不同地貌下国产资源三号测绘卫星DSM数据质量评价——以云南省高海拔山区为例

Evaluation of DSM Data Quality on ZY-3 Surveying and Mapping Satellite in Different Terrain Type——A Case of High Altitude Mountain Areas in Yunnan

为了评价不同地貌下国产资源三号测绘卫星DSM数据精度,以云南省高海拔山区为研究案例,并以1：10 000实测地形图DEM为假定真值,以90 m分辨率SRTM DEM为评价参考,从高程精度和地形描述精度两个指标对15 m分辨率的ZY-3 DSM进行精度评价。结果表明：在不同地貌下ZY-3 DSM的高程精度和地形描述精度都优于SRTM DEM。从高程中误差分析来看,台地地貌精度最高,ZY-3 DSM高程中误差仅为SRTM DEM的1/6,平原地貌精度最低,该比值为1/2;就地形描述评价而言,四种地貌下ZY-3 DSM的Et均方根误差实际值与理论值均非常接近,实际值与理论值的比在0.975 2-1.594 3之间,而SRTM DEM在5.310 1-8.749 4之间。由此看来,不同地貌下ZY-3 DSM数据精度整体高于SRTM DEM。

In order to evaluate the accuracy of DSM data of ZY-3 Surveying and Mapping Satellite under different topography, this paper selects ZY-3 DSM data in the high altitude mountain areas, treats the field surveying data DEM and SRTM DEM as reference, and compares the data accuracy with field surveying data in terms of elevation accuracy and accuracy of terrain representation. The results show that, ZY-3 DSM is better than SRTM DEM both in the elevation accuracy and the accuracy of terrain representation,. From the view of the elevation accuracy, different topography has the same conclusion, although the data shows a little difference, and ZY-3 DSM performs the best in the mesa landforms. As for the accuracy of terrain representation, ZY-3 DSM is closer to the theoretical value. Compared to the theoretical value, with its RMS Et actual value, the final ratios are between 0.9572 and 1.5943, while the SRTM DEM are from 5.3101 through 8.7494. In words, the data accuracy of ZY-3 DSM is better than the SRTM DEM in different topography.