Abstract

Defining watersheds with enough topographical features is crucial when large infrastructure projects are concerned. German Aerospace Center (DLR) recently announced the dissemination of the 90 m variant of the original global TanDEM-X 12 m Digital elevation model (DEM). It was announced as produced with a special averaging technique, which would even surpass the precision of the 12 m DEM. This study aimed to test this claim while simultaneously testing whether resolution coarsening would deteriorate the performance of a higher precision DEM. AW3D30 was used as auxiliary data in four sites. Results confirmed that the 90 m DEM was indeed highly reliable at or below 20% slopes in two investigated dam reservoir areas with gentle terrain conditions, and overestimated in other two dam reservoirs with severe topography. The resampling approach did not necessarily worsen the elevation values aggregated into a larger raster resolution as obvious from the auxiliary data analyses.

摘要

当涉及大型基础设施项目时，定义具有足够地形特征的流域至关重要。德国航空航天中心 (DLR) 最近宣布发布原始全球 TanDEM-X 12 m 数字高程模型 (DEM) 的 90 m 变体。它被宣布采用特殊的平均技术生产，其精度甚至超过了 12 m DEM 的精度。本研究旨在测试这一说法，同时测试分辨率粗化是否会降低更高精度 DEM 的性能。AW3D30 被用作四个站点的辅助数据。结果证实，在两个地形条件温和的调查大坝水库区，90 m DEM 在 20% 或低于 20% 坡度处确实高度可靠，而在其他两个地形恶劣的大坝水库中被高估。