Remote sensing of volcanic terrains by terrestrial laser scanner: preliminary reflectance and RGB implications for studying Vesuvius crater (Italy)

This article focuses on the use of terrestrial laser scanner (TLS) in the characterization of volcanic environments. A TLS survey of the Vesuvius crater (Somma-Vesuvius volcano, Italy) allows the definition of an accurate and georeferenced digital model of different sectors of the crater. In each sector, the intensity is computed for each point as the ratio between the emitted amplitude and the received one, normalized to the maximum signal. Moreover, the RGB colors of the observed surfaces can be captured by means of a calibrated camera mounted on the TLS instrument. In this way, a multi-band information is given, since a long range TLS operates in the near infrared band. The reflectance and RGB data are compared to verify their complementarities for model analysis and inspection. The collected data allowed the recognition of different volcanic deposits and stratigraphic features. In addition, our results shed light on the spatial extension of landslides and on the dimensions of rock fall/flow deposits affecting the inner walls of the crater.