边界搜索下的水深数据抽稀算法设计与实现

发布时间：2018-02-09 01:00

本文关键词： 边界搜索抽稀比例尺阈值　出处：《武汉大学》2017年硕士论文　论文类型：学位论文

【摘要】：多波束测深系统的不断进步和广泛应用,给海洋测绘带来了极大的便利。海洋测绘从单波束系统测量转变为多波束系统测量,测量精度和测量效率都得到了大大的提高。但是多波束测深系统存在着另外一些问题,多波束的测量大大增加了单位面积的水深点数据个数,大范围的测量海域决定了水深数据的海量特性,而且水深数据由于重叠测量,存在着大量的数据冗余。北方海域某测区的水深数据经过长年积累,具有海量的特性而且多时相的特点,如何对原始海量的水深数据进行抽稀,删除冗余的水深数据,保留最新的且可用的水深数据,且根据比例尺建立不同层次的水深数据库,成为解决水深数据问题的关键。本文对比多种数据抽稀算法,提出一种基于边界搜索的水深数据抽稀算法,首先提取水深数据点集的凸壳,然后凸壳逐步内缩,形成点集的边界,最后根据水深数据抽稀规则对边界内的水深数据进行抽稀,保留时间最新的数据点和深度最浅点,并建立三维海底地形模型。通过对多种算法进行数据抽稀实验,并对比抽稀结果、抽稀效率和三维模型的生成,该算法大大提高了水深数据抽稀的效率和准确率,在大量减少数据冗余的同时,而且能够很好的保留海底地形特征。同时,该算法可以应用到水深数据的组织管理维护上,根据不同的比例尺下的不同抽稀阈值,使水深数据分层为不同比例尺的水深数据库,便于海事部门生产满足不同比例尺的海图需求和不同层次的航海需要。最后应用该算法处理某海事部门的水深数据,抽稀水深数据,并建立水深数据库和水深数据更新机制,该算法为水深数据的抽稀和水深数据库的建立提供了有效的方法。
[Abstract]:The continuous progress and wide application of multi-beam bathymetric system bring great convenience to marine surveying and mapping. Marine surveying and mapping has changed from single-beam system to multi-beam system. The measurement accuracy and efficiency have been greatly improved, but there are some other problems in the multi-beam bathymetric system. The multi-beam measurement greatly increases the number of water depth point data per unit area. The massive characteristics of the bathymetric data are determined by the large range of measured sea areas, and there is a great deal of data redundancy due to the overlapping surveying of the bathymetric data. The bathymetric data of a certain area in the northern sea area have accumulated over the years. It has the characteristics of magnanimity and multiphase, how to dilute the original massive water depth data, delete redundant water depth data, keep the latest and available depth data, and establish different levels of water depth database according to the scale. In this paper, a new algorithm based on boundary search is proposed to extract the convex hull of the point set of water depth data, and then gradually shrink the convex shell. Forming the boundary of the point set, finally thinning the water depth data within the boundary according to the rules of water depth data extraction, keeping the newest data points and the shallowest depth points. The 3D submarine terrain model is established. Through the data thinning experiment of many algorithms and the comparison of thinning results, drawing efficiency and the generation of 3D model, the algorithm greatly improves the efficiency and accuracy of water depth data thinning. At the same time, the algorithm can be applied to the management and maintenance of water depth data, according to the different drawing threshold under different scales. In order to make the depth data stratified into different scale bathymetric databases, it is convenient for maritime departments to meet the needs of nautical charts of different scales and different levels of navigation. Finally, the algorithm is applied to deal with the depth data of a certain maritime department. The algorithm provides an effective method for the extraction of water depth data and the establishment of water depth database.
【学位授予单位】：武汉大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P229

【参考文献】