Multi-Sensor Geomatic Techniques for the 3D Documentation and Virtual Repositioning of Elements of the Church of S. Miguel (Jaén, Spain)

Abstract

This study describes the methodology and main results obtained after applying several geomatic techniques, based on the fusion of data acquired by several sensors, to document the recovery works carried out in an abandoned church. A century ago, the façade was moved to a museum to ensure its preservation. In addition to documentary purposes, a secondary goal is the virtual repositioning of a model of this element on that of the church. The method takes advantage of the potential of each technique, considering the acquisition of geometry based mainly on laser scanning techniques and radiometry on photogrammetry. The results include 3D models and orthoimages, which are used to perform a stratigraphic study. The 3D model of the façade has been repositioned in the general one, considering common geometries previously fitted in both models and repeating part of the photogrammetric process, using masks to define the image areas related to the church and the façade. Therefore, we obtained a 3D model with the façade included in it. This procedure has demonstrated its feasibility despite the existence of different environmental conditions in both areas. Using these results, we have also developed a BIM to allow for the management of future restoration works.