众包水深测量的关键技术研究与分析

基于对众包测深技术的试验分析,探讨提高众包测深数据精度的技术与方法的可行性,以期理清众包测深数据处理流程。其中涉及时间同步、数据自动处理、潮位改正、声速改正等多个技术与方法,并结合实际众包测深试验数据进行了验证与分析。结果表明,本文所述方法提高了船用测深仪数据精度,即采用船载测深仪获得的水深数据结果可满足IHO-S 44标准1等要求,基本满足了航道水深监测的要求。其结果有利于及时掌握航道水深变化,保障航行安全;同时为增强全球海洋测深覆盖范围、更新航海海图、提高水深监测能力提供帮助。     

风浪对众包测深数据的精度影响分析

针对当前众包测深数据精度难以掌控导致其难以应用的现状,通过构建船舶横摇姿态计算模型,分析了风浪这一重要海洋环境因素对众包测深数据精度的影响程度,得出了众包测深数据的推荐风浪条件和最低要求风浪条件。实验结果表明:①风浪等级增大,各测深点水深测量偏差随之加大,符合《海道测量规范》测深限差要求的测深点数量也随之减少,且在海底倾斜越严重的海域,表现更加明显;②3级风2级浪条件下的众包测深数据可满足限差要求;4级风3级浪时众包测深数据在不同海底倾斜程度下,满足限差要求的数据量不一样;5级以上风4级以上浪在海底倾斜程度超过7.5°时多数测深点不能满足限差要求。     

基于IHO“众源测深”理念的国家众源测深体系研究

针对中国沿岸水域存在大量水深测量空白区和我国全球海道测绘服务能力不足的问题,在对IHO"众源测深"理念进行分析研究的基础上,提出了建设国家众源测深体系的基本思路。通过设计国家众源测深体系结构模型,从政策和技术两个层面归纳体系建设的关键内容,并给出首选示范建设水域建议,提出了一条有效的建设路径。     

第18届国际海道测量大会对国产多波束测深系统研制的启示

国际海道测量组织大会海洋测绘仪器展是最重要的设备展会之一,世界上主要测绘设备生产商都展出了其最新的产品。通过该展览,了解国际多波束测深系统的进展和发展方向,对我国多波束测深系统的研制与生产都具有重要意义。     

多波束测深系统海底目标探测能力评估方法

为了有效衡量多波束测深系统的目标探测性能,提高舰船水下目标搜寻、援潜救生和打捞能力等,对当前多波束测深系统目标探测问题进行分析,推导了多波束测深系统目标探测分辨率估计模型。以SONIC 2024型多波束测深系统为例,分析了不同水深下在多波束测深系统垂直航迹方向、沿航迹方向分辨率的变化规律及量级大小,对覆盖宽带和航速等参数指标设置提出了合理建议,为多波束测深系统目标探测能力的准确评估提供依据,具有一定参考价值。     

海道测量规范与IHO标准的比较研究

为保障船舶航行安全,国际海道测量组织制定了国际海道测量标准并保持不断更新,我国也根据自身情况制定了海道测量的国家强制标准。从测深、定位、障碍物、潮位、潮流和底质等6个方面对国际海道测量标准和我国海道测量规范进行了分析比较,指出了它们在要求上的不同和差异,旨在供测量人员在实际工作中参考使用并推动国内测量规范与国际测量标准的衔接。     

海道测量水位改正通用模式研究

为满足海道测量作业发展实际需求,进行了海道测量水位改正通用模式研究.在单波束测深逐点逐时分区改正基础上提出了适于单、多波束测深的海量数据虚拟单验潮站改正模式,基于时差法、最小二乘拟合法数学模型以及海洋潮汐数值预报模型,研制了适于沿岸、近海水深测量的水位改正软件.     

