On the use of terrestrial laser scanner for deformation analysis of the Talaga Bodas Crater West Java (Indonesia)

Abstract

Talaga Bodas Volcano, located near the border of Garut and Tasikmalaya regencies, West Java, Indonesia, is an active stratovolcano whose apparent shape is mainly dominated by the steep-side-cone type. Hence, monitoring Talaga Bodas Volcano to mitigate its potential hazard is extremely necessary. In this research, potential hazards are studied by observing and monitoring the deformation of the Talaga Bodas Crater using the geodetic Terrestrial Laser Scanner (TLS) tool. TLS is a relatively new positioning method in geodesy. TLS is able to obtain the position of the object points (point clouds) in a huge amount and high precision in a relatively short time. This research aims at identifying the deformation and also rock textures and structure around the Crater of Talaga Bodas. The methodology used in this research is by obtaining the scanning data using TLS in 2012 and 2015 and GPS measurements to obtain the coordinates of the reference points. The data processing methods consist of several steps, namely target to target registration, filtering, georeference, and analysis of the registered point clouds. These steps were done using the cyclone 8 software. Registered point clouds show the 3 dimension of the crater. It was found that the average values for the down-lift and up-lift deformation around the crater are about -6.4 cm and 5.1 cm, respectively. Reflected point clouds show the differences of the intensity color of the surface around the crater. This result indicates the differences of the rocks texture and structure around the crater.