共查询到18条相似文献,搜索用时 171 毫秒
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本文主要介绍基于GIS栅格数据计算最优道路路线问题的算法设计原理和实现方法,本算法有自己独特的特点,它主要是根据坡度分级费用、最大坡长、最大纵坡和选线范围等限制条件,运用费用栅格矩阵法计算最优道路路线。本文最后给出一个示例,以验证道路选线模型计算结果的正确性。 相似文献
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DEM生成中面状河流区域DEM格网点高程应与所在水域面高程保持一致,这一问题目前尚没有一个好的解决方法。根据地形图中等高线与河流水域面特殊空间关系特性,提出了基于高差分块的河流区域DEM格网点高程自动赋值方法。该方法采用河流水域面裁剪等高线,然后对分块多边形自动构面,自动提取分块区域高程,最后对分块区域DEM格网点高程自动赋值。实践表明该方法处理后的DEM数据比未经处理的DEM更符合河流水域面地表形态,精度更高,具有良好的实用性和可靠性。 相似文献
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李含璞 《测绘与空间地理信息》2021,44(10):183-188
数字高程模型(DEM)作为地面高程信息的数字表示形式,在地学研究领域得到了广泛应用.本文通过对DEM基本原理及其现有表示形式进行分析,提出了数字等高线也是DEM表示形式的观点.随后通过选取4种不同地貌类型的规则格网DEM作为实验区,分析研究了DEM格网间距对坡度、坡面曲率、地表切割深度、地表粗糙度和沟谷密度等地形因子提取的影响,为人们根据地貌类型和应用需求合理选择DEM分辨率提供了参考. 相似文献
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Digital elevation models (DEMs) and their derived parameters play an important role in geosciences. When upscaling, the influence of the upscaling procedure on the accuracy of DEMs' derived parameters has not been systematically studied. In this study, slope is taken as an example to explore the effect of upscaling procedure on the accuracy of DEMs' derived parameters. The meaning of upscaling is converting the data from finer resolution to coarser resolution. The two upscaling procedures of EES (elevation to elevation first, then elevation to slope) and ESS (elevation to slope first, then slope to slope) combined with four aggregation rules of maximum, mean, median, and minimum were used to obtain the slope result at the desired resolution in plain, hill, and mountain areas. From the experimental results, it can be concluded that the upscaling procedure significantly affected slope accuracy at the desired resolution. To obtain the slope result with higher accuracy during upscaling, it was recommended that the upscaling procedure of ESS combined with the mean or median aggregation rule was adopted whatever the terrain complexity. This study can be applied for the selection of upscaling procedure and aggregation rule in the upscaling of slope and it warns us to pay more attention to the upscaling procedure when obtaining the DEM‐derived parameters at multi‐resolutions. 相似文献
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实际地形一般是连续变化的。根据数字高程模型(Digital Elevation Model,DEM)自动绘制的等高线由折线段相连而成,需要进一步平滑,以便更准确地描绘出实际地形的分布。结合分段三次多项式与Akima法来对等高线进行平滑处理。实验证明该方法效率高,结果满意,达到较好的平滑效果。 相似文献
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探讨了道路施工造成的路域DEM变化区域的精细DEM建模方法。该方法首先把二维道路设计成果处理成三维的特征线要素,构建初始TIN;其次应用统计分析的方法内插求出实测点云中各点在初始TIN上的高程和实测高程之间的差异进行统计分析,验证并修改失真的三维特征线要素;然后与选取的少量地面观测点云构建变化区域的DEM,最终实现了路域变化区域精细DEM的构建方法。以杭瑞高速毕都(毕节至都格)段的道路设计成果和局部三维激光扫描数据为例开展了试验研究,研究表明该方法建立的路域DEM精度高、成本低、观测方式灵活,可广泛推广应用。 相似文献
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A. Östman 《The Photogrammetric Record》1987,12(69):333-341
The object of this paper is to study the geometric accuracy of photogrammetrically sampled digital elevation models (DEMs)obtained by using an on line graphical DEM editor. As a reference, DEMs obtained by regular grid measurements have been used. Three different test areas are used in the study, each representing different ground types and degrees of homogeneity. The DEMs have been evaluated with respect to their standard errors in elevation, slope and curvature. The results show that the standard errors are not improved by using the on line DEM editor. It is also demonstrated that an increased point density decreases the standard error in elevation while its effect on the standard error in slope is limited. The standard error in curvature is almost independent of the point density. 相似文献
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针对数字高程模型(digital elevation model,DEM)数据的多尺度表达问题,根据DEM格网数据在能量谱密度中“低频-高能-大尺度”的对应关系,在化简中关联地形语义特征,构建了DEM数据的多尺度表达模型。实验结果表明,该模型可以实时动态派生不同尺度下的DEM数据,通过等高线放样观察发现,该模型派生的DEM数据满足地形表达、空间认知和制图综合中的“保留主要地形特征、舍弃次要地形特征”的基本原则。与常用的DEM化简方法进行高程值统计以及坡形变化的定量对比分析,结果表明该方法在统计意义与结构意义上都具有较好的效果。 相似文献
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In this study, we present a newly developed method for the estimation of surface flow paths on a digital elevation model (DEM). The objective is to use a form‐based algorithm, analyzing flow over single cells by dividing them into eight triangular facets and to estimate the surface flow paths on a raster DEM. For each cell on a gridded DEM, the triangular form‐based multiple flow algorithm (TFM) was used to distribute flow to one or more of the eight neighbor cells, which determined the flow paths over the DEM. Because each of the eight facets covering a cell has a constant slope and aspect, the estimations of – for example – flow direction and divergence/convergence are more intuitive and less complicated than many traditional raster‐based solutions. Experiments were undertaken by estimating the specific catchment area (SCA) over a number of mathematical surfaces, as well as on a real‐world DEM. Comparisons were made between the derived SCA by the TFM algorithm with eight other algorithms reported in the literature. The results show that the TFM algorithm produced the closest outcomes to the theoretical values of the SCA compared with other algorithms, derived more consistent outcomes, and was less influenced by surface shapes. The real‐world DEM test shows that the TFM was capable of modeling flow distribution without noticeable ‘artefacts’, and its ability to track flow paths makes it an appropriate platform for dynamic surface flow simulation. 相似文献