Comparison of Different Approaches to Create Architectural Archives

The architectural heritage is continuously at risk due to the threat of multiple catastrophes caused by human and/or natural interference. The importance of architectural archives to help preserving the historical monuments is thus obvious and urgent. Architectural archives can be created by means of terrestrial photogrammetry, using distinct approaches. These approaches relate mainly to the selection of the data acquisition equipment analogue versus digital cameras and among these, metric versus nonmetric cameras – and the data processing and information extraction techniques – stereoscopic versus monoscopic convergent multiimage techniques. The selected technique has implications on the instrument used to process the data, i.e., dedicated (photogrammetric workstation) versus standard computer, which influences accuracy and greatly the costs. In this study we create architectural archives of one Portuguese church with the referred techniques, by using the Photogrammetric Image Station SSK Pro from Intergraph and the software PhotoModeler. The data to create the archives are collected with analogue and digital cameras as well as metric and non-metric cameras. The archives are made up of the photographs/images acquired, the control points, and 3D models in the vector form as well as rendered with rectified images. The church is inserted in its surroundings with the help of 3D urban models. These are created with aerial images and aerial photogrammetry. Multi-media techniques are used to promote the divulgation of the church archives through the Web. The archives are also compared in terms of accuracy. The main conclusion is that architectural archives, of moderate detail, created with the Photomodeler and digital non-metric cameras fulfil the user requirements. ∗ Corresponding author.