The application of a long-range laser scanner for monitoring volcanic activity on Mount Etna

There is a requirement for rapid remote monitoring of ground deformation of volcanoes, especially during eruptions. A long-range reflector-less laser scanning instrument, manufactured by Riegl Laser Measurement Systems, was used on Mount Etna in October 2000, and its potential for monitoring ground surface changes associated with volcanic activity was evaluated. The 3DLM LR1 scanner system can measure distances up to 2 km with an accuracy of ±25 mm in typical conditions. Measurement rates range from 1 point per second at 2 km to 4 points per second at 10 m. The system also records reflective intensity, and this proved useful in distinguishing between different types of volcanic material. Cloud and gas obscured some measurements, but the scanning nature of the instrument, coupled with effective data filtering software, allowed robust digital terrain models to be created.