Amici, Stefania

This work is an evaluation to which degree geological information can be obtained from modern remote sensing systems like the multispectral ASTER or the hyperspectral Hyperion sensor for a volcanic region like Teide Volcano (Tenerife, Canary Islands). To account for the enhanced information content these sensors provide, hyperspectral analysis methods, incorporating for example Minimum Noise Fraction-Transformation (MNF) for data quality assessment and noise reduction as well as Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) for supervised classification, were applied. Ground Truth reflectance data were obtained with a FieldSpec Pro measurements campaign conducted during later summer of 2007 in the frame of the EC project PREVIEW (http://www.preview-risk.com/).

Extreme environments like active volcanoes exhibit many difficulties in being studied by in situ techniques. For exam-ple, during eruptions, summit areas are very hard to be accessed because of logistics problems and/or volcanic hazards. The use of remote sensing techniques in the last 20 years by satellite or airborne platforms has proven their capabilities in mapping and monitoring the evolution of volcanic activity. This approach has become increasingly important, as much interest is actually focused on understanding precursory signals to volcanic eruptions. In this work we verify the use of cutting-edge technology like unmanned flying system thermally equipped for volcanic applications. We present the results of a flight test performed by INGV in collaboration with the University of Bologna (Aerospace Division) by using a multi-rotor aircraft in a hexacopter configuration. The experiment was realized in radio controlled mode to overcome many regulation problems which, especially in Italy, limit the use of this system in autonomous mode. The overall goal was not only qualitative but also quantitative oriented. The system flew above an Italian mud volcano, named Le Salinelle, located on the lower South West flank of Mt. Etna volcano, which was chosen as representative site, providing not only a discrimination between hot and cold areas, but also the corresponding temperature values. The in-flight measurements have been cross-validated with contemporaneous in-situ acquisition of thermal data and from independent measurements of mud/water temperature.

Thermal remote sensing studies of actively burning wildfires are usually based on the detection of Planckian energy emissions in the MIR (3–5 μm), LWIR (8–14 μm) and/or SWIR (1.0–2.5 μm) spectral regions. However, vegetation also contains a series of trace elements which present unique narrowband spectral emission lines in the visible and near infrared wavelength range when the biomass is heated to high temperatures during the process of flaming combustion. These spectral lines can be discriminated by detector systems that are less costly than the longer wavelength, actively cooled instruments more typically used in EO-based active fire studies. The main trace element resulting in the appearance of spectral emission lines appears to be potassium (K), with features at 766.5 nm and 769.9 nm. Here we study K-emission line spectral signature in laboratory scale fires using a field spectrometer, at a series of moderately-sized woodland and shrubland fires using airborne imagery from a new compact hyperspectral imager (HYPER–SIM.GA) operating at a relatively fine spectral sampling interval (1.2 nm), and at large open wildfires using the EO-1 satellite's Hyperion sensor. We derive a metric based on band differencing of the spectral signal both close to and outside of the K-line region in order to quantify the magnitude of the K-emission signature, and find that variations in this metric appear to track quite well with the commonly used measures of fire radiometric temperature and fire radiative power (FRP). We find that substantial flaming activity is required to generate a potassium emission signature, but that once present this can be detected using airborne remote sensing even through a substantial smoke layer that apparently obscures fire across the remainder of the VIS spectral range. Being specific to flaming combustion, detection of the K-emission line signature could prove useful in refining estimates of the gases released in open wildfires, since trace gas emission factors can vary substantially between flaming and smouldering stages. Finally, we demonstrate the first identification of the K-emission line signature from space using the EO-1 Hyperion instrument, but find it detectable only in certain instances. We conclude that a finer spectral and spatial resolution than that offered by Hyperion is required for improved detection performance. Nevertheless, our results point to the potential effectiveness of airborne and spaceborne K-emission signature detection as a complement to the more common thermal remote sensing approaches to wildfire detection and analysis. Sensors targeting this application should consider careful placement of the measurement wavelengths around the location of the K-line wavelengths, in part to minimise influences from the nearby oxygen A-band features.

A calibration method has been applied on satellite data in the visible infrared spectral range from which spectral reflectance and emissivity may be retrieved. This dissertation describes the steps needed for multispectral/hyperspectral data calibration and a number of algorithms for reflectance and emissivity retrieval. The methodology is applied to retrieve reflectance and emissivity of volcano Teide and is validated through a comparison with “ground truth”. The “ground truth” spectra have been acquired during a field campaign carried on September 2007. As application of calibrated-validated data, the classification of the volcano Teide and the temperature map are discussed.

E' stato avviato un progetto pilota di didattica sperimentale dedicato alla scuola dell’infanzia che permettesse un primo approccio da parte dei bambini al mondo delle Scienze della Terra e a tutte le sue implicazioni. Il progetto ha riscosso molto successo, soprattutto ottenendo riscontri importanti che hanno aiutato anche nel miglioramento della divulgazione in questa fascia di età.