EM120型多波束测深系统及在深海测量中的应用

与传统的单波束回声测深仪相比,多波束测深系统具有水深全覆盖无遗漏扫测,测量范围大、速度快,测深精度和分辨率高,记录数字化和实时自动绘图等优点。介绍了EM120型多波束测深系统深水系统的技术性能,分析了EM120在中沙深海区的测量试验情况及在深海区水深测量中的应用价值,提出了存在问题及其对策。     

主检测深线系统误差的探测与实现

针对海道测量中测深成果系统误差的评价问题,介绍了一种利用主、检测深线测深数据探测系统误差的方法,以实现测深中系统误差的科学评估。     

海道测量潮汐计算与应用

研究了应用于海道测量的潮汐数值预报方法,研制了海道测量潮汐计算与应用软件系统,介绍了该系统的组成与主要功能以及有关数学模型的建立与计算方法。应用本文的方法,可解决船载水深测量和机载激光测深的水位改正问题。     

海上导航信息远程传输监控技术研究与应用

将北斗通信技术、船舶自动识别系统技术、航标遥测遥控技术以及GPS差分技术进行有效结合,研制了海上导航信息远程传输监控系统,对我国中、远海海域装有AIS设备的船舶进行跟踪与监控、可疑船舶的辨认、船舶的岸基调度、航标遥测遥控、GPS差分信息远程播发等。相比单一技术的应用,海上导航信息远程传输监控系统不受天气条件限制,无需人员定期出海维护,具有设备集成度高、导航差错率低、功能全面、成本效益好等特点。     

IMO框架下智能船舶适航的法律规制研究

随人工智能技术发展,智能船舶因其无人化、智能化的特点而与传统国际法律制度产生碰撞。当前,国际海事组织将制定“海上自主水面船舶规则”工作提上日程,航行安全问题作为其中的高度优先事项,受到各国广泛关注。船舶适航作为承运人的主要义务之一,是保障航行安全的先决条件。但智能船舶是否需要符合适航标准,如果适用会产生哪些法律障碍并如何解决等诸多问题亟待研究。对此,应修订《国际海上避碰规则》并明确智能船舶适船技术标准,明确岸基操作人员的法律地位并制定其资格取得、培训、值班标准,明确安全配员标准及需船员在船承担的职责的履行方式。     

Automatic collision avoidance of multiple ships based on deep Q-learning

As the number of ships for marine transportation increases with the globalisation of the world economy, waterways are becoming more congested than before. This situation will raise the risk of collision of the ships; hence, an automatic collision avoidance system needs to be developed. In this paper, a novel approach based on deep reinforcement learning (DRL) is proposed for automatic collision avoidance of multiple ships particularly in restricted waters. A training method and algorithms for collision avoidance of ships, incorporating ship manoeuvrability, human experience and navigation rules, are presented in detail. The proposed approach is investigated not only by numerical simulations but also by model experiments using three self-propelled ships. Through the systematic numerical and experimental validation, it is demonstrated the developed approach based on the DRL has great possibility for realising automatic collision avoidance of ships in highly complicated navigational situations.     

Compliance with international emission regulations: Reducing the air pollution from merchant vessels

In September 1997, the International Maritime Organization (IMO) adopted an international convention protocol to reduce air pollution from ships, in order to achieve sustainable maritime development. This protocol has been approved by 15 member countries and will be enforced in May 2005. Pollutants emitted from ships, such as nitrogen oxides, volatile organic compounds, sulfur oxides, etc. will be regulated by this convention through ship inspections and issuance of certificates. Ships belonging to maritime countries such as Taiwan, which sail around the world and berth in commercial ports, must obey this convention. This study has investigated possible strategies, which may be adopted by maritime countries to conform to this IMO convention in order to reduce the air pollution from ships. A sea-going ship must prepare EIAPP and IAPP certificates for inspection by port-state-control officials, when the ship is anchored at a maritime port. These port-state-control officials may also require the continuous detection and sampling of a ship's emissions, while it is berthed at the port. Legislative support is necessary for successful implementation of these safeguards. It is suggested, therefore, that the administration of both navigational and environmental protection, in maritime countries, cooperate in the revision of relevant federal laws, to implement the provisions of the MARPOL 73/78/97 convention; in this way, the air pollution from ships can be effectively controlled. Installation of advanced detection equipment can effectively detect any ships’ violations of air pollution regulations. The Harbor Affairs’ Bureau should also establish a database of air pollution inspections for ships berthed within their harbor, requiring that ships’ equipment comply with the requirements of the MARPOL convention, for the reduction of air pollution.     

