基于Global Mapper的航迹线的制作

在海上进行资源调查时,船舶航迹线的制作是必不可少的,船舶航行的轨迹和调查的工作量都能通过航迹线清晰而直观地反映出来。列举了航迹数据采集的几种方式,给出了数据提取的方法,再通过Global Mapper进行航迹线的绘制,该软件绘制的航迹线可根据需要更改颜色、粗细等参数,并可显示航迹线所在海域的水深变化情况,基于Global Mapper绘制的航迹线对成果资料的验收提供了更为可靠和有效的参考。     

水深测量计划测线布设与航迹控制算法

在水深测量中，合理地采集水深数据是确保高质量测图不可或缺的环节。为了高效合理采集水深数据，测量前的测线合理布设和测量中的航迹控制是两个关键点。本文提出了用于计划测线布设与航迹控制的算法，并对其进行了理论上的推导与分析，同时在新研制的水深数据采集系统中得以应用，证明以所提出的算法进行测线布设与航迹控制是有效的。     

基于Cressman优化算法的海洋矢量数据插值方法研究

随着海洋监测技术的发展,多源、异构、多维的海洋数据成指数激增。当前用于海洋数据的插值技术存在处理速度慢、读取效率低等问题,难以满足数据处理的需要。针对具有空间分布特性的海洋矢量数据,本文旨在研究一种高效的插值方法,首先基于Moran’s I对矢量数据进行空间相关性分析,根据数据间的聚类程度对数据集进行冗余度处理,然后基于Cressman插值算法对处理后的矢量数据进行插值展示。最后,以某区域的流场数据进行仿真,验证了基于Cressman插值优化算法的合理性和可行性。     

基于GPS的飞机航迹预测方法研究

简要介绍了GPS动态测量系统的组成及存在的缺陷。提出了采用滑窗多项式拟合方法进行航迹推算的数学模型,通过改变系统信息流向、重新组织下发数据报文结构等一系列技术措施来提高航路数据的拟合精度。仿真结果说明,该方法计算量小、速度快、精度高,利于飞机航迹的实时预测。     

提高航迹计算精度的方法研究

分析了传统的航迹计算方法存在的系统误差,引入了符号形式的子午线弧长正反解公式,推导出了可以消除该误差进而提高航迹计算精度的精确墨卡托航法。算例分析表明,该方法可以解决航海上不同地球参考椭球下的航迹计算问题,反解精度高达10^-4 m。     

海洋探测中HYPACK原始记录文件的数据提取和图形表达

HYPACK综合导航定位系统是广泛应用于海洋工程水下地形地貌测量的数据采集和处理软件,它支持多种定位设备和测深设备的数据采集和处理。如何正确提取所需的数据、满足不同工程测量的特殊要求,是我们在实际使用中经常碰到的问题。分析了实测HYPACK数据,以VISUAL C 6.0为平台进行程序开发,实现了在HYPACK记录的原始文件中特定数据的处理,如航迹(点位)坐标、水深值、潮位数据等。所开发的程序实现了数据的图形可视化和由数据向DXF格式的转换,实现了数据编辑和图形效果的交互。     

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。     

矢量地图数据的加密算法

加密技术是保障数据安全的最主要的手段，结合矢量地图数据的特点，设计了一种基于混沌序列的数据加密算法。实验证明，该算法加密效率高，保密性好。     

基于PS-VF-TBD的地波雷达船只目标航迹起始方法

针对地波雷达低信噪比目标信号"闪烁"导致的航迹起始困难问题,本文提出了一种基于PS-VF-TBD的航迹起始方法.该方法综合利用了地波雷达回波谱中目标信号的展宽特征和运动特性,利用PS-VF-TBD方法对运动目标能量有效积累的特点,提高对疑似目标多帧信号间的关联概率,进而提高对真实目标的搜索概率和航迹起始成功率.通过地波...     

基于ADO.NET的Shape地图矢量数据存储研究

以Shape格式矢量数据的结构特点、存储方式为基础,采用ADO.NET技术,实现了Shape格式地图矢量数据的数据集的转换和存储。为采用关系型数据库技术管理Shape格式数据以及建立Shape数据的空间拓扑关系提供了一种方法。     

中国近海地区热带气旋移向突然左折规律的研究

对１５例近海地区热带气旋移向突然左折的规律进行分析。结果表明热带气旋路径左折是由多种因素综合作用的结果。它与环流背景、流行征、变高场配置、云闭作用、双涡旋和冷空气等的影响均有密切关系。     

基于XML的海洋环境基础数据格式转换的研究

针对当前海洋科学研究、海洋预报、海洋环境保护等工作中遇到的海洋环境基础数据格式不一致的问题,通过对数据语义、语法、结构的分析,建立数据之间格式转换模型,在此基础上提出基于可扩展标记语言(XML)转换模板的数据格式转换体系,并以台站观测温盐数据为例,设计编写程序成功实现数据间的格式转换。     

