FOTOGRAMETRÍA DIGITAL TERRESTRE PARA LA DOCUMENTACIÓN PATRIMONIAL: EL CASO DEL MUSEO DE CIENCIAS NATURALES

Abstract

Precision technical documentation of heritage buildings is critical in the face of advanced deterioration processes. This article evaluates the effectiveness of terrestrial digital photogrammetry as a non-invasive survey tool applied to the Pabellón Centenario of the Museo de Ciencias Naturales at the Universidad Nacional de Salta (UNSa, Argentina). Using a Nikon D5500 camera and Agisoft Metashape Professional software, two operational scenarios were analysed with the same sensor base (24.2 MP APS-C): Scenario A, with optimal stand-off conditions on the west façade (24 mm lens, 84 images, capture GSD 1.12 mm/pix), and Scenario B, with physical restrictions due to vegetation and occlusions on the south façade (35 mm lens, 290 images, capture GSD 1.11 mm/pix). Both scenarios achieved a virtually identical capture GSD, while Scenario B produced an orthomosaic 1.7 times more resolved (2.23 vs. 3.77 mm/pix) and a 1.7 times denser point cloud, at a computational cost 5.3 times higher in processing time. Metric precision was validated using a laser rangefinder and printed markers, yielding relative errors below 0.65% in all measured distance pairs. Results demonstrate that terrestrial photogrammetry produces dense point clouds and high-resolution orthophotographs suitable for the diagnosis of constructive pathologies. The presence of obstacles nonetheless underscores the need to integrate hybrid methodologies incorporating aerial UAV systems for comprehensive heritage building documentation.