This digital elevation model (DEM) describes the topography of the active floodplain of the middle reaches of River Elbe between the Czech-German border near Schmilka and the weir in Geesthacht with 1 m spatial resolution in coordinate reference system "ETRS 1989 UTM Zone 33 N" and 0.01 m resolution in the German height reference system "Deutsches Haupthöhennetz 1992 (DHHN92)". The dataset was generated through aerial laser scanning (ALS) for terrestrial parts of the floodplain between April 2003 and December 2006 and echo sounding for aquatic parts of the central water course by the local waterway and navigation authorities (WSV) throughout the year 2006. Parts not covered by any of the two data collection methods were filled through linear interpolation. A comparison between DEM and 7476 height reference points confirmed a high accuracy with a mean deviation of elevations of ± 5 cm. Depending on the data source 95% of all checked points show a vertical deviation of less than 15 cm to 50 cm. A small section of the model was updated later to incorporate the dike relocation area Lenzen which became connected to the floodplain in 2011 so that the dataset describes the state of 2011. Since the dataset has a large volume it was split into 49 tiles.
This digital elevation model (DEM) describes the topography of the active floodplain of the freeflowing parts of River Rhine between the weir Iffezheim and the German-Dutch border near Kleve with 1 m spatial resolution in coordinate reference system "ETRS 1989 UTM Zone 32 N" and 0.01 m resolution in the German height reference system "Deutsches Haupthöhennetz 1992 (DHHN92)". The dataset was generated in four parts through aerial laser scanning (ALS) for terrestrial parts of the floodplain and echo sounding for aquatic parts of the central water course by the local waterway and navigation authorities (WSV) between 2003 and 2010. Parts not covered by any of the two data collection methods were filled through linear interpolation. A comparison between DEM and reference points confirmed a high accuracy with a mean deviation of elevations of ± 5 cm. Depending on the data source 95% of all checked points show a vertical deviation of less than 15 cm to 50 cm. Since the dataset has a large volume it was split into 40 tiles.
Das Projekt "Verbesserte Änderungsdetektion durch integrierte 3-D Information und Fernerkundungsdaten" wird vom Umweltbundesamt gefördert und von Universität Osnabrück, Institut für Geoinformatik und Fernerkundung (IGF) durchgeführt. Change detection is a very important challenge. Various change detection methods are documented in the literature but most of them focus on two-dimensional data which limit their applicability. Therefore, in this project we focus on the development of three-dimensional change detection methods considering three different scenarios. First, we assume that there is no three-dimensional information for both old and new scenes to detect changes. We propose using twodimensional change detection algorithms followed by approximate three-dimension extraction of the changed regions. Here, we will develop novel depth estimation methods based on shadow and shape information. Second, we assume that we have the three-dimensional information (in terms of stereo image pairs) to be available either for the old or the new scene only. To detect changes in three-dimensions, we will construct the digital elevation model (DEM) based on the stereo image matching principle. For the scene having mono image, we will generate the DEM data by shadow and shape information. Using novel three-dimensional change detection methods, we plan to detect changes on these data sets. ...
Das Projekt "Evaluation of the terrain model influence on the Orthorectification of Sentinel-2 satellite images over Austria (S2OrthoQDTM)" wird vom Umweltbundesamt gefördert und von Technische Universität Wien, Department für Geodäsie und Geoinformation (E120) durchgeführt. Aim of the project is to address the concerns on Sentinel-2 geolocation accuracy over the area of Austria. Within Austria's alpine region steep slopes occur. This means that errors in terrain model elevation have a severe effect on lateral displacement, as displacement because of elevation error and because of slope can add up. Errors are expected from SRTM due to radar shadows (InSAR viewing geometry) and other effects. Output of the project is a report, which assesses the geolocation errors expected because of PlanetDEM for the area of Austria. This will be compared to geolocation errors to be expected with a terrain model of superior quality. Errors of the superior model are not determinable, it will act as reference ('ground truth') for PlanetDEM. A second, equally important, output is a suggestion on how to improve the geolocation quality of Sentinel-2 data over Austria. Possibilities on how to improve the product will be discussed. Next to repeating the orthorectification pocress with a better DTM and thus derive a new orthoimage, the grid-shift mechanism5 will be explored, as it might be used for on-the-fly transformation within a GIS. Practical consequences of using the different options will be explored.