TanDEM-X IDEM precision and accuracy assessment based on a large assembly of differential GNSS measurements in Kruger National Park, South Africa
TanDEM-X IDEM precision and accuracy assessment based on a large assembly of differential GNSS measurements in Kruger National Park, South Africa
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DOI：
10.1016/j.isprsjprs.2016.05.005
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发表时间：
2016-09-01
影响因子：
12.7
通讯作者：
Schmullius, C.
中科院分区：
文献类型：
--
作者：
Baade, J.;Schmullius, C.
高分辨率的数字高程模型（DEM）代表了广泛的地球表面过程研究的基础数据。在过去几年中，德国TanDEM-X使命获得了一个新的，真正的全球数字高程模型的数据，具有前所未有的几何分辨率，精度和准确性。2014年11月，第一批几何分辨率为0.4至3角秒的TANDEM中间数字高程模型（即IDEM）已可用于科学目的。这包括覆盖南非克鲁格国家公园的四个1度x 1度瓷砖。在这里，我们记录了当地规模的IDEM高度精度验证工作的结果，利用超过10,000 RTK-GNSS为基础的地面测量点，从14个网站的特点主要是原始稀树草原植被。地面检查站的垂直精度为0.02 m（1 sigma）。为便于比较，分析中包括了选定的前兆数据集（SRTMGLI、SRTM 41、ASTER-GDEM 2）。虽然IDEM代表了新的全球TanDEM-X DEM（预计将于2016年底发布）的中间产品，但它使我们能够首次深入了解即将推出的产品的特性。值得注意的是，TanDEM-X切片包括许多辅助文件，提供与基于用户的质量评估相关的详细信息。我们提出的例子，利用这些信息的框架内的当地规模的研究，包括识别高度读数污染的水。此外，这项研究提供了证据的高精度和准确度的IDEM高度读数和冠层覆盖的敏感性。对于开阔地形，0.4弧秒分辨率版本（IDEM 04）产生的平均偏差为0.20 +/- 0.05 m（95%置信区间，Cl 95），RMSE = 1.03 m，绝对垂直高度误差（LE 90）为1.5 [1.4，1.7] m（Cl 95）。较低分辨率的IDEM版本的相应值大致相同，这证明了不同分辨率级别的IDEM产品的高质量。与选定的前体DSM相比，TanDEM-X提供的高程数据不仅几何分辨率高出2.5倍，垂直精度高出5-10倍，明显优于LE 90
High resolution Digital Elevation Models (DEM) represent fundamental data for a wide range of Earth surface process studies. Over the past years, the German TanDEM-X mission acquired data for a new, truly global Digital Elevation Model with unprecedented geometric resolution, precision and accuracy. First TanDEM Intermediate Digital Elevation Models (i.e. IDEM) with a geometric resolution from 0.4 to 3 arc sec have been made available for scientific purposes in November 2014. This includes four 1 degrees x 1 degrees tiles covering the Kruger National Park in South Africa. Here, we document the results of a local scale IDEM height accuracy validation exercise utilizing over 10,000 RTK-GNSS-based ground survey points from fourteen sites characterized by mainly pristine Savanna vegetation. The vertical precision of the ground checkpoints is 0.02 m (1 sigma). Selected precursor data sets (SRTMGLI, SRTM41, ASTER-GDEM2) are included in the analysis to facilitate the comparison.Although IDEM represents an intermediate product on the way to the new global TanDEM-X DEM, expected to be released in late 2016, it allows first insight into the properties of the forthcoming product. Remarkably, the TanDEM-X tiles include a number of auxiliary files providing detailed information pertinent to a user-based quality assessment. We present examples for the utilization of this information in the framework of a local scale study including the identification of height readings contaminated by water. Furthermore, this study provides evidence for the high precision and accuracy of IDEM height readings and the sensitivity to canopy cover. For open terrain, the 0.4 arcsec resolution edition (IDEM04) yields an average bias of 0.20 +/- 0.05 m (95% confidence interval, Cl95), a RMSE = 1.03 m and an absolute vertical height error (LE90) of 1.5 [1.4, 1.7] m (Cl95). The corresponding values for the lower resolution IDEM editions are about the same and provide evidence for the high quality of the IDEM products across the different resolution classes. Compared to the selected precursor DSMs, TanDEM-X will provide elevation data not only with up to 2.5 times higher geometric resolution and a 5-10 times higher vertical accuracy clearly outperforming the LE90