Assessment and validation in time domain of a Robust Satellite Technique (RSTASH) for ash cloud detection

The Robust Satellite Technique (RST) approach is a general scheme of satellite data analysis used to study several natural and environmental hazards. In this paper, the results of a long-term time domain analysis, performed on its RSTASH configuration, specifically tailored to detect and track volcanic ash clouds, are presented. One year of satellite sub-scenes provided by the Advanced Very High Resolution Radiometer (AVHRR), covering an area of about 90 000 km2 around Mt Etna volcano (Italy), was analysed in order to assess RSTASH performances in periods of ash emissions, as well as during unperturbed conditions (i.e. no ash events). The results and limits of such an approach are discussed, together with possible further improvements achievable by its implementation to different satellite sensor data, e.g. EOS-MODIS and MSG-SEVIRI.