Selogriyo Temple Deformation Mapping in Three Dimensions (3D) Multitemporal Using Terrestrial Laser Scanner (TLS) Technology

Abstract Historical buildings such as the Selogriyo Temple are an important part of Indonesia’s cultural heritage. This temple is vulnerable to risks such as environmental changes, seismic shocks, changes in load, and natural aging, which can cause structural deformation. This research aims to analyze the deformation of Selogriyo Temple through multitemporal 3D modeling and highlights the importance of better mapping methods to monitor the deformation of historical buildings. Mapping was carried out using Terrestrial Laser Scanner (TLS) technology to produce 3D deformation analysis using the surface-to-surface method, which was tied to coordinates from GNSS measurements using Total Station Reflectorless (X and Y) and waterpass/leveling (Z). This research also includes the development of more accurate and efficient measurement techniques and the promotion of modern TLS technology. The results include the 3D model of Selogriyo Temple for the second epoch and the surface-to-surface method deformation model, showing measurement accuracy with a distance similarity value of 99.70% compared to the Total Station tool and 99.73% compared to the steel meter. The 3D model has RMSE coordinate X of 0.012 m, Y of 0.0099 m, and Z of 0.005 m. Multitemporal deformation analysis was tested using the T-test at the 95% confidence level, showing an average shift of 0.000332 with a standard deviation of 0.0097. The results of the one-sample T-test show a t-statistic of 0.1869, lower than the critical value of t at the significance level α = 0.05, which indicates the statistical insignificance of the shift. Based on the second epoch 3D modeling, the slope of Selogriyo Temple is still relatively light with a value of 0-1°.