Mediterranean countries have always been affected by wildfires. However, global warming and more frequent hot summers increase the intensity, extension and impact of wildfires and may induce a shift in fire season. Earth Observing (EO) programs such as MODIS, VIRSS, and Sentinel 3 provide valuable information for wildfire detection due to daily overpass and thermal spectral bands, while Sentinel 2 (10-20m/px) and Landsat 8 (30m/px) data can provide more detailed information on small size wildfires and their impact on the ecosystem. In 2018 the ECOsystem Spaceborne Thermal Radiometer Experiment (ECOSTRESS) was deployed on the International Space Station (ISS) in order to provide temperature and evapotraspiration maps of vegetation to be used to detect vegetation water stress at its early stage and provide useful information for decision makers. The instrument has 70 m spatial resolution with 5 thermal spectral bands in the 8-12.5 μm range and an additional band at 1.6 um for geolocation and cloud detection. To minimize the electronic noise the focal plane is cooled by two commercial Thales cryocoolers. Two on board black bodies: one controlled between 16C to 24C and one controlled to 46C are used for calibration. The present study, carried out within the Early Adopter Program, aims to explore how ECOSTRESS data can provide, besides its primary mission, information on active fire that can complement fire characteristics derived by other programs such as Copernicus and Landsat. We examined La Drova wildfire, in Spain that ignited on 6 August 2018 and lasted 4 days. The fire was the result of 11separated fires and went rapidly out of control. 800 fire-fighters and soldiers and 30 helicopters and small aircraft were needed for the suppression while 2500 people were evacuated ECOSTRESS imagery was acquired on 8 August 2018 while the fire was still active. Sentinel 2 and Landsat 8 images acquired during the fire were cloudy. A pre- and post-fire cloud-free Sentinel 2 pair was used for NDVI and burn severity, and these were used for comparison with the ECOSTRESS image. Figure 1 (a) shows the ECOSTRESS image over La Drova fire processed by using band rationing tecnique. We adopted this tecnique to highlight clouds and active fire. Note that the burned area was clearly delineated as the fire is still active; unburned regions within the burn scar were identified with good agreement with vegetated (unburned) areas retrieved using high resolution NDVI (10m/px) derived from Sentinel 2 imagery acquired on 24 August 2018.

t This paper deals with detection and temperature analysis and of wildfires using PRISMA imagery. Precursore IperSpettrale della Missione Applicativa (Hyperspectral Precursor of the Application Mission, PRISMA) is a new hyperspectral mission by ASI (Agenzia Spaziale Italiana, Italian Space Agency) launched in 2019. This mission provides hyperspectral images with a spectral range of 400–2,500 nm and an average spectral resolution less than 12 nm and a spatial resolution of 30 m/pixel. This study focuses on the wildfire temperature estimation over the Bootleg Fire, US 2021. The analysis starts by considering the Hyperspectral Fire Detection Index (HFDI) which is used to analyze the informative content of the images, along with the analysis of some specific visible, near-infrared and shortwave-infrared bands. This first analysis is used as input to perform a temperature estimation of the areas with active wildfire. Surface temperature is retrieved using PRISMA radiance and a linear mixing model based on two background components (vegetation and burn scar) and two active fire components. PRISMA temperatures are compared with LST (Land Surface Temperature) products from NASA's ECOSTRESS and Landsat 8 which imaged the Bootleg Fire before and after PRISMA. A critical discussion of the results obtained with PRISMA is presented, followed by the advantages and limitation of the proposed approach.

This work is an evaluation, to which degree geological information can be obtained from modern remote sensing systems like the multispectral ASTER or the hyperspectral Hyperion sensor for a volcanic region like Teide Volcano (Tenerife, Canary Islands). The Canarian Arcipelago is made up of seven islands that represent different stages of geologic evolution. Tenerife is the central island of archipelago and has developed within the complex formed by the rifts associated with the Teide-Pico Viejo (T-PV-Lat 28° 16’ 30” Lon 16°38’ 42”) stratovolcanoes that reach a height of 3718 m, 7500 above the ocean floor. It is an active, though currently quiescent shield volcano, which last erupted in 1909. In the frame of the European Project FP6 PREVIEW-EURORISK (PREVention, Information and Early Warning pre-operational services to support the management of risks) (http://www.preview-risk.com/) a field campaign was carried out on Tenerife island to improve the retrieval algorithms and techniques, a field campaign has been realized on Pico de Teide (Tenerife island - Spain) from the 16th and 24th of September 2007. The validation campaign has been performed in order to acquire spectra used as ground truth data on the Pico de Teide in an area also know as Las Canadas Caldera (LCC). The time window was chosen taking into account different factor as: meteorological characterization, satellites scheduled passage, availability of both on Tenerife and INGV team. The measurements were localized on the summit area of the Tenerife Island and in particular within the Teide Caldera in order to identify suitable test sites both for cal/val activities and to study the geological setting of Pico the Teide volcano by image spectroscopy. Measurements in situ of reflectance and emissivity were realized very close/close the satellite passages. During the campaign atmospheric profiles and ground atmospheric measurements were acquired contemporaneously with the satellite acquisitions. A characterization of reflectance at summit crater surfaces was realised in order to complete the spectral characterization of different surfaces. The spectral measurements have been used as “ground truth” to realise the first classification map by satellite data of Teide volcano. In particular, the Support Vector Machine (SVM) supervised method has been applied to both ASTER and Hyperion data. The results are compared and discussed in this work.

