海底地形数据组织与可视化选取技术

海洋测绘数据信息化是构建智慧海洋的基础, 而海底地形数据是海洋测绘数据中的重要内容。为更加便捷和高效地 管理与利用地形数据, 本文结合工程实际需求, 研发了海底地形数据管理平台。首先, 基于海底地形数据的特点, 提出多分 辨率海底地形组织模型, 对不规则区域的海底地形进行多分辨率模型构建, 实现了对多波束实测数据的组织管理; 在此基础 上, 提出了多尺度海底地形分级渲染优化算法与海底地形数据空间截取算法, 利用分级渲染与数据裁剪算法实现对海底地形 数据的可视化表达预览和选取服务; 最后, 以典型的多波束测深数据为例, 基于研发平台完成了数据从存储 、组织管理到可 视化预览选取的一体化管理与服务, 验证了本文算法的可靠性与实用性, 同时可为海底地形数据管理服务提供一定参考。     

基于多波束数据的海底地形建模技术

比较了基于多波束数据的几种建模技术,针对多波束数据量大的特点,提出了通过建立空间索引数据块并结合MQS插值方式来构建海底DEM模型。实验结果表明,该技术可实现多波束数据海底地形的建模与实时渲染。     

渤海海底地形特征

基于2004—2010年渤海海底地形地貌调查资料,结合前人对渤海海底地形的认识,对渤海海底地形5个区(辽东湾、渤海湾、莱州湾、渤海中央盆地和渤海海峡)的地形及微地形,进行了全面的分析描述。并与1985年出版的渤海地形图进行比较,寻找渤海地形近几十年来的变化并分析其原因。分析表明:渤海海底地形平缓,从辽东湾、渤海湾和莱州湾三个海湾向渤海中央盆地及东部渤海海峡倾斜,平均水深18m;由于环境变化和人类活动,导致部分近岸海域的水深比40多a前的水深变浅,而渤海中央盆地发生侵蚀,水深加深。     

基于GEBCO的海底热液区地形复杂度分析方法研究

海底热液区地形复杂度是热液活动场的重要指标数据,获取地形复杂度指标数据,为系统研究全球海底热液区分布特征具有重要意义。阐述了地形复杂度和GEBCO数据的基本应用情况,介绍了基于数字地形模型数据进行地形复杂度计算的基本方法,提出了海底热液区地形复杂度计算的窗口序列分析法和基本步骤,实例分析了伊豆—小笠原海底热液活动亚带的地形复杂度情况。     

南海海底地形的卫星测高数据反演

深入讨论了重力异常与海深的关系 ,在考虑地壳均衡补偿效应影响的基础上 ,推导了由重力异常用FFT技术计算海深的模型。最后 ,利用推导的模型联合测高卫星数据和海洋重力资料反演了中国南海 2 5′× 2 5′海底地形     

基于航渡式水深数据的海底地形DEM建模方法

针对航渡式水深测量资料海量、条带式分布的数据特点,提出了分块抽稀、区域建模、拼接整合的海底地形DEM建模思路,可有效提高不规则形状水深资料的建模效率,丰富海底地形DEM获取手段。实验证明,该方法具有结构简单、操作便利、内存占用少、计算效率高等特点,能够实现基于航渡式水深数据的海底地形DEM建模。     

卫星测高资料在反演海底地形中的应用

首先论述了利用卫星测高数据反演海底地形两类常用算法即解析算法和统计算法的基本原理和数学模型，在此基础上基于最小二乘配置理论，提出了统计算法的改进模型，使用新模型在南中国海地区进行了海底地形反演计算，并将反演结果与实际船测水深进行比对，进一步验证改进模型的可靠性和有效性。     

对海底地形可视化技术的探讨

本文给出了海底地形可视化技术的一般概念,并介绍了常用于实现海底地形可视化的技术和手段。     

冲绳海槽海底地形的补偿模式研究

本文从区域补偿和实验均衡出发,导出了上部负载和下部负栽相关时理论均衡响应函数的计算公式,计算了弹性板有效工不同以及上部负载和下部负载的比例不同时的理论均衡响应函数曲线,并对曲线形态进行了初步的讨论。     

基于CGAL和OpenGL的海底地形三维可视化

为了实现大量离散多波束水深测量数据快速网格化和地形三维可视化表达,提出了一种基于CGAL库的离散数据快速构建三角网,并利用OpenGL库实现了海底地形的三维可视化和自由漫游的方法,降低了编程实现的难度,海底地形细节显示清晰,并与Surfer软件的实现效果进行了对比.     

