Storing Massive TINs in a DBMS: A comparison and a prototype implementation of the multistar approach

Solutions have been introduced to handle massive point clouds in Database Management Systems (DBMS), namely by Oracle in 2011 and postgreSQL in 2013. Many common operations on these massive point clouds require knowledge about the original surface in order to analyse them. A possible method to recreate a representation of the original surface is...

Automatic repair of geometrically invalid 3D City Building models using a voxel-based repair method

In recent years, the concept of 3D city models has been gaining in importance as more 3D geometry of urban areas is becoming available. Although 3D City models offer a structured way of storing geometry, in practice a significant amount of geometry is not considered valid. This hinders the further analyzing or processing of these models. Since...

Automatic generation of CityGML LoD3 building models from IFC models

CityGML is a standardized data format used to store the semantic information and geometries of buildings and other object classes of 3D city models. The Level of Detail of current state of the art city models (LoD2) is not sufficient for accurate environmental simulations like noise, the solar potential of windows and other types of analyses. An...

A Voronoi- and surface-based approach for the automatic generation of depth-contours for hydrographic charts

Depth-contours are an essential part of any hydrographic chart—a map of a waterbody intended for safe ship navigation. Traditionally these were manually drawn by skilled hydrographers from a limited set of surveyed depth measurements. Nowadays this process of map making is shifted towards the digital domain, not in the last place because of the...

Knowledge-based optimisation of three-dimensional city models for car navigation devices

Three-dimensional maps are deemed better for navigation purposes as they offer a larger number and more realistic navigation cues than two-dimensional maps. Improvements in two key technologies have opened the doors towards utilization of 3D maps for car navigation devices. Advances in data acquisition technologies and data processing methods...

Quality assessment and object matching of OpenStreetMap in combination with the Dutch topographic map TOP10NL

The possibility of an automatic object matching process in combination with a VGI (Volunteered Geographical Information) type of map has been explored in this research. TOP10NL, the topographic map of the Netherlands and OpenStreetMap (OSM), the VGI type of map have been chosen for this purpose. The object matching process in this research...

Footprint decomposition combined with point cloud segmentation for producing valid 3D models

For the creation of three-dimensional (3D) city models, extrusion of building footprints is widely applied. Extrusion results in block shaped buildings. The main problem with these 3D models is that they do not represent height differences within a building. This thesis presents a method to improve building footprints by subdivision into parts...

Validation and Automatic Repair of Planar Partitions using a Constrained Triangulation

Planar partitions (subdivisions of the plane into polygonal areas) constitute one of the most important data representations in GIS. They are used to model concepts as varied as land use, administrative units, natural features and cadastral parcels, among many others. However, since polygons are often stored separately, different errors and...

Automatic segmentation and classification of movement trajectories for transportation modes

The knowledge of the transportation mode used in a movement trajectory (derived in form of timestamped positions) is critical for applications such as travel behaviour studies. This thesis presents a method for segmenting movement data into single-mode segments and their classification with respect to the used transportation mode. The method...

Using the discrete 3D Voronoi diagram for the modelling of 3D continuous information in geosciences

In this thesis the use of the discrete 3D Voronoi diagram in modelling continuous fields in geosciences will be assessed. The Voronoi diagram is a structure that divides a certain space into cells, called Voronoi cells. These cells are created so that every location within each cell is closest to the corresponding data point, or seed, of that...