A Study of the Accuracy of a 3D Indoor Camera for Industrial Archaeology Applications

The paper aims to study the geometrical quality and opportunities of the state-of-the-art 3D camera Matterport Pro and examine its potential for industrial archaeology applications. The presented study consisted of two steps. In the first step, the geometrical quality of the camera-generated point cloud was investigated on the calibration test field. The geometrical quality was checked in two ways: (1) with distance comparison between reference targets and (2) with point cloud comparison. The coordinates of the reference targets were determined using a high-precision total station, while the FARO Scanner generated the reference point cloud. The study established that Matterport Pro has a scale systematic error that must be accounted for in 3D modeling and the inventory of archaeological objects. In the second step, the geometrical quality of the camera was checked for the actual archaeological object. As such an object, the historical copper-shaft Quincy Mine in Michigan State Upper Peninsula was considered. The specific subject of the study was one of the largest hoist engines in the world. The Matterport Pro camera scanned the indoor environment of the hoist engine house. The accuracy of the 3D model of the hoist engine was checked using additional linear measurements on-site. It was found that the accuracy of 1% showed that the camera specification can be improved through calibration. As an output of the second step, the accurately refined 3D model of the hoist engine's interior was built. That model was embedded into a 3D model of the hoist engine's house for usage in virtual tours of the Quincy Mine Museum. Finally, a virtual tour was created of the Quincy Mine house with exterior and interior models referenced to the geographical frame.