不同源DEM数据在高山区重力中区地形改正中的适用性

The applicability of different sources DEM data in median region terrain correction of gravity in high mountain areas

以青海省夏日哈木矿区作为高山试验区,利用航摄高精度1∶2000DEM数据对1∶5万DEM数据、AsterDEM数据和PleiadesDEM数据进行垂直精度比较分析,并对这3种数据在高山区复杂地形条件下重力中区地形改正中的适用性进行研究。结果表明在高山区这种复杂地形条件下,3种DEM数据的精度从高到低依次为PleiadesDEM、1∶5万DEM和AsterDEM;PleiadesDEM数据在1∶5万或更小比例尺重力中区地形改正中具有较好的适用性,1∶5万DEM数据在1∶20万或更小比例尺重力中区地形改正中具有较好的适用性,而AsterDEM不能满足1∶20万或更大比例尺重力中区地形改正的精度要求。

Taking the Xiarihamu mining area in Qinghai Province as an alpine experimental area,the authors used the high-precision1 ∶2,000 DEM data to make a comparative analysis of the vertical accuracy of1 ∶50,000 DEM data,Aster DEM data and Pleiades DEM data as well as the applicability of these data in median region terrain correction of gravity under the complex terrain conditions such as high mountain areas.The results show that the accuracy of Pleiades DEM is the highest,that of1 ∶50,000 DEM possesses the second place, and hat of Aster DEM is the lowest under the complex terrain conditions of high mountainous area.The Pleiades DEM data have good applicability in median region terrain correction of gravity scale of1 ∶50,000 or less,and the1 ∶50,000 DEM data have good applicability at a scale of1 ∶200,000 or less,but the Aster DEM cannot meet the accuracy requirements at a scale of1 ∶200,000 or more.