نتایج جستجو برای: spectral indices

تعداد نتایج: 243566  

1996
R. Wielebinski

The radio continuum spectra of 74 galaxies were used to separate thermal and non-thermal radio emission. The thermal fraction f1GHz th at 1 GHz and the non-thermal spectral index αnth of the radio continuum emission were determined. The mean values are 〈f1GHz th 〉 = 0.08± 0.01 and 〈αnth〉 = 0.83± 0.02. Even at 10 GHz the radio continuum emission ofmost of the galaxies is dominated by the synchro...

Journal: :The Journal of trauma 2003
David G Jacobs Brian Ray Plaisier Philip S Barie Jeffrey S Hammond Michele R Holevar Karlene E Sinclair Thomas M Scalea Wendy Wahl

2000
I. Neill Reid

We present near-infrared (1 to 2.5 μm) low-resolution spectroscopy of eleven ultracool dwarfs with spectral types ranging from M7 to L8. Combining our observations with data published previously by Leggett et al. (2001), we have measured equivalent widths for the strongest atomic features and constructed narrowband indices to gauge the strength of the strongest molecular features. Those measure...

Journal: :Int. J. Applied Earth Observation and Geoinformation 2014
Xia Zhang Kun Shang Yi Cen Tong Shuai Yanli Sun

Coverage rates of vegetation and exposed bedrock are two key indicators of karst rocky desertification. In this study, the abundances of vegetation and exposed rock were retrieved from a hyperspectral Hyperion image using linear spectral unmixing method. The results were verified using the spectral indices of karst rocky desertification (KRDSI) and an integrated LAI spectral index: modified chl...

2007
Mercedes Mollá

We present a grid of 440 spectro-photometric models for simulating spiral and irregular galaxies. They have been consistently calculated with evolutionary synthesis models which use as input the information proceeding from chemical evolution models. The model predictions are spectral energy distributions, brightness and color profiles and radial distributions of spectral absorption stellar indi...

Journal: :Remote Sensing 2017
Thierry Erudel Sophie Fabre Thomas Houet Florence Mazier Xavier Briottet

This study aims to evaluate three classes of methods to discriminate between 13 peatland vegetation types using reflectance data. These vegetation types were empirically defined according to their composition, strata and biodiversity richness. On one hand, it is assumed that the same vegetation type spectral signatures have similarities. Consequently, they can be compared to a reference spectra...

2012
Mirwaes Wahabzada Kristian Kersting Christian Bauckhage Christoph Römer Agim Ballvora Francisco Pinto Uwe Rascher Jens Leon Lutz Ploemer

Understanding the adaptation process of plants to drought stress is essential in improving management practices, breeding strategies as well as engineering viable crops for a sustainable agriculture in the coming decades. Hyper-spectral imaging provides a particularly promising approach to gain such understanding since it allows to discover non-destructively spectral characteristics of plants g...

Journal: :Remote Sensing 2017
Camile Sothe Cláudia Maria de Almeida Veraldo Liesenberg Marcos Benedito Schimalski

Studies designed to discriminate different successional forest stages play a strategic role in forest management, forest policy and environmental conservation in tropical environments. The discrimination of different successional forest stages is still a challenge due to the spectral similarity among the concerned classes. Considering this, the objective of this paper was to investigate the per...

2015
Aaron Ball Arturo Sanchez-Azofeifa Carlos Portillo-Quintero Benoit Rivard Saulo Castro-Contreras Geraldo Fernandes

AIM The general goal of this study is to investigate and analyze patterns of ecophysiological leaf traits and spectral response among life forms (trees, shrubs and lianas) in the Cerrado ecosystem. In this study, we first tested whether life forms are discriminated through leaf level functional traits. We then explored the correlation between leaf-level plant functional traits and spectral refl...

1998
Rick L. Lawrence William J. Ripple

Spectral vegetation indices have been used extensively INTRODUCTION to predict ecological variables, such as percent vegetation On 18 May 1980, Mount St. Helens in the State of cover, above-ground biomass, and leaf-area index. We exWashington erupted with catastrophic, landscape-scale amined the use of various vegetation indices and multiple effects (Lipman and Mullineaux, 1981). In a mere 10 l...

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