A Study in Preserving Cultural Heritage Using Portable Laser Devices Embedded in Mobile Phones

Abstract

There is a need for more documentation and quantitative data on architectural and cultural objects, especially considering the deteriorating condition of certain historical assets and the required treatments for them. In this circumstance, it is crucial to have metric documentation of the history being investigated in order to comprehensively comprehend the asset and aid engineers and architects in the restoration process. 3D data acquisition technologies, such as the photogrammetric approach, are frequently associated with high costs. Alternatively, it may necessitate a significant investment of both time and effort, prompting users to explore cost-effective solutions that nevertheless allow them to achieve their desired levels of precision. Recently, geomatic equipment and processes have been developed to optimize efficiency and cost-effectiveness in surveying cultural assets. Apple has incorporated a LiDAR sensor into its products, enabling the creation of a three-dimensional representation of objects or locations. This project aims to assess the precision and practicality of this sensor in generating three-dimensional depictions of cultural artifacts. The study explores the capacity of iPhone lidar (IPL) to aid in the conservation of cultural heritage, examines potential barriers and difficulties that may develop, and evaluates its effectiveness in certain areas. To assess the accuracy of each technique, a scan was performed on the case study utilizing Close Range Photogrammetric (CRP) & iPhone 13 pro max, with confirmed artificial targets monitored by Total Station (TS). The results indicated that the root mean square error (RMSE) for IPL was 8mm, whereas for TLS it was 3mm. The lidar sensor has rapid scanning capabilities at a relatively cheap expense while maintaining an acceptable level of precision. However, it should not be regarded as a replacement for TLS, as the latter is an indispensable instrument for collecting data over wider distances. The causes for this are the sensor's precision, its ability to cover vertical space, and its restricted range, which is capped at a maximum of 5 meters. The sensor's specification is expected to undergo additional improvements and advancements, despite these limitations. A crucial tool for collecting data over extensive regions.