Laser Scanning Technology for the Hypogean Survey: the case of Santa Barbara Karst System (Sardinia, Italy)
Erminio Paolo Canevese, Paolo Forti, Angelo Naseddu, Luciano Ottelli, Roberta Tedeschi - (40/1,2011)
The morphological knowledge of the territory, both in its surface and subterranean aspects, is the main premise to all decision-making procedures as well as all planning and management activities. Knowledge takes shape into reliable precise and complete thematic cartography and databases, which are necessary for anybody dealing with underground contexts: speleologists, scientists, public administrations, managing authorities etc. Surveys in caves are normally carried out with traditional techniques and instruments, which are essential for a first representation but not enough for a pragmatic effective topographic approach. Laser scanning technique can be an alternative to the traditional systems. Laser scanning quickly acquires the shape of cavities as “point clouds” (x, y, z coordinates and colour values) and produces a high precision database of the surveyed object. Laser scanning technology is therefore a feasible way to document caves in a precise exhaustive way, limiting risks relating to lack and/or inadequacy of data. The present paper explains the laser scanning survey carried out in San Giovanni mine near Iglesias (Sardinia, Italy), particularly in Santa Barbara and Santa Barbara 2 caves, the data post-processing and three-dimensional modelling of “point clouds” (operations performed with a dedicated software), and the use of the obtained digital model. Moreover, the paper describes the advantages of laser scanning for the hypogean survey in comparison to traditional methods and the future potentialities of a broad application of laser scanning instruments in caves.