Vincenzo Cuomo

Evaluation of a new satellite-based method for forest fire detection

Advanced Very High Resolution Radiometer (AVHRR)-based fire detection methods are considered in this work in order to assess their effective usefulness in the framework of civil programmes for fire risk and damage mitigation. The discussion is divided into the evaluation of the most commonly used methods and the description of a new fire detection procedure which is proposed in this paper. Commonly used detection methods are based on using absolute threshold values for decision tests. These values usually match only with very local, uniform (in space and time) situations, and are often inadequate when applied to heterogeneous, or simply different, geographical areas or seasons. A high number of false alarms, so high as to make the satellite-based product not operationally utilizable, is the main disadvantage of the fixed-threshold approach. The new fire-detection procedure proposed here makes use only of historical AVHRR data in order to automatically produce local (in space and time) threshold values, suitable for fire-event detection also in very critical situations. High fire discrimination capabilities with low false-alarm rates, simple unsupervised implementation and, above all, flexibility for automatic extension to completely different geographic areas and observation conditions, are the main advantages associated with this new technique. Results obtained for different Italian areas have been successfully compared with ground observations made by the Italian Forestry Service. Tests made over a long observation period show that, on cloud-free regions, more than 75% of significant forest fires are detected with less than 20% of false alarms.

A new approach to investigate the correlation between geoelectrical time fluctuations and earthquakes in a seismic area of southern Italy

We propose a new approach to investigate the possible correlation between electrical signals and earthquakes. Good correlation has been found between the spectral power-law exponent of geoelectrical signals and the Hurst exponent of the seismicity of the area investigated. A tendency of both parameters to converge toward unity, typical of self-organized critical dynamics, is evident before the occurrence of the major event recorded in the area during the observation period.

Identifying space–time clustering properties of the 1983–1997 Irpinia–Basilicata (Southern Italy) seismicity

Abstract The fractality of the earthquake sequence (1983–1997) of Irpinia–Basilicata (Southern Italy), one of the most seismically active regions of the Mediterranean area, has been analysed by temporal and spatial fractal tools. The fractal exponent α , estimated by the Allan Factor method, characterises the time-clustering behaviour of the set of earthquakes, while the correlation dimension D C , calculated by means of the correlation integral method, gives information on the space-clustering behaviour of the sequence of seismic events. Analysing the variations of both the parameters, we recognised the presence of a strong space–time clusterisation associated with the major events that occurred in the investigated area.

A self-adaptive algorithm based on AVHRR multitemporal data analysis for small active fire detection

The present study proposes and improved self-adaptive algorithm (ISAA) for the detection of active fires using only channel 3 data of the Advanced Very High Resolution Radiometer (AVHRR). ISAA is specifically devised for the detection of small fires. The fire detection procedure is mainly based on the multitemporal approach (TN-ALT) devised by Cuomo et al . (2001a) and makes use of statistical analyses of real fires from different regions of the Italian peninsula. Such analyses allow the characterization of these fires as well as the computation of dynamic threshold values, which are variable in time and space and calibrated on local environmental conditions. ISAA was developed using an initial data sample of 1000 fires that occurred in 1996, and then in order to achieve a highly satisfactory performance in fire detection, the statistical analyses are updated yearly, so that a wider data sample can be considered for subsequent years. The evaluation tests made use of multitemporal satellite data (from 1997 to 1999) and ground observations provided by the Italian Forestry Service. The results obtained in different regions of North and South Italy demonstrated that ISAA detected about 80% of fires (with a low rate of false alarms at 15%) and showed a high fire discrimination capability both in the worst and good light conditions. The most recent contextual methods of fire detection were applied to significant test cases and compared with the results obtained from ISAA. This comparison showed that ISAA was able to find an increased number of fires as well as to reduce false alarms in all different light conditions.

Depth‐dependent time‐clustering behaviour in seismicity of southern California

Temporal fluctuations in seismicity of southern California have been investigated by means of two methods, the Allan Factor Analysis and the Detrended Fluctuation Analysis, which are used to detect the scaling behaviour of an nonstationary observational time series. Performing the time-clustering analysis varying the depth of the events, we found that the seismicity of the area reveals a tendency toward Poissonian behaviour near the depth ranges 14–16 km.

EAQUATE: An International Experiment For Hyperspectral Atmospheric Sounding Validation

The international experiment called the European Aqua Thermodynamic Experiment (EAQUATE) was held in September 2004 in Italy and the United Kingdom to validate Aqua satellite Atmospheric Infrared Sounder (AIRS) radiance measurements and derived products with certain groundbased and airborne systems useful for validating hyperspectral satellite sounding observations. A range of flights over land and marine surfaces were conducted to coincide with overpasses of the AIRS instrument on the Earth Observing System Aqua platform. Direct radiance evaluation of AIRS using National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) and the Scanning High-Resolution Infrared Sounder has shown excellent agreement. Comparisons of level-2 retrievals of temperature and water vapor from AIRS and NAST-I validated against high-quality lidar and dropsonde data show that the 1-K/l-km and 10%/1-km requirements for temperature and water vapor (respectively) are ge...

