Search results for " Global sensitivity analysis"

showing 3 items of 3 documents

Global Sensitivity Analysis of Leaf-Canopy-Atmosphere RTMs: Implications for Biophysical Variables Retrieval from Top-of-Atmosphere Radiance Data.

2019

Knowledge of key variables driving the top of the atmosphere (TOA) radiance over a vegetated surface is an important step to derive biophysical variables from TOA radiance data, e.g., as observed by an optical satellite. Coupled leaf-canopy-atmosphere Radiative Transfer Models (RTMs) allow linking vegetation variables directly to the at-sensor TOA radiance measured. Global Sensitivity Analysis (GSA) of RTMs enables the computation of the total contribution of each input variable to the output variance. We determined the impacts of the leaf-canopy-atmosphere variables into TOA radiance using the GSA to gain insights into retrievable variables. The leaf and canopy RTM PROSAIL was coupled with…

010504 meteorology & atmospheric sciencesradiative transfer models0211 other engineering and technologiesemulation02 engineering and technologytop-of-atmosphere radiance data01 natural sciencesEmulation; Global sensitivity analysis; Machine learning; MODTRAN; PROSAIL; Radiative transfer models; Retrieval; Sentinel-2; Top-of-atmosphere radiance dataKrigingRange (statistics)Radiative transferLeaf area indexlcsh:Scienceretrieval021101 geological & geomatics engineering0105 earth and related environmental sciencesRemote sensingMODTRANPROSAILMODTRANAtmospheric correctionradiative transfer models; global sensitivity analysis; emulation; machine learning; top-of-atmosphere radiance data; PROSAIL; MODTRAN; retrieval; Sentinel-2machine learningglobal sensitivity analysisLookup tableRadianceGeneral Earth and Planetary SciencesEnvironmental sciencelcsh:QSentinel-2Remote sensing
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Sensitivity analysis: fundamentals

2015

Sensitivity analysis (SA) is a valuable tool to support the use of mathematical models for environmental systems. Local or global SA (namely, LSA and GSA) are performed in order to better understand processes and to select the most influential factors affecting processes. The main objective of this extended abstract is to provide an informed problem statement of the issues surrounding LSA and GSA applications in the environmental water quality modelling field. Specifically, this paper aims at identifying, for the most popular methods, their potential use, the critical issues to be solved and the limits identified in a comprehensive literature review.

Settore ICAR/03 - Ingegneria Sanitaria-AmbientaleLocal sensitivity analysis Global sensitivity analysis water treatment calibration
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Emulation of Leaf, Canopy and Atmosphere Radiative Transfer Models for Fast Global Sensitivity Analysis

2016

Physically-based radiative transfer models (RTMs) help understand the interactions of radiation with vegetation and atmosphere. However, advanced RTMs can be computationally burdensome, which makes them impractical in many real applications, especially when many state conditions and model couplings need to be studied. To overcome this problem, it is proposed to substitute RTMs through surrogate meta-models also named emulators. Emulators approximate the functioning of RTMs through statistical learning regression methods, and can open many new applications because of their computational efficiency and outstanding accuracy. Emulators allow fast global sensitivity analysis (GSA) studies on adv…

PROSPECTSAIL010504 meteorology & atmospheric sciencesradiative transfer modelsScience0211 other engineering and technologies02 engineering and technologyemulatorSolar irradiance01 natural sciencessymbols.namesakeRadiative transferSensitivity (control systems)Gaussian process021101 geological & geomatics engineering0105 earth and related environmental sciencesRemote sensingMathematicsMODTRANArtificial neural networkMODTRANQDiffuse sky radiationemulator; global sensitivity analysis; machine learning; radiative transfer models; PROSPECT; SAIL; MODTRANmachine learningglobal sensitivity analysisRadiancesymbolsGeneral Earth and Planetary SciencesRemote Sensing
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