|
|
Enhancement of DTM in Sandstone Landscapes Using Precise Registration of Airborne Laserscanning Data
Holman, Lukáš ; Lysák, Jakub (advisor) ; Dušánek, Petr (referee)
DTM Improvement in Sandstone Cliffs Relief using precise Co-registration of Airborne Laser Scanning Data Abstract The topic of this thesis is to design innovation of methodology improvement of digital terrain models from airborne laser scanning data in sandstone rocks rugged relief. Theoretical part of this thesis presents the Project GeNeSiS and New Elevation Model Project of the Czech Republic Territory, in which the test datasets were acquired. Simultaneously this section describes in detail methods of co-registrations datasets from strip adjustment to 3D least squares matching method, which have been published until now. In practical part of the work the Pravčická brána model region is introduced firstly. The focus of this section lays on description of new methodology for co-registration and classification of point clouds using spatial query. Co-registration of point clouds, respective detection transform parameters in this thesis is solved by introducing ground control areas. For each such region displacement and rotations in each axis are detected which subsequently determines the global transformation key. Innovation of the thesis lies in the fact that for DTM improvement there is sufficient only one point cloud. The second (and possibly others) point cloud is classified by presented algorithm...
|
|
|
Classification of Airborne Laser Scanning Data in Sandstone Landscapes
Tomková, Michaela ; Lysák, Jakub (advisor) ; Potůčková, Markéta (referee)
Classification of Airborne Laser Scanning Data in Sandstone Landscapes Abstract This work is concerned with the classification of airborne laser scanning data in sandstone landscapes called "rock cities". Standard filters do not work reliably in such a rugged terrain covered with dense vegetation and in the results the rock formations are smoothed or even removed from the terrain. The method of classification suggested in this work is based on the procedure used in manual filtration. When exploring a sufficiently dense point cloud in 3D, one is able to distinguish rock formations from trees even though their shapes are similar. In contrast to trees, rock pillars are modeled only by points reflected off the surface and therefore they make concave elevations in the ground. Because of penetration of trees, there are points reflected off a treetop, branches, leaves and also ground under the tree. The proposed method segments a point cloud according to local minima in approximated surface and classifies these objects into classes rock, tree, and mix by inner point distribution. Objects in classes tree and mix are then filtered by lasground function from LAStools. The method was tested with merged point cloud consisted of data from the standard airborne laser scanning of the Czech Republic and experimental...
|
|
|
Sandstone Landscapes in GIS
Tomková, Michaela ; Lysák, Jakub (advisor) ; Holešinský, Oldřich (referee)
Sandstone Landscapes in GIS Abstract This work is concerned with the representation of sandstone rock formations in digital topographic database. It is based on raster datasets derived from digital relief models created from airborne laser scanning (ALS) data. Objects representing rock faces and their edges, rock pillars and peaks, rugged plateaus, cracks and scattered rocks were created in software ArcGIS for Desktop using scripts in Python. Some of these objects also contain attributes like classification of the object and elevation. Testing was performed on ALS data with various density of point cloud in geomorphologically different sandstone landscapes in Bohemia. Field research was conducted in one of the places of interest to verify the reliability of the digital relief model. Key words: rock formations, sandstone landscapes, digital topographic database, GIS
|
|
|
Enhancement of DTM in Sandstone Landscapes Using Precise Registration of Airborne Laserscanning Data
Holman, Lukáš ; Lysák, Jakub (advisor) ; Dušánek, Petr (referee)
DTM Improvement in Sandstone Cliffs Relief using precise Co-registration of Airborne Laser Scanning Data Abstract The topic of this thesis is to design innovation of methodology improvement of digital terrain models from airborne laser scanning data in sandstone rocks rugged relief. Theoretical part of this thesis presents the Project GeNeSiS and New Elevation Model Project of the Czech Republic Territory, in which the test datasets were acquired. Simultaneously this section describes in detail methods of co-registrations datasets from strip adjustment to 3D least squares matching method, which have been published until now. In practical part of the work the Pravčická brána model region is introduced firstly. The focus of this section lays on description of new methodology for co-registration and classification of point clouds using spatial query. Co-registration of point clouds, respective detection transform parameters in this thesis is solved by introducing ground control areas. For each such region displacement and rotations in each axis are detected which subsequently determines the global transformation key. Innovation of the thesis lies in the fact that for DTM improvement there is sufficient only one point cloud. The second (and possibly others) point cloud is classified by presented algorithm...
|
guest ::
