反距离加权插值参数对细沟DEM精度的影响  

Impact of Inverse Distance Weighted Interpolation Parameterson Rill DEM Accuracy

作　　者：赵亚凯 邓青春[1,2,3] ZHAO Ya-Kai;DENG Qing-Chun(School of Geographical Sciences,China West Normal University,Nanchong Sichuan 637009,China;Sichuan Provincial Engineering Laboratory of Monitoring and Control for Soil Erosion on Dry Valleys,China West Normal University,Nanchong Sichuan 637009,China;Liangshan Soil Erosion and Ecological Restoration in Dry Valleys Observation and Research Station,Xide Sichuan 616753,China)

机构地区：[1]西华师范大学地理科学学院,四川南充637009 [2]西华师范大学四川省干旱河谷土壤侵蚀监测与控制工程实验室,四川南充637009 [3]大小凉山干旱河谷土壤侵蚀与生态修复野外科学观测研究站,四川喜德616753

出　　处：《西华师范大学学报（自然科学版）》2023年第5期496-504,共9页Journal of China West Normal University(Natural Sciences)

基　　金：国家自然科学基金项目(41971015);西华师范大学校级基金项目(19E067)。

摘　　要：以元谋干热河谷地区细沟为例,采用近景摄影测量方法获取细沟点云数据,测针板法获取细沟横剖面数据。通过改变反距离加权插值算法中的幂函数、相邻点数、搜索形状、搜索扇区等参数构建细沟DEM,运用验证数据集方法以及细沟横剖面数据对比法检验评价DEM插值精度。结果表明:(1)幂函数P值为3或4时,构建DEM精度最佳;(2)当相邻点数为10~12个时,各项误差均较小;(3)当搜索形状为椭圆形30°,长短半轴比例为4∶1时构建DEM精度最佳;(4)四扇区搜索为最佳搜索方式,但搜索扇区也是各项参数中影响因子最小的参数;(5)采用测针板法获取细沟横剖面,虽然局部由于测量误差出现异常值,但总体结果较优,与探究的反距离加权插值最佳参数构建DEM的横剖面误差值在2 cm左右。Taking the rill in the dry-hot valley area of Yuanmou as an example,the rill point cloud data is obtained by the close-up photogrammetry method and the rill cross-section data is obtained by the stylus plate method.The rill DEM is constructed by changing the parameters of power function,adjacent points,search shape,search sector and other parameters in IDW,and the DEM interpolation accuracy is tested and evaluated by the verification method of data set and the comparison method of rill cross-section data.The results are as follows:(1)When the P value of power function is 3 or 4,the accuracy of constructing DEM is the best;(2)When the number of adjacent points is 10~12,the overall errors are smaller;(3)When the search shape is 30°elliptical neighborhood and the ratio of length and short half axis is 4∶1,the accuracy of constructing DEM is the best;(4)The four sectors search is the best search method,but the search sector is also the parameter with the smallest impact;(5)When the stylus plate method is employed to obtain the rill cross section,there are outliers due to the measurement error,but the overall results are comparatively excellent,and the cross-section error value of constructing DEM with the best parameter of IDW is about 2 cm.

关 键 词：反距离加权插值 细沟 DEM 近景摄影测量 

分 类 号：P208[天文地球—地图制图学与地理信息工程]