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Casacchia, R.
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- PublicationRestrictedSpectral properties of volcanic materials from hyperspectral field and satellite data compared with LiDAR data at Mt. Etna(2009-04)
; ; ; ; ; ; ; ; ; ;Spinetti, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia ;Casacchia, R.; CNR, Dipartimento Terra & Ambiente, Rome, Italy ;Colini, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Behncke, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Salvatori, R.; CNR, Ist Inquinamento Atmosfer, Rome, Italy ;Buongiorno, M. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Pareschi, M. T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; ; ; ; ; ; ; ; Spectral properties of volcanic materials in the optical region (350–2500 nm) of the electromagnetic spectrum are analyzed. The goal is to characterize air-fall deposits, recent lava flows, and old lava flows based on their spectral reflectance properties and on the textural characteristics (grain size) of pyroclastic deposits at an active basaltic volcano. Data were acquired during a spectroradiometric field survey at Mt. Etna (Italy) in summer 2003 and combined with hyperspectral satellite (Hyperion) and airborne LiDAR (Light Detection and Ranging) data. In addition, air-fall deposits produced by the highly explosive 2002–2003 eruption have been sampled and spectrally characterized at different distances from the new vents. The spectral analysis shows that air-fall deposits are characterized by low reflectance values besides variations in grain size. This distinguishes them from other surface materials. Old lava flows show highest reflectance values due to weathering and vegetation cover. The spectral data set derived from the field survey has been compared to corrected satellite hyperspectral data in order to investigate the Hyperion capabilities to differentiate the surface cover using the reflectance properties. This has allowed us to identify the 2002–2003 air-fall deposits in a thematic image just few months after their emplacement. Moreover, the observed differences in the field spectra of volcanic surfaces have been compared with differences in the signal intensity detected by airborne LiDAR survey showing the possibility to include information on the texture of volcanic surfaces at Mt. Etna. The approach presented here may be particularly useful for remote and inaccessible volcanic areas and also represents a potentially powerful tool for the exploration of extraterrestrial volcanic surfaces.491 45 - PublicationOpen AccessRiflettanza di superfici vulcaniche:la campagna 2003 sul Monte Etna(2006-09-01)
; ; ; ; ; ; ; ; ; ; ;Casacchia, R.; CNR - Istituto sull’Inquinamento Atmosferico, 00016 Monterotondo Stazione, Roma. ;Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Spinetti, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Colini, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Behncke, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Buongiorno, M. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;DeSantis, V.; CNR - Istituto sull’Inquinamento Atmosferico, 00016 Monterotondo Stazione, Roma. ;Grignetti, A.; CNR - Istituto sull’Inquinamento Atmosferico, 00016 Monterotondo Stazione, Roma. ;Salvatori, R.; CNR - Istituto sull’Inquinamento Atmosferico, 00016 Monterotondo Stazione, Roma.; ; ; ; ; ; ; ; ; The results obtained in Mt. Etna spectroradiometric field survey of June 2003 are presented and discussed. The goal of the survey was the analysis of the reflectance properties of the young pyroclastic deposits produced after the effusive activity of 2002-2003 and of the older lava flows. To achieve this goal, a template was created in order to organize the field data collected in a number of selected sites characterised by different surface materials. The results show that reflectance of pyroclastic flows is always very low and constant, besides grain size and composition of the flow. Pahoehoe units show higher reflectance values, even though the spectral characterisation of the older lava flows must take into account weathering products and vegetation coverage.413 470