Search results for " mappe"

Mapping burns and natural reforestation using thematic Mapper data

1991

Abstract Remote sensing techniques are specially suitable to detect and to map areas affected by forest fires. In this work, Landsat 5 Thematic Mapper (TM) data has been used to study a number of forest fires that occurred in the province of Valencia (Spain) and to monitor the vegetation regeneration over burnt areas. A reference area (non‐burnt forest) was established to assess the change produced by fire. The radiance in the thermal band (10.4–12.5 μm) and the normalized difference in reflectance between near 1R (0.76–0.90 μm) and middle IR (2.08–2.35 μm) were the most suitable parameters to map burnt areas. This index can also be used for monitoring vegetation regeneration in burnt areas…

Identità e alterità. Il lungo viaggio di Gabriella Ghermandi, Cristina Ali Farah, Igiaba Scego, Ornela Vorpsi

2015

L’analisi parallela delle opere di quattro scrittrici della migrazione consente di individuare, nella singolarità delle scritture, una circolarità di discorso sui temi del viaggio e dello spaesamento, del racconto e della lingua.. Il saggio mette in evidenza come lo «statuto relazionale dell’identità» viva in rapporto a quello dell’alterità e si configuri come un’identità multipla che si realizza in uno spazio mobile. Il lungo viaggio di Gabriella Ghermandi, Cristina Ali Farah, Igiaba Scego e Ornela Vorpsi illustra, con diversi esiti, la trasformazione del tema dell’esilio in quello della perenne erranza. Dalla loro esperienza della migrazione, dalla loro condizione nomade, emergono narrazi…

Assessment of workflow feature selection on forest LAI prediction with sentinel-2A MSI, landsat 7 ETM+ and Landsat 8 OLI

2020

The European Space Agency (ESA)’s Sentinel-2A (S2A) mission is providing time series that allow the characterisation of dynamic vegetation, especially when combined with the National Aeronautics and Space Administration (NASA)/United States Geological Survey (USGS) Landsat 7 (L7) and Landsat 8 (L8) missions. Hybrid retrieval workflows combining non-parametric Machine Learning Regression Algorithms (MLRAs) and vegetation Radiative Transfer Models (RTMs) were proposed as fast and accurate methods to infer biophysical parameters such as Leaf Area Index (LAI) from these data streams. However, the exact design of optimal retrieval workflows is rarely discussed. In this study, the impact of…

A Simultaneous Observation of Lightning by ASIM, Colombia-Lightning Mapping Array, GLM, and ISS-LIS

2021

The Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS) provides optical radiances and images of lightning flashes in several spectral bands. This work presents a lightning flash simultaneously observed from space by ASIM, the Geostationary Lightning Mapper (GLM) and the Lightning Imaging Sensor on the International Space Station (ISS-LIS); and from ground by the Colombia-Lightning Mapping Array (Colombia-LMA). Volumetric weather radar provides reflectivity data to help to interpret the effects of the cloud particles on the observed optical features. We found that surges in radiance in the band at 777.4 nm appear to be related mostly with lightning processe…

Comparison of high‐speed optical observations of a lightning flash from space and the ground

2020

We analyze a nighttime negative cloud-to-ground lightning flash in Colombia observed from the ground with a high-speed camera at 5,000 images per second and from space by the Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS), the Lightning Imaging Sensor also on the ISS (ISS-LIS), and the Geostationary Lightning Mapper (GLM) on GOES-16. The space instruments measure the oxygen band at 777.4 nm, allowing for direct comparisons of measurements, and the ground-based camera observes in a wide visible band. After conversion to energy emitted at the cloud top, we find a good linear correspondence of the optical energies measured by the three space instruments, …

Modalità “orientata sul partecipante” in siciliano contemporaneo: un’analisi dei dati dell’Atlante linguistico della Sicilia (ALS)

Evaluation of the AVHRR surface reflectance long term data record between 1984 and 2011

2021

Abstract The long-term data record (LTDR) from the Advanced Very High-Resolution Radiometer (AVHRR) provides daily surface reflectance with global coverage from the 1980s to present day, making it a unique source of information for the study of land surface properties and their long-term dynamics. Surface reflectance is a critical input for the generation of products such as vegetation indices, albedo, and land cover. Therefore, it is of utmost importance to quantify its uncertainties to better understand how they might propagate into downstream products. Due to the prolonged length of the surface reflectance LTDR and previous unavailability of a well calibrated reference, no comprehensive …

Radiometric correction effects in Landsat multi‐date/multi‐sensor change detection studies

2006

Radiometric corrections serve to remove the effects that alter the spectral characteristics of land features, except for actual changes in ground target, becoming mandatory in multi‐sensor, multi‐date studies. In this paper, we evaluate the effects of two types of radiometric correction methods (absolute and relative) for the determination of land cover changes, using Landsat TM and Landsat ETM+ images. In addition, we present an improvement made to the relative correction method addressed. Absolute correction includes a cross‐calibration between TM and ETM+ images, and the application of an atmospheric correction protocol. Relative correction normalizes the images using pseudo‐invariant fe…

Relation between reflectance of rice crop and indices of pollution by heavy metals in soils of albufera natural park (Valencia, Spain)

1993

13 páginas, 3 figuras, 4 tablas, 1 foto.

Il sostenibile ossimoro del GIS qualitativo

2017

The Sustainable Oxymoron of Qualitative GIS This paper discusses the idea of a qualitative GIS, by presenting an experiment held in Palermo during the last few years. It first presents a theoretical framework on the shifting paradigms concerning maps and GIS, and then introduces the current debate on mixing qualitative and quantitative data and techniques of analysis in GIScience. By collecting mental maps representing the neighbourhoods of Palermo and inserting them within a traditional GIS structure, the author has warped these traditional representations in order to obtain a map which is less technically accurate, yet more complying with the perception of the citizens. These operations h…