基于BP神经网络的海底地形复杂度自动分类方法研究

针对海底地形复杂程度分类问题,在考虑传统水深均值的基础上引入坡度和起伏度两个地形因子作为表征海底地形复杂程度的分类指标并进行量化,对水深数据空间分辨率进行统一,建立包含18种典型海底特征的海底地形复杂度分类库,利用BP神经网络对建立的分类库进行训练学习。为验证该方法的有效性和适用性,选取地形复杂度不同的4块实验区分别采用统计学方法和BP神经网络算法进行海底地形复杂度进行分类,对比发现该方法可以实现海区海底平坦、一般、复杂三种地形的自动识别与分类,并保留实验区海底地形复杂度细节信息。     

多波束测深海底数字地形模型的建立

针对多波束测深数据集,采用改进的距离反比权重算法和多细节层次模型技术来建立海底数字地形模型（DTM）。结果表明：本方法具有较高的精度和效率,可以满足不同分辨率要求的DTM应用。     

NetCDF物理海洋数据云存储技术研究

物理海洋数据具有多维、时空和海量等特征,主要以NetCDF结构化文件格式进行存储。然而,在分布式环境中,结构化文件存在数据块寻址困难、边界不易判定等问题,制约着大数据场景下的存储及应用。论文设计基于HDFS+Spark的NetCDF物理海洋数据云存储方案,首先采用HDFS分布式存储技术存储和管理物理海洋数据;并设计基于Spark并行计算框架的数据分片方案,复写读取接口获取分布式环境下的NetCDF文件数据块地址,实现了物理海洋数据的高效率存储与查询分析。选取中国海域100 a时长的物理海洋数据进行波高-周期散布图统计实验。结果表明:在数亿级记录数条件下,文中方法可将查询分析耗时由集中式文件存储方式的2 300 s缩短至50 s内,效率较集中式文件存储方式提升95%以上,验证了该方法的正确性和有效性。     

基于GDAL和NetCDF的影像金字塔构建方法

介绍了GDAL和NetCDF在图像数据处理和栅格数据调度上的帮助和优势,提出了一种新的影像金字塔模型构建方法,从底层开发的关键技术上做了改进优化,提高了影像重采样方法的运行效率,在此研究领域上提供了一定的理论和实践基础。     

用数学形态学变换提取地性线的一种方法

地性线是非常重要的地形结构信息,应用领域十分广阔。采用单纯的矢量方法提取的地性线往往不连续,比较零碎。阐述了利用数学形态学的流域分割算法提取地性线的原理,介绍了基于等高线,采用矢量栅格混合算法提取地性线的具体步骤,最后,给出了结论,实验结果表明,采用本文提出的算法是可行的,提取的地性线有较好的连续性。     

海底重力取样技术的探讨

对重力取样器的用途、使用及相关技术进行了较全面的介绍,尤其介绍取样作业中的一些实际经验,对该取样器的技术特点、相关技术和未来发展方向进行深入的探讨。     

Assessment of Impact on Seafloor Features in INDEX Area

Abstract

Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in pre-disturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions.     

Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model

In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis,a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper,resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom,while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force elements built on the theory of terramechanics acting on each discrete element.To evaluate and verify the correctness and effectiveness of this new modeling and analysis method,typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method.In full consideration of the particular structure design of the pilot miner,the special characteristics of the seafloor soil and the hydrodynamic force of near-seafloor current,the dynamic simulation analysis of the miner is performed and discussed,which can provide useful guidance and reference for the practical miner system in design and operation.This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches.     

Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model

In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis, a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper, resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom, while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force elements built on the theory of terramechanics acting on each discrete element. To evaluate and verify the correctness and effectiveness of this new modeling and analysis method, typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method. In full consideration of the particular structure design of the pilot miner, the special characteristics of the seafloor soil and the hydrodynamic force of near-seafloor current, the dynamic simulation analysis of the miner is performed and discussed, which can provide useful guidance and reference for the practical miner system in design and operation. This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches.     

Underwater Terrain Positioning Method Based on Least Squares Estimation for AUV

To achieve accurate positioning of autonomous underwater vehicles, an appropriate underwater terrain database storage format for underwater terrain-matching positioning is established using multi-beam data as underwater terrain-matching data. An underwater terrain interpolation error compensation method based on fractional Brownian motion is proposed for defects of normal terrain interpolation, and an underwater terrain-matching positioning method based on least squares estimation (LSE) is proposed for correlation analysis of topographic features. The Fisher method is introduced as a secondary criterion for pseudo localization appearing in a topographic features flat area, effectively reducing the impact of pseudo positioning points on matching accuracy and improving the positioning accuracy of terrain flat areas. Simulation experiments based on electronic chart and multi-beam sea trial data show that drift errors of an inertial navigation system can be corrected effectively using the proposed method. The positioning accuracy and practicality are high, satisfying the requirement of underwater accurate positioning.