基于ICESat/GLAS数据的中国典型区域SRTM与ASTER GDEM高程精度评价

航天飞机雷达地形测绘(shuttle radar topography mission, SRTM)和先进星载热发射和反射辐射成像仪全球数字高程模型(advanced spaceborne thermal emission and reflection radiometer global digital elevation model, ASTER GDEM)提供了全球覆盖面积最广的数字高程模型(digital elevation model, DEM)数据, 但其高程精度还未得到充分验证, 传统地面测量方法很难适用于验证大面积范围的DEM精度.以冰、云和陆地高程卫星/地学激光测高系统(ICESat/GLAS)高程数据为参考, 综合利用地理信息系统(geographic information system, GIS)空间分析、三维可视化与统计分析方法, 对中国典型低海拔沿海平原地区和高海拔山地的两种DEM数据高程精度进行了对比分析.结果表明, 高程值小于20m的低海拔地区, SRTM高程精度达到2.39m, ASTER GDEM的精度达到4.83m, 均远远高于这两种数据的标称精度; 而在西南山地, 这两种DEM的精度大约为20m, 与标称精度相当.最后, 建立了ICESat/GLAS与SRTM和ASTER GDEM的一元线性回归模型, 该模型具有较高的拟合度和显著线性关系, 可用于改善这两种DEM的高程精度. 

Vertical Accuracy Assessment of SRTM and ASTER GDEM over Typical Regions of China Using ICESat/GLAS

SRTM (shuttle radar topography mission) and ASTER GDEM (advanced spaceborne thermal emission and reflection radiometer global digital elevation model), the most accurate and available global DEM (digital elevation model) data, cover nearly the entire land surface of the earth. However, the precision of these DEM data has not been fully validated. This paper focuses on Chinese typical regions, aiming to verify the elevation precision of SRTM and ASTER GDEM based on ICESat / GLAS (ice, cloud, and land elevation satellite/geoscience laser altimeter system) elevation data by utilization of GIS (geographic information system) spatial analysis, 3D visualization and statistical analysis methods. The results show that SRTM elevation precision reaches 2.39m, and ASTER GDEM precision reaches 4.83m in the low altitude areas where the elevation value is less than 20m. The elevation precision is higher than the specified precision in both cases. However, the precision in Southwest study area is similar to the specified precision. The established linear regression model in the present study has high goodness of fit and significant correlation, but the applicability of the model needs further study.