Gradient slope, aspect slope, profiling and contourlines are important topographic parameters that can be derived from digital elevation data obtained from different sources with exploitation of different interpolatio...Gradient slope, aspect slope, profiling and contourlines are important topographic parameters that can be derived from digital elevation data obtained from different sources with exploitation of different interpolation techniques. Geostatistical interpolation methods such as ordinary kriging models constitute reliable alternatives to deterministic approaches in creation of continuous surface models from discrete elevation data. This research aimed at extraction, analysis, and evaluation of different terrain parameters elevation measurements with the use of different ordinary kriging models including the linear model, the circular model, the spherical model, the exponential models, and the Gaussian model. Different ordinary kriging models under ESRI ArcView 3.3 package along with its 3D analyst and Spatial analysis extensions have been exploited in extraction of gradient slope maps, aspect slope maps, and hillshade maps in addition to contourline maps from a sample of elevation data. Visual analysis of the gradient slope maps shows great similarities between the slope maps from the linear, circular, spherical, and exponential OK models, however, that from OK Gaussian models look very different as different sizes and arrangements of the colour patches, referring to different tones and different textures where smooth tones and smooth textures dominate the gradient slope map from the OK Gaussian model. Thus, gradient slope degradation and smoothing are considerably high in the gradient slope map from Gaussian model compared to the slope maps from the other four OK models. Also, the mean slope in the Gaussian model records the lowest value with the lowest value of the standard deviation of slopes in the same map reflecting less structured and highly smoothed gradient slope map compared to the slope maps from the other OK models. Thus, similar sizes of the colour patches and similar tones and similar texture dominate the different aspect slope maps. This is not the case in Figure 2(e) which depicts the aspect slope map展开更多
为了提高等值线生成率,高效直观地绘制衍射极图及其他相应等值线图,根据晶体结构数据的特点和对等值线绘制的要求,提出了一种基于网格序列法的等值线生成算法NSVD-GA(Grid Scan and Vertex Digit-al-Generation Algorithm of Contour Li...为了提高等值线生成率,高效直观地绘制衍射极图及其他相应等值线图,根据晶体结构数据的特点和对等值线绘制的要求,提出了一种基于网格序列法的等值线生成算法NSVD-GA(Grid Scan and Vertex Digit-al-Generation Algorithm of Contour Lines Drawing)。该算法基于网格序列采用对网格端点量化后进行数字比较的方法绘制等值线,既避免了网格无关法等值线追踪起始点选取困难、网格出口判断复杂的问题,又有效地减少等值线值与端点的判断次数。该算法思路清晰,简洁高效,非常适合晶体结构等科研数据的等值线图表达及其他类似情况的等值线生成。展开更多
文摘Gradient slope, aspect slope, profiling and contourlines are important topographic parameters that can be derived from digital elevation data obtained from different sources with exploitation of different interpolation techniques. Geostatistical interpolation methods such as ordinary kriging models constitute reliable alternatives to deterministic approaches in creation of continuous surface models from discrete elevation data. This research aimed at extraction, analysis, and evaluation of different terrain parameters elevation measurements with the use of different ordinary kriging models including the linear model, the circular model, the spherical model, the exponential models, and the Gaussian model. Different ordinary kriging models under ESRI ArcView 3.3 package along with its 3D analyst and Spatial analysis extensions have been exploited in extraction of gradient slope maps, aspect slope maps, and hillshade maps in addition to contourline maps from a sample of elevation data. Visual analysis of the gradient slope maps shows great similarities between the slope maps from the linear, circular, spherical, and exponential OK models, however, that from OK Gaussian models look very different as different sizes and arrangements of the colour patches, referring to different tones and different textures where smooth tones and smooth textures dominate the gradient slope map from the OK Gaussian model. Thus, gradient slope degradation and smoothing are considerably high in the gradient slope map from Gaussian model compared to the slope maps from the other four OK models. Also, the mean slope in the Gaussian model records the lowest value with the lowest value of the standard deviation of slopes in the same map reflecting less structured and highly smoothed gradient slope map compared to the slope maps from the other OK models. Thus, similar sizes of the colour patches and similar tones and similar texture dominate the different aspect slope maps. This is not the case in Figure 2(e) which depicts the aspect slope map
文摘为了提高等值线生成率,高效直观地绘制衍射极图及其他相应等值线图,根据晶体结构数据的特点和对等值线绘制的要求,提出了一种基于网格序列法的等值线生成算法NSVD-GA(Grid Scan and Vertex Digit-al-Generation Algorithm of Contour Lines Drawing)。该算法基于网格序列采用对网格端点量化后进行数字比较的方法绘制等值线,既避免了网格无关法等值线追踪起始点选取困难、网格出口判断复杂的问题,又有效地减少等值线值与端点的判断次数。该算法思路清晰,简洁高效,非常适合晶体结构等科研数据的等值线图表达及其他类似情况的等值线生成。
