Cultural heritage 3D modelling and visualisation within an augmented reality environment, based on geographic information technologies and mobile platforms

This article applies Geographic Information Technologies (GIT) to the field of Cultural Heritage (CH), aiming to analyse patrimonial valuation through Digital Representations (DR). It seeks to briefly introduce the importance of DR through the concepts of the individual’s spatial cognition (mental) and physical (external) perceptions. It approaches the main topics of 3D data acquisition, modelling and visualisation, as well as cultural heritage applications, and presents 3D and Augmented Reality (AR) trials, together with their main results and discussion. The methodology consists of exploratory data acquisition using terrestrial and Unmanned Aerial Vehicles (UAV), 3D modelling procedures, and the integration between 3D-Geographical Information Systems (GIS) and AR environments (mobile platforms) applied to patrimonial systems and elements in urban areas. The results consist of several Trials and products of 3D acquisition and modelling processes to be visualised in an AR environment. These allow for adjusting the core solutions for further mobile application development. Taking the ancient Lisbon (Aqueduct) water supply system (classified as a national monument) as a case study, the fact that most of it is imperceptible, owing to the large extent of the undergrown galleries, enables the onsite visualisation of the relation between the system and the city elements within a mixed reality environment. The methods used aimed to strengthen 'the idea of the potential application of this technology for heritage valuation, associating the use of geographic information to fields commonly related to a strong visual perception of space, providing essential data not only for occasional users (public), but also for specialised technicians, opinion/decision makers, promoters and other stakeholders.