LIC color texture enhancement algorithm for ocean vector field data based on HSV color mapping and cumulative distribution function

Texture-based visualization method is a common method in the visualization of vector field data. Aiming at adding color mapping to the texture of ocean vector field and solving the ambiguity of vector direction in texture image, a new color texture enhancement algorithm based on the Line Integral Convolution (LIC) for the vector field data is proposed, which combines the HSV color mapping and cumulative distribution function calculation of vector field data. This algorithm can be summarized as follows: firstly, the vector field data is convoluted twice by line integration to get the gray texture image. Secondly, the method of mapping vector data to each component of the HSV color space is established. And then, the vector field data is mapped into HSV color space and converted from HSV to RGB values to get the color image. Thirdly, the cumulative distribution function of the RGB color components of the gray texture image and the color image is constructed to enhance the gray texture and RGB color values. Finally, both the gray texture image and the color image are fused to get the color texture. The experimental results show that the proposed LIC color texture enhancement algorithm is capable of generating a better display of vector field data. Furthermore, the ambiguity of vector direction in the texture images is solved and the direction information of the vector field is expressed more accurately.     

一种基于深度学习的热带气旋路径集成预报方法

本文提出了一种基于深度学习的热带气旋(tropical cyclone,TC)路径集成预报方法.该方法以长短期记忆深度网络为模型构架,利用前4个时刻(24 h,间隔6 h)及当前时刻的TC路径记录,以及由不同环境因素所计算的方向预报因子作为输入,分别直接预报和间接(通过预报移动速度)预报路径,集成两者预报结果实现时效为...     

Study of tide prediction method influenced by nonperiodic factors based on support vector machines

Harmonic analysis, the traditional tidal forecasting method, cannot take into account the impact of noncyclical factors, and is also based on the BP neural network tidal prediction model which is easily limited by the amount of data. According to the movement of celestial bodies, and considering the insufficient tidal characteristics of historical data which are impacted by the nonperiodic weather, a tidal prediction method is designed based on support vector machine (SVM) to carry out the simulation experiment by using tidal data from Xiamen Tide Gauge, Luchaogang Tide Gauge and Weifang Tide Gauge individually. And the results show that the model satisfactorily carries out the tide prediction which is influenced by noncyclical factors. At the same time, it also proves that the proposed prediction method, which when compared with harmonic analysis method and the BP neural network method, has faster modeling speed, higher prediction precision and stronger generalization ability.     

Robust source localization in shallow water based on vector optimization

Owing to the multipath effect, the source localization in shallow water has been an area of active interest. However, most methods for source localization in shallow water are sensitive to the assumed model of the underwater environment and have poor robustness against the underwater channel uncertainty, which limit their further application in practical engineering. In this paper, a new method of source localization in shallow water, based on vector optimization concept, is described, which is highly robust against environmental factors affecting the localization, such as the channel depth, the bottom reflection coefficients, and so on. Through constructing the uncertainty set of the source vector errors and extracting the multi-path sound rays from the sea surface and bottom, the proposed method can accurately localize one or more sources in shallow water dominated by multipath propagation. It turns out that the natural formulation of our approach involves minimization of two quadratic functions subject to infinitely many nonconvex quadratic constraints. It shows that this problem (originally intractable) can be reformulated in a convex form as the so-called second-order cone program (SOCP) and solved efficiently by using the well-established interior point method, such as the software tool, SeDuMi. Computer simulations show better performance of the proposed method as compared with existing algorithms and establish a theoretical foundation for the practical engineering application.     

基于矢量瓦片技术的Web电子海图优化方法

传统的基于栅格瓦片技术生产的Web电子海图虽解决了跨浏览器显示的问题,但其显示速度、渲染效果及交互能力仍无法满足现在用户的需求。为了实现Web电子海图的大规模应用,针对栅格瓦片技术支持的下电子海图中存在的缺陷,提出基于开源地图服器Geoserver与地图可视化JS库Leaflet的矢量瓦片技术优化方案,包括海图数据预处理、矢量切片的制作、矢量瓦片数据多样式显示及矢量瓦片数据要素查询等,通过在实验室海洋信息展示平台中的验证与测试,实现了矢量电子海图数据在Web页面上的多样式灵活显示及交互功能,证实了优化方案的可行性及高效性,整体提升了Web海图服务的效率。     

基于矢量信号处理的水声定位系统

将传统的水声定位系统与矢量水听器相结合，设计了一种全新的轻便型长基线被动水声定位系统。介绍了系统的组成和工作原理，并结合近年来出现的矢量信号处理技术，设计了新的实时信号处理软件。经湖试和海试，系统的可行性得到了初步的验证。