摘要
利用栅矢转换和掩膜技术及ArcGIS的空间插值模块,构建了一种SRTM缺失数据的修复处理方法。通过不同条件下的多种样本试验,探讨了外界因素对插值精度和运算效率的影响。结果表明样条函数法是适宜于SRTM缺失数据修复的最佳插值方法。当人工模拟的空洞窗口大小为4×4像元时,其插值的误差平均值和标准差分别为0.90%和0.75%。随着地形起伏程度的增加,插值误差的平均值和标准差也随之加大。同时插值的精度会随着空洞窗口的增大而降低,窗口大小从4×4像元增大至12×12像元时,误差平均值从0.92%增加至3.84%,标准差则从0.75%增加至3.26%。试验表明6×6像元的窗口大小是保障插值误差在SRTM数据精度范围内的最大窗口。
The digital elevation data of Shuttle Radar Topography Mission（SRTM）is an important foundation data for geospatial modeling.However the void data of SRTM caused by the deficiencies of radar produce great inconvenience for its application.An approach and process flow of SRTM void data recovery is constructed using raster to vector conversion and mask processing technology based on spatial interpolation in ArcGIS software.To ensure the validity of interpolation results,the most important step of this process flow is deleting points of void data.The interpolation accuracy and operations efficiency of Inverse Distance to a Power（IDW）,Kriging,Nearest Neighbor（NN）and Spline are compared and analyzed based on a variety of test samples under different conditions.16 test samples of 4×4 pixel window size distribute on different landforms regions,while 12 test samples of different pixel window size from 1×1 to 12×12 locate on the same landforms region.The hollows of SRTM void data are simulated artificially through fill some negative value to the SRTM data in the areas of test samples.With this way to obtain the true value used to estimate interpolation accuracy.The mean of interpolation error is in decreasing order is IDW,NN,Krging and Spline,whose value is 1.32%,1.13%,1.07% and 0.90% respectively.Their standard deviation value are 0.90%、0.81%、0.62% and 75% respectively.Results show that Spline interpolation method is the optimal one applicable to recover void data of SRTM.When the artificial simulation window size of empty area is 4×4 pixels,the mean and standard deviation of interpolation error is 0.90% and 0.75% respectively.With the levels of undulating topography increase,the mean and standard deviation of interpolation error will increase accordingly.On the other hand,interpolation accuracy will descend with the accretion of window size.When the window size of empty area increase form 4×4 pixels to 12×12 pixels,the mean of interpolation error increased from 0.92% to 3.84%,standard deviation incr
出处
《城市勘测》
2011年第1期5-10,共6页
Urban Geotechnical Investigation & Surveying
基金
中国博士后科学基金(20080430586)
大洋生物资源开发与利用重点实验室开放基金(B-8208-07-0001-1)