航海通告自动获取系统的设计与实现

目前,从互联网获取航海通告数据是提高海图产品现势性、保障舰船航行安全的主要途径之一。基于对国内外网站特点、网页结构及网络爬虫技术、数据库技术的研究,提出了自动获取航海通告网页数据的总体方案;通过研发应用系统,实现了通告爬取、数据整理、数据库管理等主要功能。测试结果表明:较之传统工作方式,利用该系统获取的航海通告数据具有准确性、完整性、实时性和高效性,将为海图一体化生产体系提供更高质量的基础数据源支持。     

基于AIS的船舶会遇局面紧迫度量化分析

近年来船舶大型化、高速化的发展以及数量的不断递增,导致船舶碰撞概率大大增加。为更好地保障船舶航行安全,提出船舶会遇局面紧迫度这一概念。该概念表征船舶在当前航行状态下由于一定范围内所有其他船舶的存在而处于的会遇局面的紧迫程度,其旨在帮助船舶驾驶员实时感知并掌握船舶在海上航行时所处会遇局面的状况,从而据此加以判断并及时采取措施规避碰撞风险。建立了船舶会遇局面紧迫度的计算模型,该模型以考虑到本船速度的动态圆形领域为空间约束条件,综合考虑其他船舶相对于本船的方位分布和距离这两个指标的影响,基于信息量量化紧迫度。利用2016年1月1日天津港AIS数据进行紧迫度的计算与分析,计算结果与实际相符,该计算模型能够准确反映船舶在航行过程中所处会遇局面的紧迫程度。利用双线性内插法建立天津港区域紧迫度二维彩色平面分布图,其表达效果优于传统热度图。     

对中国沿海RBN-DGPS系统升级意见的商榷

依据GPS现代化的新近发展,论述了用包括4个民用测距码的三个GPS导航定位信号,船舰只需用一台GPS信号接收机就可以实现精度为±3．66m的在航三维定位测量;同时阐述了用中国的CNSS系统、俄罗斯的GLONAASS系统和欧盟的Galileo系统的三个民用导航定位信号作定位测量,能够用其无电离层效应影响的站星距离,解算出精度为±1m左右的三维位置;而不必要花巨资去升级“中国沿海RBN—DGPS系统”。     

广利河口航道整治研究

广利河口拦门沙航道水深较浅,用双导堤结合航道疏浚进行整治。通过潮流定床模型试验对航道走向、导堤间距、高程、水流流态和堤头布置等进行了方案优化,同时采用局部动床定性试验进行了验证。推荐方案沿程流速、流态分布合理,基本能维持航道水深并满足设计船型的航行条件,可供类似河口治理参考。     

Model experiments on moored ships

At present the position keeping of ocean going vessels, offshore service vessels, etc., is performed by mooring systems to resist external forces under severe environments consisting of wave, current and wind. A variety of mooring systems are employed depending on the shape, principal dimensions, etc., of the vessels in addition to the surrounding conditions of the water areas. Ocean going ships are moored to the shore structures through a multiple system of moorings. The determination of the forces in the cables is essential for the design of moorings and the berthing structures. However, the ships engaged for offshore operations are moored by the mooring cables, spread around the ships with the other ends of the moorings anchored to the sea bed. In these cases, the required number and length of cables can be arrived for a given ship of known dimensions and environmental conditions. With the increased overall dimensions of the vessels, it is necessary to conduct a study on enhancing the accuracy in estimating the mooring system performance. Hence, the present work is mainly intended to carry out model tests to investigate the behaviour of moored ships that are subjected to wave and current loadings. These model experiments were conducted in a 30 m × 2 m × 1 m wave-current flume at the Ocean Engineering Centre, Indian Institute of Technology, Madras.