对ASTER GDEM数字高程模型的精度评价及修正

Accuracy Evaluation and Correction of ASTER GDEM Terrain Data

针对ASTER GDEM高程精度还未得到充分验证,以江西省莲花县为试验区,使用ICESat-2数据系统分析了ASTER GDEM在坡度、地形起伏度和土地利用类型中的误差分布。结果表明,ASTER GDEM受坡度、地形起伏度影响严重,随坡度、地形起伏度增加,GDEM误差呈上升趋势;对于不同土地利用类型,GDEM误差存在较大差异,在水域误差最大,在建设用地误差最小。最后,使用后向传播神经网络(BPNN)对莲花县ASTER GDEM修正,结果发现BPNN模型可以有效改善其高程精度。

The advanced spaceborne thermal emission and reflection radiometer global digitial elevation model(ASTER GDEM)is widely used in many fields with its high precision,high coverage,and free use.However,its elevation accuracy has not been fully verified.This paper took Lianhua County in Jiangxi Province as the test area and analyzed the error distribution of ASTER GDEM in slope,topography relief and land use type using the newly released ICESat-2 altimetry data.The results showed that ASTER GDEM elevation accuracy was about 14.1 m,which was better than its nominal accuracy of 20 m.ASTER GDEM was seriously affected by slope and topography relief.With the increase of slope and topography relief,the error of ASTER GDEM basically showed an upward trend.For different land use types,the error of ASTER GDEM was quite different,and the error in the water area was the largest,the smallest error in construction land.Finally,an artificial neural network(ANN)was used to correct the ASTER GDEM data in Lianhua County,and it was found that the ANN model could effectively improve the ASTER elevation accuracy.