摘要
作为多学科交叉与渗透产物的数字高程模型(DEM)已在诸多学科和领域及实际应用中发挥了重要作用,但目前能够免费获取的高分辨全球DEM在不同区域仍存在很大的不确定性,应用之前进行质量评估至关重要。以烟台市为实验区,以大比例尺地形图(1∶10 000)生成的DEM为参照,结合坡度、坡向和土地覆被类型等地学因子,定量分析了目前广泛应用的两个版本ASTER GDEM(先进星载热辐射和反射辐射计全球数字高程模型)ASTETR 1和ASTER 2及不同空间分辨率SRTM DEM(航天飞机雷达地形测绘任务)(SRTM 1:～30m和SRTM 3:～90m)在低山丘陵区高程、坡度及坡向误差。结果表明:在研究区域内,ASTER 1、ASTER 2、SRTM 3、SRTM 1总体高程均方根误差分别为8.7m、6.3m、3.7m和2.9m。ASTER与SRTM的高程精度不同程度地受坡度、坡向以及土地覆被类型等地学因子的影响,DEM误差随坡度增加而增大,其中SRTM 3精度对该因子最敏感。尽管坡向对DEM精度影响不明显(4种DEM在不同坡向上的均方根误差波动范围均不超过2m),但是不同土地覆被类型下这4种DEM精度差异显著。此外,分析4种DEM提取的坡度可知,SRTM 1的均方根坡度误差最低(2.5°)、ASTER 1与ASTER 2的坡度的均方根误差大致相同(3.6°、3.9°)、SRTM 3的坡度均方根误差最高(4.3°)。坡向的精度SRTM 1最高,ASTER 1与ASTER 2次之,SRTM 3最低。研究结果对我国低山丘陵区ASTER GDEM与SRTM DEM的应用与精度评估具有一定的借鉴作用。
As an interdisciplinary product,the Digital Elevation Model (DEM) plays an important role in many fields,disciplines and practical applications.However,it’s essential to evaluate DEM’s quality before application because high-resolution global DEM that is currently available for free is still highly uncertain over different areas.The errors of the two versions of Advanced Spaceborne Thermal Emission and Reflection Radiometer Global (ASTER) Digital Elevation Model (ASTER 1 and ASTER 2) and different resolution Shuttle Radar Topography Mission (SRTM ) DEM (SRTM 1:~30 m and SRTM 3:~90 m) are quantitatively evaluated in comparison with 1∶10 000 DEM over Yantai City which is dominated by low mountain and hilly land.Basic geomorphometric factors such as slope,aspect and land cover influencing the errors of ASTER GDEM and SRTM DEM are investigated.The overall vertical accuracy (indexed by RMSE) is estimated to be 8.7 m,6.3 m,3.7 m and 2.9 m for ASTER 1,ASTER 2,SRTM 3and SRTM 1,respectively.Despite much improvement of ASTER 2 in relative to ASTER 1,stripes anomalies still occur in mountainous terrain for ASTER 2.These DEM errors increase with the increase of slopes.In particular,vertical accuracy of SRTM 3 is the most sensitive to the slope changes.Although the elevation accuracy is similar over the different slope directions,the performance of these four DEMs are related to the land cover types,with higher accuracy over wetland farmland than woodland and grassland.The slope RMSEs for SRTM 1,SRTM 2,ASTER 1 and ASTER 2 are 2.5°,4.3°,3.6° and 3.9°,respectively.In terms of the aspect accuracy,SRTM 1 is highest,following by ASTER 1 and ASTER 2 are second,and SRTM 3is lowest.These results provide important bench mark for the application of ASTERG DEM and SRTM DEM in the low mountain and hilly areas of China.
作者
张玉伦
王叶堂
Zhang Yulun;Wang Yetang(College of Geography and Environment,Shandong Normal University,Ji'nan,250014,China)
出处
《遥感技术与应用》
CSCD
北大核心
2018年第6期1112-1121,共10页
Remote Sensing Technology and Application
基金
国家自然科学基金项目(41576182)
国家重大科学计划项目(2013CBA01804)
山东省省属高校优秀青年基金项目(ZR2016JL030)共同资助
关键词
多源DEM
低山丘陵区
误差分析
Multi-resource DEM
Error analysis
Low mountain and hilly areas
