Bart De Wit

Accurate and Cost-Efficient 3D Modelling Using Motorized Hexacopter, Helium Balloons and Photo Modelling: A Case Study

The destructive nature of archaeological excavations and the spatial character of archaeological finds make 3D models valuable contributions to the documentation of archaeological information. Laser scanning allows highly accurate 3D reconstructions, but involves considerable costs and expert knowledge. Therefore, photo modelling could be considered as a useful alternative. In this paper, we will demonstrate on the one hand the cost-efficiency and the consequent time-efficiency of the technique and on the other hand its (sub-decimeter) accuracy. Furthermore, the possibilities and advantages of motorized unmanned aerial vehicles (UAV) and helium balloons as airborne platform for image acquisition are shown. For this purpose, a case study is performed at the Mayan archaeological site of Edzna (Mexico). Using the Structure from Motion (SfM) and Multi-View Stereo (MVS) algorithm, terrestrial and aerial photographic recordings are processed into the final 3D models. For the quality assessment the photographic recordings are supplemented with topographic measurements.

Design and use of web lectures to enhance GIS teaching and learning strategies: the students’ opinions

The goal of this research is to design, use and evaluate a set of web lectures, specifically tailored to the needs of students in higher education who follow geographic information system -related courses. Since education in geographic information system includes theoretical concepts and practical experience, both of these teaching strategies will be implemented in the web lectures. The user-centered design approach is used in the design process to increase the acceptance of the web lectures and the motivation to use them: perceived usefulness and ease of use. The results show that the students appreciate the initial set of web lectures, but that they need to be motivated more to use them (especially when theoretical topics are covered). Students still value the “traditional” face-to-face lectures and see the web lectures as an ideal complement.

User-Centered Design of a Collaborative, Object Oriented Historical GI-Platform

The project STREAM (Spatio-Temporal Research Infrastructure for Early Modern Flanders and Brabant) aims to create a research infrastructure that will allow spatio-temporal analyses in order to improve our understanding of the demographic, social and economic changes that occurred in Flanders and Brabant (Belgium) between 1550 and 1800. The Carte de Cabinet of count Joseph de Ferraris (1771–1778) offers information on various subjects for that time period and is considered one of the most important products of Belgian cartographic history. Hence this historical map was used as the main source document to develop a vectorial geographical database that constitutes an important step towards the creation of a research infrastructure. To build this geographical database a retrogressive method was used in order to interpret the historical map and its related data in an absolute geographical reference system, which the Carte de Cabinet lacks. Since STREAM results from a collaboration between researchers from different disciplines a specific user-oriented editing platform was developed to support the different actors. This platform allows the digitisation of the historical road network in a geographic reference system based on the current road network by means of a slider, a shift tool and an editing tool. Initial analyses have confirmed the strong geometric distortions of the Carte de Cabinet but also the multiple possibilities for spatio(-temporal) research when combining the information of the Carte de Cabinet with cartographic analyses of other cartographic documents.