Search results for "Spectral"

Mapping sub-pixel burnt percentage using AVHRR data. Application to the Alcalaten area in Spain

2010

The purpose of this work is to estimate at sub-pixel scale the percentage of burnt land using the Advanced Very High Resolution Radiometer AVHRR through a simple approach. This methodology is based on multi-temporal spectral mixture analysis MSMA, which uses a normalized difference vegetation index NDVI and a land-surface temperature LST image as input bands. The area of study is located in the Alcalaten region in Castellon Spain, a typical semi-arid Mediterranean region. The results have shown an extension of approximately 55 km2 affected by fire, which is only 5% lower than the statistic reports provided by the Environmental Ministry of Spain. Finally, we include a map of the area showing…

Cross-correlation and cross-power spectral density representation by complex spectral moments

2017

Abstract A new approach to provide a complete characterization of normal multivariate stochastic vector processes is presented in this paper. Such proposed method is based on the evaluation of the complex spectral moments of the processes. These quantities are strictly related to the Mellin transform and they are the generalization of the integer-order spectral moments introduced by Vanmarcke. The knowledge of the complex spectral moments permits to obtain the power spectral densities and their cross counterpart by a complex series expansions. Moreover, with just the aid of some mathematical properties the complex fractional moments permit to obtain also the correlation and cross-correlatio…

Riesz fractional integrals and complex fractional moments for the probabilistic characterization of random variables

2012

Abstract The aim of this paper is the probabilistic representation of the probability density function (PDF) or the characteristic function (CF) in terms of fractional moments of complex order. It is shown that such complex moments are related to Riesz and complementary Riesz integrals at the origin. By invoking the inverse Mellin transform theorem, the PDF or the CF is exactly evaluated in integral form in terms of complex fractional moments. Discretization leads to the conclusion that with few fractional moments the whole PDF or CF may be restored. Application to the pathological case of an α -stable random variable is discussed in detail, showing the impressive capability to characterize…

Free-atom—metal shifts in theM4,5N4,5N4,5Auger spectra of Ag, Cd, In, Sn, Sb, and Te

1981

The ‘Irving–Williams’ Order in the Metal-ligand Stretching Frequencies of Some Metal Hydrazine Complexes

1960

MANY infra-red spectra of metal complexes have been examined in the 2–15μ region, but until now very few co-ordination compounds have been studied in the caesium bromide region in which some metal-ligand atom-stretching frequencies are expected1. Furthermore, no correlation between the frequency of this vibration and the nature of the metal has been found2.

Wave energy assessment in Sicily (Italy)

2015

Abstract This research presents an estimation of wave energy potential in Sicily (Italy) carried out using both buoy wave measurements from Rete Ondametrica Nazionale (RON), the Italian Government wave buoy network, and wave parameter data by ERA-INTERIM, a recent meteorological reanalysis project of the European Centre for Medium-Range Weather Forecasts (ECMWF). Starting from these offshore data, we first identified the western part of Sicily as the area with a higher availability of offshore wave energy; subsequently, we selected a study area in the western part of the south coast and assessed the nearshore potential energy by performing propagation using a spectral model (SWAN). The near…

Comparison of evapotranspiration estimates by NOAA-AVHRR images and aircraft flux measurements in a semiarid region of Spain.

1998

Abstract This paper is intended to show how to aggregate two different remote-sensing techniques carried out in the framework of the European-Union funded project EFEDA (European Field Experiment in a Desertification-threatened Area). One of these is based on satellite measurements, and the other on aircraft flux measurements. The aim of putting together both methodologies was to determine regional evapotranspiration as a major component of the water balance in Castilla-La Mancha, a semiarid region in southeast Spain. The basis for the satellite approach is using temperature information collected by the Advanced Very High-Resolution Radio- meter (AVHRR) sensor on board the National Oceanic …

Hyperspectral solar spectral measurements and applications

2007

Measurements of hyperspectral solar irradiance from aircraft and satellite are applied to a variety of cloud and aerosol remote sensing, and radiative energy budget applications.

Actual evapotranspiration estimation by means of airborne and satellite remote sensing data

2006

ABSTRACT During the last the two decades, the scientific community developed detailed mathematical models for simulating land surface energy fluxes and crop evapotrans piration rates by means of a energy ba lance approach. These models can be applied in large areas and with a spatial distributed approach using surface brightness temperature and some ancillary data retrieved from satellite/airborne remote sensed imagery. In this paper a district scale application in combination with multispectral (LandaSat 7 TM data) and hyperspectral airborne MIVIS data has been carried out to test the potentialities of two different energy balance models to estimate evapotranspiration fluxes from a set of …

Statistical atmospheric parameter retrieval largely benefits from spatial-spectral image compression

2021

The infrared atmospheric sounding interferometer (IASI) is flying on board of the Metop satellite series, which is part of the EUMETSAT Polar System. Products obtained from IASI data represent a significant improvement in the accuracy and quality of the measurements used for meteorological models. Notably, the IASI collects rich spectral information to derive temperature and moisture profiles, among other relevant trace gases, essential for atmospheric forecasts and for the understanding of weather. Here, we investigate the impact of near-lossless and lossy compression on IASI L1C data when statistical retrieval algorithms are later applied. We search for those compression ratios that yield…