Investigating the Accuracy of a 360° Camera for 3D Modeling in Confined Spaces: 360° Panorama vs 25-Rig Compared to TLS

Abstract. This study investigates photogrammetric solutions for surveying confined underground environments using a small and affordable 360° camera, applied in Tomb 4 at the UNESCO World Heritage Site, Tombs of the Kings in Paphos, Cyprus. Conducted within the framework of the ENGINEER project, this study evaluates the performance of a low-cost 360° 25-lens camera by comparing it to a terrestrial laser scanner (TLS) system used as a reference. The primary objective is to assess the suitability of the 360° camera for 3D documentation in restricted spaces, and to explore its potential application in conservation and restoration efforts at archaeological sites. Two different approaches were tested: using the camera images as 360° panoramic photos or as 25-photos rigid rig setup. The study analyses the accuracy of these methods by generating Point Clouds (PCs) and comparing them to the TLS reference dataset using metrics such as cloud-to-cloud distance, surface roughness, and PC density. In addition, a visual assessment was conducted.