共查询到20条相似文献，搜索用时 125 毫秒
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天津港适航水深下界面淤泥容重值确定与适航水深测量 总被引：2，自引：3，他引：2
介绍了天津港适航水深下界面淤泥容重值确定依据，提出了1.28t/m^3或1.30t/m^3浮泥界面的建议，并初步探讨适航水深测量方法。 相似文献
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为了提高舰船航行实时规避碍航区的效率,提出了一种瞬时水深模型的碍航区自动提取方法。采用潮汐模型实时预报航行区域的动态水位,利用静态水深和动态水位构建瞬时水深模型;依据舰船的安全等深线,自动追踪瞬时水深模型的浅水碍航区,顾及航行区域的人工碍航区等因素,采用多边形合并算法进而获取瞬时水深模型的碍航区。实验证明:本文所提方法切实可行,能够实时自动地获取瞬时水深模型的碍航区集。 相似文献
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杭州湾深水航道东试挖槽浮泥研究 总被引：4，自引：0，他引：4
本文在对杭州湾深水航道东试挖槽中浮泥进行观测和淤泥特性试验研究的基础上，分析了槽中浮泥产生和消失的规律，认识到浮泥的固结是东试挖槽中泥沙回淤的主要形式。这对研究拟开挖的杭州湾深水航道东段的泥沙回淤规律，确定适航水深和航道维护方案等都有着较重要的指导意义。 相似文献
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天津港适航浮泥扫海测量 总被引：1，自引：2，他引：1
为解决港池和航道浮泥层的适航水深利用，实施了四波束双频测深仪和机械扫海具相结合扫测，试验结果表明可有效进行适航浮泥层的全覆盖测量。同时介绍了专门研制的轮轴拖曳式浮泥着底扫海器的结构与使用方法。 相似文献
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航碍区的提取是舰船航线分析与自动生成的基础。文中提出了一种基于海图水深的碍航区自动提取方法。该方法通过水深三角网的约束构建,安全等深线的自动追踪和碍航区的分析,实现了碍航区自动生成和表达。实验证明,所提方法可以根据安全水深变化,自动提取适应于不同舰船的碍航区。 相似文献
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洪咸东 《数字海洋与水下攻防》2021,4(5):412-415
基于 LM AUV 远程投送水雷使用特性的分析,梳理了 AUV 远程投送水雷时,雷位误差主要包括平台定位误差、航行误差和水雷末弹道误差,并构建了相应的散布概率函数,建立雷位散布模型。最后, 通过 MATLAB 程序仿真研究流速、水深及自主航距等因素对 AUV 远程投送水雷雷位散布的影响。 相似文献
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海事测绘资料管理系统设计与实现 总被引：2，自引：1，他引：1
主要讨论了海事测绘资料管理系统中的三个主要模块：航海图书资料系统、专题测绘系统、电子文档系统的设计与实现，该系统通过对海图编绘过程中涉及到的纸质资料、电子文档资料及测绘基础数据进行系统管理，达到减少测绘工作量，提高海图编绘质量的目的。 相似文献
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Nigel R. L. Gooding 《Marine Geodesy》2013,36(3-4):197-203
Abstract The historical development of positioning in relation to the nautical chart is described. Present nautical charts are largely based on geodetic surveys which date from the nineteenth and early twentieth centuries. This gave rise to the use of many local datums and there has been a need to provide the mariner with information to enable him to transfer his position from one chart to an adjacent one on a different datum. The availability of the Global Positioning System (GPS) and the World Geodetic System 1984 (WGS84) datum enables positioning on a single worldwide datum to become a reality. The important factors affecting the adoption of WGS84 as the datum for nautical charts—namely, data availability and the practical and political considerations—are discussed. New developments in the use of nautical charts, the electronic chart display and information systems, and the delineation of international boundaries and territorial limits all give rise to the requirement for improved positional accuracies. Recent experience in the use of GPS both in the provision of control for shore stations of electronic position‐fixing systems and the provision of position for hydrographic surveys is briefly discussed. 相似文献
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This paper establishes techniques and methods to determine a variety of boundaries associated with 200 nautical miles beyond the continental shelf. The methods, based on topography, slope and second-deriv- ative profile integrated analysis, are now able to identify automatically the foot of the continental slope （FOS）. By analyzing the sedimentary profile, the points of 1% sediment thickness are recognized. Through the intersection, cut, deletion and mergence calculation of the extrapolated data set of fLxed-point series, the method succeeds in generating automatically the extrapolated boundaries, including the FOS＋60 M line, the 350 M line, and the 2500 m＋100 M line. In addition, based on the automatic analysis of the topographic profile, it can be applied to determine rapidly the points of maximum water depth. Taking the northern Okinawa Trough （OT） as an example, these methods are used to calculate and examine the boundaries in- cluded in the Submission by the People＇s Republic of China Concerning the Outer Limits of the Continental Shelf beyond 200 Nautical miles in Part of the East China Sea （ECS）; the boundaries thus derived have a solid scientific and rational basis. 相似文献
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To overcome smoothness inconsistencies in depth contours interpolated from sounding data, this paper proposes a smoothing method based on the fitting of multi-segment Bezier curves considering navigational safety. The basic principle of this method is the division of a generated depth contour into a series of bends categorized as either convex bends or concave bends. Different smoothing strategies are designed for different bends while considering the safety constraint. Convexity-preserving Bezier curves are used to fit convex bends. For concave bends, the line segment of the bend is utilized as a boundary to construct a control polygon within the interior of the bend, after which a Bezier curve is constructed based on the polygon. Experiments with real data are implemented, and the results are compared with those of other methods. The results show that the smoothing procedure for depth contours with angularities is effective and respects the safety constraint; moreover, the shape characteristics are preserved, and high positional accuracy is achieved. In addition, the proposed smoothing method is free of topological inconsistencies. 相似文献
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In current practice in the development of hydrographic information systems, the automatic acquisition of spatial data has been considered to be very difficult. One of the key problems is recognition and correct separation of a feature from a complex graphic background. For these problems, this article presents a new concept of graph subsets to describe graph structures and composition rules of symbols in nautical charts. Based on this concept, morphological methods and operations in graph theory are unified into a coherent mathematical framework specially designed for analysis and recognition of binary chart images. In particular, an experimental system composed of feature extraction, symbol recognition, geometric reasoning, and intelligent control is developed for automatic digitization of nautical charts. 相似文献
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