差的必要性,利用GPS卫星导航仪信息,自动消除陀螺罗经指向误差的原理与方法,自动消除陀螺罗经指向误差的优点等。 相似文献
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北斗卫星导航系统已成为服务于中国及其周边地区的区域系统,并成为在轨运行的三大卫星导航系统之一。兼容互操作是卫星导航系统的发展趋势,为方便导航用户选星的使用要求,分析三大卫星导航系统的服务性能,给出卫星导航系统服务性能指标及定义。结合国内外学者对卫星导航系统服务性能的研究,对GPS、GLONASS和COMPASS等三大卫星导航系统的空间信号精度进行分析。结果表明我国北斗卫星导航系统在服务范围内能够向用户提供与GPS系统相同精度的定位、授时服务,且服务精度优于GLONASS系统。 相似文献
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Caitlin M. Jensen Ellen Hines Barbara A. Holzman Thomas J. Moore Jaime Jahncke Jessica V. Redfern 《Coastal management》2015,43(6):575-588
Shipping traffic poses a worldwide threat to many large whale species. Spatially explicit risk assessments are increasingly being used as a tool to minimize ship-strike risk. These assessments often use static representations of shipping patterns. We used Automatic Identification System data to quantify variability in cargo shipping traffic entering and exiting San Francisco Bay, which contains some of the busiest ports in the United States, at three temporal resolutions: (1) before and after implementation of the California Air Resources Board's Ocean-Going Vessels Fuel Rule, (2) among seasons, and (3) day versus night. We used the nonparametric Mood's Median test to compare median daily distance traveled because the data were not normally distributed and the variance was not homogeneous. Our analyses show that shipping traffic off San Francisco is dynamic at both interannual and daily temporal resolutions, but that traffic was fairly consistent among the seasons considered. Our analyses emphasize the importance of economic and regulatory drivers on interannual shipping traffic patterns. Shipping traffic is expected to continue to change off the U.S. West Coast and to increase globally. These changes in shipping traffic could have implications for the risk of ships striking whales and should be included in risk assessments. 相似文献
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Over the past decade, the shellfish and finfish aquaculture industry has expanded rapidly in coastal British Columbia (BC) Canada. Foreshore and nearshore shellfish and finfish aquaculture leaseholds are sited in close proximity or in direct competition with habitat for wild shellfish. As a result, some wild shellfish harvesters believe shellfish farms are significantly reducing access to beaches and estuarine areas for wild harvesting, or that salmon farms are contaminating wild shellfish stocks. In this article, Geographic Information Systems (GIS) are used to analyze spatial and temporal trends in the growth of shellfish and finfish aquaculture tenures in BC, while interviews with stakeholders in coastal communities are used to explore user conflicts and the implications of changing access rights on the distribution of marine resources. Qualitative and quantitative findings suggest that shellfish aquaculture provides significant economic opportunities for coastal communities, but that such development may hold increased risk of spatial conflicts over marine habitat as the aquaculture industry continues to grow. 相似文献
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介绍了将GIS技术、计算机技术和基础信息的行业规范结合起来开发港口设施地理信息系统,以及该系统的建设目标、系统功能、系统结构与系统配置. 相似文献
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结合公路规划、设计、建设实际,针对现行公路路线CAD系统尚不足以解决公路可行性研究、路线方案选定这类多目标空间决策问题的现状,论述了引入地理信息系统的有关理论、方法和技术分析手段,建立基于GIS的公路路线方案决策支持系统的若干问题和系统开发构想。 相似文献
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就崖门5000t级出海航道疏浚工程在测量、船舶定位、实时监控等工作中GPS定位技术的广泛应用进行探讨。 相似文献
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