OPTECHTM ILRIS-3D TERRESTRIAL LASER SCANNER: SHORT USER GUIDE

Abstract

The OptecTM ILRIS-3D Terrestrial Laser Scanner (TLS) has been recently acquired by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) Sezione di Bolgna in the context of a TTC program for volcanoes monitoring (TTC 1.3 Controllo Geodetico delle Aree Vulcaniche Attive) supported by the Dipartimento di Protezione Civile. Several experiments were performed by INGV since 2004 to study the level of precision for surface modelling by means of laser scanner long range instruments, in order to detect the best suitable standard for rapid and simple acquisition in volcanic area (Pesci et al., 2007). In particular, during the MESIMEX experiment (October 2006), a national exercitation organized by the Dipartimento di Protezione Civile (DPC) exploited to simulate a volcanic eruption in Naples, the second TLS survey of the whole Vesuvius crater was executed and a large mass variations were estimated revealing the collapse of a portion of the crater. The alignment and comparison of point clouds (2006–2005) show high variations over a large portion of the NE slope and a volume variation of about 6850 m3 was computed. The analysis was performed in almost real time by means of direct comparisons between scans, indicating the laser scanning as one of the most reliable technique for fast monitoring in crisis time (Pesci et al. 2008a). The main characteristics recommended for surveying in volcanic areas were the laser device eyes safety, the achievable very long range (> 1 km), the precision of measurements and final accuracy in data modelling, the acquisition velocity, the instrument portability in terms of weight and size and the ability to manage scanner by means of PC pocket. The ILRIS-3D scanner was chosen based on the previously described recommended points. The simple operation needed for scan execution and the possibility to plan and realize a complete survey by means of only two operators confirmed ILRIS-3D as the best choice for volcanic applications. This technical report is a simple and effective user guide for laser scanner management providing all the necessary instruction from instrument settings, remote connection, data storage, downloading and preprocessing. Authors proposal is to make operators independent enough to scan and carry out survey in interested areas also without a specific experiences in LIDAR (Light Detection And Ranging) monitoring.