How complementary are SRTM-X and -C band digital elevation models?
How complementary are SRTM-X and -C band digital elevation models?
复制标题
DOI：
10.14358/pers.72.3.261
复制
发表时间：
2006-03-01
影响因子：
1.3
通讯作者：
Walter, D
中科院分区：
文献类型：
--
作者：
Hoffmann, J;Walter, D
从C波段和X波段干涉雷达数据出发，建立了两种不同的数字高程模型(DEM)。虽然这两个DEM共享它们的几个属性，但它们是独立处理的。在这里，我们研究了在四个不同的试验区将两个DEM合并成一个单一的复合DEM可以获得什么。在分析一个试验区的相对差异和与绝对参考值的偏差的基础上，提出了一种将两个DEM优化组合的算法。然后，我们将复合DEM与单独的DEM以及德国南部一个试验区的大量精确GPS剖面进行了比较。我们发现，在我们的试验区，复合DEM中的缺失值面积显著减少。即使与更完整的C波段DEM相比，空像素数也可以减少22%到53%。此外，由于干涉相位展开中的误差而导致的离群值通常可以在合并中被识别和去除。C波段和X波段DEM与GPS基准的偏差非常相似，完全符合全球数据集的精度要求。合成DEM与参考值之差的标准差比原始值低约14%。根据对完整性和精度的要求，合并两个SRTM高程数据集可能会比原始DEM中的任何一个都有重要的改进。
Two different digital elevation models (DEM) were derived during the 2000 Shuttle Radar Topography Mission from C- and X-band interferometric radar data. While these two DEMs share several of their properties, they were processed independently. Here, we investigate what can be gained by merging the two DEMs into a single composite DEM for four different test areas. Based on an analysis of the relative differences and the deviations from an absolute reference in one test area, we propose an algorithm for combining the two DEMs optimally. We then compare the composite DEM with both individual DEMs and with a reference of a large number of precise GPS profiles in one test area in southern Germany. We find that in our test areas, the area of missing values is reduced significantly in the composite DEM. Even compared with the more complete C-band DEM, the number of void pixels can be reduced by 22 percent to 53 percent. Also, outlier values resulting from errors in the interferometric phase unwrapping can often be identified and removed in the merging. The deviations of both C- and X-band DEMs from the GPS reference are very similar and well within the accuracy specifications of the global data set. The standard deviation of the difference between the composite DEM and the reference is about 14 percent below that of the original values. Depending on the requirements for completeness and accuracy, merging the two SRTM elevation data sets may provide an important improvement above either of the original DEMs.