Search results for "Correction"
showing 10 items of 601 documents
Mode-superposition correction method for deterministic and stochastic analysis of structural systems
2001
The role played by the modal analysis in the framework of structural dynamics is fundamental from both deterministic and stochastic point of view. However the accuracy obtained by means of the classical modal analysis is not always satisfactory. Therefore it is clear the importance of methods able to correct the modal response in such a way to obtain the required accuracy. Many methods have been proposed in the last years but they are meaningful only when the forcing function is expressed by an analytical function. Moreover in stochastic analysis they fail for white noise excitation. In the paper a method able to give a very accurate response for both deterministic and stochastic input is p…
Unveiling the strong interaction among hadrons at the LHC
2020
One of the key challenges for nuclear physics today is to understand from first principles the effective interaction between hadrons with different quark content. First successes have been achieved using techniques that solve the dynamics of quarks and gluons on discrete space-time lattices1,2. Experimentally, the dynamics of the strong interaction have been studied by scattering hadrons off each other. Such scattering experiments are difficult or impossible for unstable hadrons3–6 and so high-quality measurements exist only for hadrons containing up and down quarks7. Here we demonstrate that measuring correlations in the momentum space between hadron pairs8–12 produced in ultrarelativistic…
Data service platform for sentinel-2 surface reflectance and value-added products: System use and examples
2016
This technical note presents the first Sentinel-2 data service platform for obtaining atmospherically-corrected images and generating the corresponding value-added products for any land surface on Earth (http://s2.boku.eodc.eu/). Using the European Space Agency’s (ESA) Sen2Cor algorithm, the platform processes ESA’s Level-1C top-of-atmosphere reflectance to atmospherically-corrected bottom-of-atmosphere (BoA) reflectance (Level-2A). The processing runs on-demand, with a global coverage, on the Earth Observation Data Centre (EODC), which is a public-private collaborative IT infrastructure in Vienna (Austria) for archiving, processing, and distributing Earth observation (EO) data (http://www.…
Gradient-Based Automatic Lookup Table Generator for Radiative Transfer Models
2022
Physically based radiative transfer models (RTMs) are widely used in Earth observation to understand the radiation processes occurring on the Earth’s surface and their interactions with water, vegetation, and atmosphere. Through continuous improvements, RTMs have increased in accuracy and representativity of complex scenes at expenses of an increase in complexity and computation time, making them impractical in various remote sensing applications. To overcome this limitation, the common practice is to precompute large lookup tables (LUTs) for their later interpolation. To further reduce the RTM computation burden and the error in LUT interpolation, we have developed a method to automaticall…
Atmospheric components determination from ground-level measurements during the spectra Barax Campaigns (SPARC) field campaigns
2007
The Surface Processes and Ecosystem Changes Through Response Analysis (SPECTRA) Barrax Campaigns were validation campaigns developed in the framework of the SPECTRA mission in order to verify that the geophysical data products provided by satellite imagery are consistent with the measurements made by independent means. Two campaigns took place in Barrax, Spain, during the summers of 2003 and 2004. This paper presents the results of the characterization of the atmospheric composition from solar radiation, radiosoundings, and lidar measurements. Several potentially interesting situations involving atmospheric layers with different types of aerosols and water content are discussed. The presenc…
First results from the PROBA/CHRIS hyperspectral/multiangular satellite system over land and water targets
2005
The Project for On-Board Autonomy (PROBA) platform developed by the European Space Agency was launched on October 22, 2001. The instrument payload includes the Compact High Resolution Imaging Spectrometer (CHRIS). The coupled system provides high spatial resolution hyperspectral/multi-angular data, which represents a new-generation source of information for Earth observation purposes. The first results obtained from the preprocessing (noise removal and geometric/atmospheric correction) of two different datasets, collected over agricultural crops and inland waters, are presented in this letter. In situ measurements are used to assess the quality of the data and to validate the processing alg…
CHRIS/PROBA toolbox for hyperspectral and multiangular data exploitations
2009
The project CHRIS/Proba Toolbox for BEAM (CHRIS-Box) has been developed in order to support users of data from the CHRIS sensor onboard of ESA's Proba platform. BEAM and the CHRIS-Box are user tools which ESA/ESRTN are providing free of charge to the Earth Observation Community. The CHRIS-Box software provides extensions for BEAM that allows accomplishing the following tasks: a) Noise reduction to remove the vertical striping and other noise present in CHRIS response-corrected images; b) Cloud screening to mark cloudy pixels in CHRIS noise-corrected images; the cloud screening algorithm provides cloud probability and abundances for each pixel; c) Atmospheric correction that provides surface…
Desarrollo de productos avanzados para la misión SEOSAT/Ingenio
2016
SEOSAT/Ingenio es la futura misión española de observación de la Tierra en el óptico en alta resolución espacial. Mientras que los productos de imagen a Nivel 1, radiancias geo-referenciadas a nivel de sensor, se encuentran en una fase avanzada de desarrollo existiendo para ello un contrato industrial, los productos de Nivel 2 deben ser desarrollados por los propios usuarios. Este hecho limita el uso de las imágenes a la comunidad científica, restringiendo sus posibles aplicaciones fuera de ésta. Así pues, bajo el marco de un proyecto coordinado y motivados por ofrecer productos de Ingenio/SEOSAT de Nivel 2 a disposición de cualquier usuario, se origina y desarrolla este trabajo. En este ar…
Stock earnings and bond yields in the US 1871–2017 : The story of a changing relationship
2021
Abstract Using historical data spanning almost 150 years, we examine whether there is a long-run equilibrium relationship between the stock's earnings and bond yields. The novelty of our econometric methodology consists in using a vector error correction model where we allow multiple structural breaks in the equilibrium relationship. The results of our analysis suggest the existence of an equilibrium relationship over 1871–1932 and 1958–2017. On the two historical segments, our analysis finds that the stock's earnings yield followed the bond yield in both the short run and long run, but not the other way around. Perhaps the most important and surprising finding of our empirical study is tha…
- EL EFECTO FISHER Y LA PARIDAD DE INTERÉS REAL. EVIDENCIA PARA LA ECONOMÍA ESPAÑOLA
1999
This paper provides an empirical test of the Fisher effect and of the real interest parity. The objetive is to determinate the behavior of the ex-ante real interest that condicionate the intertemporal savings and investment decisions. The method used is the time series properties of the data, which allows to separate estimation of the long-run equilibrium relationship from the nuisance parameters that characterize the short-run dynamics. The results find support inthe long run for a tax-adjusted Fisher hypothesis but not for the real interest parity. En este trabajo se contrasta empíricamente el cumplimiento de la hipótesis de Fisher y de la paridad de interés real para el caso español. El …