Detection of interannual variation of vegetation in middle and southern Italy during 1985–1999 with 1 km NOAA AVHRR NDVI data

The potential of NOAA-advanced very high resolution radiometer (AVHRR) time series for environmental studies was investigated at the pixel scale. We analyzed a multitemporal set of annual maximum value composite (MVC) of normalized difference vegetation index. Local area coverage data of middle and southern Italy were processed from measurements taken between 1985 and 1999 of the afternoon viewing of NOAA 9, 11, and 14. Significant artificial anomalies were found due to satellite switch, short-wave calibration instability and illumination effects. We removed such systematic errors and achieved a strong reduction of standard deviation values (around 50%). Interesting results were obtained from a change detection analysis performed at the pixel level. Outcomes from satellite-based analysis were compared with independent time series data, such as ancillary meteorological data, forest fire archives, and results from field surveys. Results showed that the geographical areas where MVC data indicated a decrease in vegetation activity match well with areas affected by forest fires, intense human activity, or rapid decline of coniferous forests. In contrast, an increase in MVC was found in regions recently involved in a growth of intensive farming or invaded by alien plants which are now recognized as a threat to native species. Our exploratory results indicate that high-quality AVHRR data can profitably support studies on interannual dynamics of surface parameters. In particular, our parameterization of illumination and calibration adjustments can be directly applied to Mediterranean-like ecosystems.

Breadboard of a Fourier-transform spectrometer for the Radiation Explorer in the Far Infrared atmospheric mission

In preparation for a possible space mission, a breadboard version named REFIR-BB of the Radiation Explorer in the Far Infrared (REFIR) instrument has been built. The REFIR is a Fourier-transform spectrometer with a new optical layout operating in the spectral range 100-1100 cm(-1) with a resolution of 0.5 cm(-1), a 7-s acquisition time, and a signal-to-noise ratio of better than 100. Its mission is the spectral measurement in the far infrared of the Earths outgoing emission, with particular attention to the long-wavelength spectral region, which is not covered by either current or planned space missions. This measurement is of great importance for deriving an accurate estimate of the radiation budget in both clear and cloudy conditions. The REFIR-BB permits the trade-off among all instrument parameters to be studied, the optical layout to be tested, and the data-acquisition strategy to be optimized. The breadboard could be used for high-altitude ground-based campaigns or could be flown for test flights on aircraft or balloon stratospheric platforms. The breadboards design and the experimental results are described, with particular attention to the acquisition strategy and characterization of the interferometer. Tests were performed both in laboratory conditions and in vacuum. Notwithstanding a loss of efficiency above 700 cm(-1) caused by the poor performance of the photolithographic polarizers used as beam splitters, the results demonstrate the feasibility of using the spectrometer for space applications.

Transport infrastructure surveillance and monitoring by electromagnetic sensing: the ISTIMES project

The ISTIMES project, funded by the European Commission in the frame of a joint Call “ICT and Security” of the Seventh Framework Programme, is presented and preliminary research results are discussed. The main objective of the ISTIMES project is to design, assess and promote an Information and Communication Technologies (ICT)-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring of critical transport infrastructures. The integration of electromagnetic technologies with new ICT information and telecommunications systems enables remotely controlled monitoring and surveillance and real time data imaging of the critical transport infrastructures. The project exploits different non-invasive imaging technologies based on electromagnetic sensing (optic fiber sensors, Synthetic Aperture Radar satellite platform based, hyperspectral spectroscopy, Infrared thermography, Ground Penetrating Radar-, low-frequency geophysical techniques, Ground based systems for displacement monitoring). In this paper, we show the preliminary results arising from the GPR and infrared thermographic measurements carried out on the Musmeci bridge in Potenza, located in a highly seismic area of the Apennine chain (Southern Italy) and representing one of the test beds of the project.

Retrieval of foreign-broadened water vapor continuum coefficients from emitted spectral radiance in the H2O rotational band from 240 to 590 cm −1

The paper presents a novel methodology to retrieve the foreign-broadened water vapor continuum absorption coefficients in the spectral range 240 to 590 cm(-1) and is the first estimation of the continuum coefficient at wave numbers smaller than 400 cm(-1) under atmospheric conditions. The derivation has been accomplished by processing a suitable set of atmospheric emitted spectral radiance observations obtained during the March 2007 Alps campaign of the ECOWAR project (Earth Cooling by WAter vapor Radiation). It is shown that, in the range 450 to 600 cm(-1), our findings are in good agreement with the widely used Mlawer, Tobin-Clough, Kneizys-Davies (MT CKD) continuum. Below 450 cm(-1) however the MT CKD model overestimates the magnitude of the continuum coefficient.