Generation of 3D virtual geographic environment based on laser scanning data | |
| Author | Du, Jie |
| Call Number | AIT Diss no.NR-02-02 |
| Subject(s) | Geography--Mathematical models Scanning systems |
| Note | A dissertation submitted in partial fulfillment of the requirements for the Degree of Doctor of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation; no NR-02-02 |
| Abstract | Over the past few years, many kinds of raster and vector based models for describing, modeling, and visualizing three-dimensional (3D) spatial data on a large scale, have been developed. With the development of laser technology and sensor techniques, several types of airborne laser scanners are available for the acquisition of high accuracy 3D spatial data in closed real or very fast time. The main application of laser scanning systems concerns large-scale and precise topographic Digital Terrain Models (DEMs) and Digital Surface Models (DSM), especially in areas that are difficult for conventional photogrammetry. Hence, Laser technology has been brought into photogrammetry and cartography fields as a tool for mapping. The main research problems are: automatically interpreting range images for extracting geo-spatial features and the reconstrnction of geo-objects. The objective of this research is to develop algorithms and methods for the modeling and visualization of 3D spatial data on a large scale to reconstruct 3D spatial objects by using the laser range data, based on using laser-scanning data. A set of algorithms was developed for processing airborne laser range data. Those algorithms mainly included: Triangulated Irregular Network (TIN) based range image interpolation; Mathematical Morphology (MM) based range image filtering, features extraction and range image segmentation, feature generalization and optimization; 3D objects reconstruction and modeling; Computer Graphic (CG) based visualization and animation of virtual environment. To reconstruct large-scale 3D spatial objects by using the laser range data, existing maps and images, laser range images can be considered as a kind of high-resolution DTMs or DSMs. The reconstruction of 3D objects from laser range images can be simply thought as the 3D raster-vector conversions from a noise DTM to parametric CAD fo1matted 3D vector data. Due to the limited resolutions and noise, the existing low level processing methods for reconstruction of 3D objects from laser range images generally cannot fit to real application needs. Regional planning maps serve as a set of well-organized high-level data sources, which can be interpreted and generalized for subsequent 3D object reconstruction and recognition. In order to map the details of objects, fundamental surveying is brought to data-collection processes in terms of data acquisition. After storage the laser range data in the proper format, data should be filtered in order to reduce any enor accumulated during the collecting processes. Scene Modeling is the next step to create 3D model, after pass filtering. Triangulation, segmentation and extraction are also involved in the Scene Modeling process in terms of mathematical algorithms. Then all data should be combined based on combination modeling established for this purpose. The combination process, consist of algorithms to be used for merging different kinds of data to be applied to this process. GIS attribute data, aerial photograph and existing maps combine with laser range data. The results of this work can be shown in a generated 3D visual geographic environment. This research can be applied to several types of works. |
| Year | 2002 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation; no. NR-02-02 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Development and Sustainability (DDS) |
| Academic Program/FoS | Natural Resources Management (NRM) |
| Chairperson(s) | Apisit Eiumnoh; |
| Examination Committee(s) | Xiaoyong, Chen; Kusanagi, Michiro; Shrestha, R. P.;Peng, Gong; |
| Scholarship Donor(s) | -; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2002 |