Assessment of the Robust Satellite Technique (RST) for volcanic ash plume identification and tracking

Volcanic clouds pose a serious threat for both aircrafts and passengers because of ash, which may cause serious damages to the flight control systems and to jet engines. Starting from 2007, an automatic satellite monitoring system has been implemented at IMAA (Institute of Methodologies of Environmental Analysis) to identify and track volcanic ash plumes using NOAA-AVHRR data. This system is capable of providing reliable information about possible volcanic ash plumes over a region of interest (ROI) within a few minute after the sensing time, thanks to the implementation of a robust multi-temporal approach of satellite data analysis named RST (Robust Satellite Technique). This approach has already shown a high potential in successfully identifying and tracking volcanic ash clouds compared to traditional techniques, both in its standard (i.e. two-channel) and advanced (i.e. three-channel) configuration. In this paper, RST performances for ash plume detection and monitoring will be further assessed, showing some recent results obtained during December 2006 and analyzing a time series of satellite observations carried out over Mount Etna area for different months in different observational conditions. In order to validate and assess RST performances, a long-term time domain analysis is in progress, also investigating periods mainly characterised by quiescent phases (i.e. with no ash emission episodes). Preliminary results of such a statistical analysis will be presented and the possible contribution of this satellite monitoring system in supporting management of strong eruptive crisis will also be discussed.