摘要
海底地形数据是进行海洋科学研究、工程建设的重要数据源,水深信息作为海底地形数据的基础信息,反映了海底地形的起伏变化。因此,如何有效地处理水深数据成为海洋测绘的重点研究内容。为解决海量多波束测深数据的数据冗余问题,提出了一种顾及坡度和高程的多波束测深数据抽稀算法,能够兼顾数据抽稀的精度和地形特征点的保留。考虑到存在含有空洞、凹边界等局部空白区域的多波束测深数据,首先利用Alpha Shape算法提取测深数据局部空白区域的边界点;然后采用坡度和高程相结合的抽稀算法删除冗余点,得到抽稀结果。在实验区内,通过与基于坡度抽稀、顾及地形复杂度抽稀和基于系统抽稀算法进行对比实验,结果表明:(1)本文抽稀算法在测深数据局部空白区域生成的等深线较上述抽稀算法更贴近原始测深数据等深线的形态,可以有效保持地形形态完整性;(2)对不同地形的测深数据进行抽稀,本文算法的精度较上述抽稀算法均有不同程度的提升,尤其抽稀率较低时,本文算法较上述算法在MSE分别提升了16%、27%、14%和10%、36%、2%,RMSE分别提升了7%、12%、7%和5%、17%、3%,体现了本文算法对不同地形多波束测深数据抽稀的有效性和通用性,有效提高测深数据抽稀的精度,满足后续测深数据构建高精度海底地形的需要。
The submarine topographic data are important data source for marine scientific research and engineering construction.The bathymetric information,as the basic information of submarine topographic data,reflects the undulating changes of submarine topography.Therefore,how to effectively process bathymetric data has become a key research content of marine mapping.In order to solve the problem of data redundancy of massive multibeam bathymetry data,a multibeam bathymetry data thinning algorithm taking into account the slope and elevation is proposed,which can balance the accuracy of data thinning and the retaining of topographic feature points.Considering that the multibeam bathymetry data contain local blank areas such as cavities and concave boundaries,the Alpha Shape algorithm is first used to extract boundary points from the multibeam bathymetry data,so as to avoid the problem of losing terrain feature points due to thinning of the local bathymetry data blank areas.Then,a combination of slope and elevation thinning algorithms was used to delete redundant points and retain terrain feature points,and the boundary points of the thinned multibeam bathymetric data(containing local blank areas)are combined to obtain final thinning results.The accuracy is evaluated by using the checkpoint method.In the study area,the comparison experiments are carried out using the slope-based thinning,terrain complexity-based thinning,and system based thinning algorithms as references.The results show that:(1)The isobath derived from our proposed algorithm in the area containing local blank areas is closer to the isobath variation of the original bathymetric data compared to three reference thinning algorithms,and can more precisely express the fine features at the concave boundaries,hollows,and other areas and effectively maintain the morphological integrity of the seafloor topography;(2)The accuracy of the proposed algorithm is improved in different degrees compared with the reference thinning algorithms.Especially,as the thinning rate decreases,the Mean Square Error(MSE)of the proposed algorithm is decreased by 16%,27%,14%,and 10%,36%,2%,respectively in two kinds of terrain,and the Root Mean Square Error(RMSE)is decreased by 7%,12%,7%and 5%,17%,3%for two types of terrain,respectively,which demonstrates the effectiveness and generalizability of the proposed algorithm for thinning of multibeam bathymetric data in different types of terrains,improving the accuracy of bathymetric data thinning effectively,and meeting the needs of subsequent bathymetric data construction of high-precision seafloor topography.
作者
齐林君
翟仁健
李安平
QI Linjun;ZHAI Renjian;LI Anping(Information Engineering University,Geospatial Information Institute,Zhengzhou 450001,China;78098 Troops,Chengdu 610000,China)
出处
《地球信息科学学报》
CSCD
北大核心
2023年第1期142-152,共11页
Journal of Geo-information Science
基金
国家安全重大基础研究项目(613317)。
关键词
多波束测深数据
DELAUNAY三角网
抽稀
地形特征
数据处理
multibeam sounding data
Delaunay triangulation network
thinning algorithm
topographic features
data processing