三维缓冲体分析是地理信息系统中广泛使用的空间分析功能,对水下潜航器地形匹配导航、海底工程建设规划、海底污染源扩散分析等水深测量研究领域具有重要意义.针对传统缓冲面构建算法在不规则三角网数字水深模型(trian-gulated irregular network digital depth model,TIN-DDM)精度及建模效率等方面存在的应用局限,以精度阈值可控的滚动球加速优化模型为分析对象,提出了一种基于关键采样点高效判定的TIN-DDM缓冲面快速构建算法.主要研究内容为:(1)在论证关键采样点备选点集空间分布特性的基础上,对临界滚动球半径的数值收敛趋势进行分析,设计了面向邻近备选点选取的临界滚动球半径试探迭代策略,给出了关联数据链记录高效构建的关键采样点判定准则;(2)将空间数据块索引建模应用于邻近备选点的快速定位,建立了空间索引快速定位的关键采样点高效判定模型,实现了对TIN-DDM缓冲面的快速构建.实验结果表明,针对海量TIN-DDM数据,所提算法可在保证缓冲面构建精度的基础上有效提高缓冲面的构建效率,降低整体缓冲面构建的时间复杂度.
Fast Construction Algorithm of TIN-DDM Buffer Surface Based on Efficient Determination of Key Sampling Points
Objectives:Three dimensional buffer analysis is a spatial analysis function widely used in geo-graphic information systems,which is of great significance in underwater submersible terrain matching navi-gation,submarine engineering construction planning,submarine pollution source diffusion analysis and other bathymetric research fields.The traditional buffer surface construction algorithm has limitations in the appli-cation of triangulated irregular network digital depth model(TIN-DDM)model accuracy and modeling effi-ciency.Therefore,taking the rolling ball acceleration optimization model with controllable accuracy threshold as the analysis object,we propose a fast TIN-DDM buffer surface construction algorithm based on the effi-cient determination of key sampling points.Methods:The main research contents are as follows:(1)Based on the spatial distribution characteristic analysis of alternative point sets,through the numerical conver-gence analysis of the critical rolling ball radius,the trial iteration strategy of critical rolling sphere radius is designed,then a new criterion for determining key sampling points is given.(2)The spatial data block index modeling is applied to the rapid positioning of adjacent alternative points,and an efficient judgment model of key sampling points for rapid positioning of spatial index is established.Results:From the statistical re-sults of the key data link list parameters and the actual buffer surface construction images,the proposed method can be used to build the buffer surface,and is consistent with the construction accuracy of the rolling ball accelerated optimization model.From the results of buffer surface construction time consuming of dif-ferent TIN-DDM water depth data,the time consuming of this method is obviously better than that of the rolling ball accelerated optimization model.Conclusions:The experimental results show that in the face of massive TIN-DDM data,the proposed algorithm can effectively improve the construction efficiency of buf-fer surface on the basis of ensuring the construction accuracy of buffer surface,and reduce the time complexity of overall buffer surface construction.
key sampling pointscritical rolling sphere radiusbuffer surface constructionTIN-DDM
万方数据
维普
