Results 261 to 270 of about 2,215,341 (299)

Endmember Variability in Hyperspectral Analysis: Addressing Spectral Variability During Spectral Unmixing

IEEE Signal Processing Magazine, 2014
Variable illumination and environmental, atmospheric, and temporal conditions cause the measured spectral signature for a material to vary within hyperspectral imagery. By ignoring these variations, errors are introduced and propagated throughout hyperspectral image analysis.
Alina Zare
exaly   +3 more sources

Spectral variability of atlantic forest species

2013 IEEE International Geoscience and Remote Sensing Symposium - IGARSS, 2013
This paper investigates the spectral variability of Brazilian Atlantic Forest trees. Spectroscopy data (reflectance and transmittance) of full sunlight leaves were collected. The root mean square difference between pairs of spectra were used to estimate within- and between-species variability.
Matheus Pinheiro Ferreira, Atilio E. B. Grondona, Silvia Beatriz Alves Rolim, Yosio Edemir Shimabukuro   +3 more
openaire   +2 more sources

Rapid Spectral Variability of DR Tau

Astrophysics and Space Science, 1998
The Classical T Tauri stars (CTTS) are pre-main sequence stars surrounded by an accretion disk. Material from the disk is being accreted by the central object, probably by a strong magnetic field anchored to the star (Konigl 1991). The accreted material is channelled down the magnetic field lines and free falls onto the star’s surface, forming strong ...
K. W. Smith, G. F. Lewis, I. A. Bonnell, P. S. Bunclark, J. P. Emerson   +4 more
openaire   +1 more source

X-Ray Spectral Variability of 3C273

Space Science Reviews, 1985
3C273 has been monitored by EXOSAT over the period December 1983 to June 1984 in 4 observations. In the December observation the flux was high and the spectrum showed a power law index of 1.5 changing to 0.9 at~8 keV. In subsequent observations the flux dropped to~40% of its original value and the hard tail disappeared.
M.J.L. Turner, T. Courvoisier, R. Staubert, D. Molteni, J. Trumper   +4 more
openaire   +1 more source

Spectral variability of blazars

AIP Conference Proceedings, 2000
Broadband spectral characteristics of different subclasses of γ-ray blazars in different γ-ray intensity states are contrasted and discussed in the framework of currently popular leptonic jet models. Differences between quasars and BL-Lacs may be understood in terms of the dominance of different radiation mechanisms in the gamma-ray regime.
openaire   +1 more source

Spectral Variability of Light-Emitting Diodes with Angle

Conference on Colour in Graphics, Imaging, and Vision, 2010
Multispectral systems allow the spectral characterization of the scene through several acquisition channels with different spectral features. The spectral sampling can be done by using transmittance filters and a white light source or illuminating the scene using light sources with different spectral emission characteristics.
Martínez, Óscar, Vilaseca Ricart, Meritxell, Pizarro Bondia, Carlos, Ferrer, Edgard, Arjona Carbonell, Mª Montserrat, Pujol Ramo, Jaume   +5 more
openaire   +3 more sources