We have studied the inland disastrous evidences of the tsunami triggered by the earthquake (M 9.0) occurred on March 11th, 2011 (at 05:46:23 UTC) offshore the coast of Honshu island (Japan). This large earthquake has been generated along the subduction plate boundary between the Pacific and the North America plates. The followed destructive tsunami caused casualties and severe damages along the coastline of most of Honshu Island. The dataset used in this work is composed of data in the visible spectral range, provided by ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) and Hyperion sensors, while for the microwave we have taken advantage of the active sensors such as Synthetics Aperture Radar (SAR). The large amount of data available from different sensors onboard of different satellite missions have allowed to sample the gradual tsunami inundation receding during the days soon after it occurred. Unsupervised and supervised algorithms have been applied for land cover classification purposes, identifying and mapping the extent of the effects caused by the tsunami on the different land cover classes present on the scene nearby the Sendai coast. The change classes, which have been identified, are in particular the stressed vegetation, the structural/house damage, the flooded areas, the debris, the sand deposits and boulders. The synoptic view, which is peculiar of remote sensing satellite data, DTM analysis and the information extracted from such a broad spectral range data have allowed an analysis of the tsunami characteristics phenomenon, such as the minimum inundation distance and the minimum run-up, respect to physical characters of the coastal area, such as topography, vegetation coverage and coastal orientation. This study would contribute to the definition of the susceptible level of the coastal region to get devastated by tsunami wave.

We present the Messinian evaporite suite (Mediterranean region) and the Solfatara hydrothermal system (Phlegraean Fields volcanic province, Italy), discuss their implications for understanding the origin of sulfates on Mars and show preliminary sets of VNIR laboratory and in situ reflectance spectra of rocks from these geologic systems. The choice was based on a number of evidence relative to Mars: (1) the chemistry of the Martian sulfates, suggesting fluid interactions with possibly alkali-basaltic rocks and/or regolith; (2) close range evidence of sulfates within sedimentary formations on Mars; (3) sulfate spectral signatures associated to large-scale layered patterns interpreted as thick depositional systems on Mars. The Messinian evaporites comprise three units: primary shallow-water sulfates (primary lower gypsum: PLG), shallow- to deep-water mixed sulfates and clastic terrigenous deposits (resedimented lower gypsum: RLG), and shallow-water associations of primary sulfates and clastic fluvio-deltaic deposits (upper evaporites: UE). The onset of the Messinian evaporites records the transition to negative hydrologic budget conditions associated with the Messinian Salinity Crisis, which affected the entire Mediterranean basin and lasted about 640 kyr. The Solfatara is a still evolving hydrothermal system that provides epithermal deposits precipitated from the interaction of fluids and trachybasaltic to phonolitic rocks. Thermal waters include alkali-chloride, alkali-carbonate and alkalisulfate endmembers. The wide spectrum of sedimentary gypsum facies within the Messinian formation includes some of the depositional environments hitherto identified on Mars and others not found on Mars. The PLG unit includes facies associations correlated over long distances, that could be a possible analog of the stratified rock units exposed from Arabia Terra at least as far as Valles Marineris. The facies cycles within the UE unit can be compared to the sequences of strata observed in craters such as Holden and Eberswalden. The UE unit records paleoenvironmental changes which are ultimately controlled by terrestrial climatic variations. They can be considered as a reliable climatic proxy and may be useful for the reconstruction of climatic events on Mars. The intermediate Messinian RLG unit has not, at present, a well-defined depositional counterpart on Mars, although there are some similarities with the northern lowlands and Vastitas Borealis Formation. The dramatic variation of hydrologic budget conditions at the onset of the Messinian evaporites may provide criteria for the interpretation of similar variations on Mars. The volcanic rocks at the Solfatara bear some similarities with the ‘‘alkaline magmatic province’’ observed at the Gusev crater on Mars, and the assemblages of hydrothermal phases resulting from the Solfatara’s parent rocks could be analogues for processes involving Gusev-type rocks. The Messinian sulfates have a prevalent Ca-sulfatic composition and wide textural variability. Preliminary laboratory reflectance spectra of rock samples in the VNIR region reveal the signature of sulfates and mixtures of several Fe-bearing phases. At the Solfatara, in situ reflectance measurements of epithermal minerals close to active fumaroles showed the presence of Fe-bearing sulfates,hematite, Al- and K-sulfates and abundant amorphous fraction. XRD analysis supported this interpretation. The range of depositional facies observed in the Messinian units and the variety of minerals detected in the Solfatara will be useful for the interpretation of close range data of Mars. The spectral characterization at various scales of the Messinian sedimentary facies and the Solfatara hydrothermal minerals will both help in the exploration of Mars from orbit and with close range inspection