Results 91 to 100 of about 152,938 (206)

Investigating Abiotic Sources of Spectral Variability From Multitemporal Hyperspectral Airborne Acquisitions Over the French Guyana Canopy

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Classifiers trained on airborne hyperspectral imagery are proficient in identifying tree species in hyperdiverse tropical rainforests. However, spectral fluctuations, influenced by intrinsic and environmental factors, such as the heterogeneity of ...
Colin Prieur, Antony Laybros, Giovanni Frati, Daniel Schlapfer, Jocelyn Chanussot, Gregoire Vincent   +5 more
doaj   +1 more source

ENERGY-DEPENDENT POWER SPECTRAL STATES AND ORIGIN OF APERIODIC VARIABILITY IN BLACK HOLE BINARIES

, 2013
We found that the black hole candidate MAXI J1659-152 showed distinct power spectra, i.e., power-law noise (PLN) versus band-limited noise (BLN) plus quasi-periodic oscillations (QPOs) below and above about 2 keV, respectively, in observations with Swift
Zhang, Wenda, Yu, Wenfei
core  

The Relation between Simulated Multiwavelength Blazar Variability and Stochastic Fluctuations

The Astrophysical Journal
Blazars exhibit multiwavelength variability, a phenomenon whose underlying mechanisms remain elusive. This study investigates the origin of such variability through leptonic blazar emission simulations, focusing on stochastic fluctuations in ...
Hannes Thiersen, Michael Zacharias, Markus Böttcher   +2 more
doaj   +1 more source

Advancements in solar spectral irradiance measurements by the TSIS-1 spectral irradiance monitor and its role for long-term data continuity

Journal of Space Weather and Space Climate
The first implementation of NASA’s Total and Spectral Solar Irradiance Sensor (TSIS-1) launched on December 15th, 2017, and was integrated into the International Space Station (ISS) to measure both the total solar irradiance (TSI) and the solar spectral ...
Richard Erik, Coddington Odele, Harber Dave, Chambliss Michael, Penton Steven, Brooks Keira, Charbonneau Luke, Peck Courtney, Béland Stéphane, Pilewskie Peter, Woods Tom   +10 more
doaj   +1 more source

Correlated Temporal and Spectral Variability [PDF]

AIP Conference Proceedings, 2007
The variability of neutron star and black hole X‐ray sources has several dimensions, because of the roles played by different important time‐scales. The variations on time scales of hours, weeks, and months, ranging from 50% to orders of magnitude, arise out of changes in the flow in the disk.
openaire   +1 more source

Characterizing CDOM Spectral Variability Across Diverse Regions and Spectral Ranges

, 2018
Satellite remote sensing of colored dissolved organic matter (CDOM) has focused on CDOM absorption (aCDOM) at a reference wavelength, as its magnitude provides insight into the underwater light field and large-scale biogeochemical processes.
Mouw, Colleen B., Grunert, Brice, Ciochetto, Audrey B., Brice K. Grunert, Audrey B. Ciochetto, Colleen B. Mouw, Grunert, Brice K.   +6 more
core   +1 more source

Considering spectral variability for optical material abundance estimation

, 2017
Hyperspectral images include information enabling the determination of material abundances. Due to the fact that the acquisition of hyperspectral images is time consuming and the processing of these images is computationally costly, we propose an optical
Krippner, Wolfgang, Fernando Puente León, Puente León, Fernando, Sebastian Bauer, Wolfgang Krippner, Bauer, Sebastian   +5 more
core   +1 more source

An extended spectral angle map for hyperspectral and multispectral imaging

We present an extension to the widely used spectral angle metric, calculating an azimuthal angle around a reference vector. We demonstrate that it provides additional information, thus improving the classification ability of the spectral ...
Rutt, Harvey, O'Sullivan, Jack, Hoy, Paul   +2 more
core  

Spectral Variability of Quasar SDSS J030639.57+000343.1

, 2014
In a sample of 60 quasars selected from the Sloan Digital Sky Survey (SDSS) with at least six-epoch spectroscopy, we investigated the variability of emission lines and continuum luminosity.
Gu, Minfeng, Guo, Hengxiao
core  

The nature of X-ray spectral variability in Seyfert galaxies

, 2003
We use a model-independent technique to investigate the nature of the 2–15 keV X-ray spectral variability in four Seyfert galaxies and distinguish between spectral pivoting and the two-component model for spectral variability.
Taylor, R.D., Uttley, P., McHardy, I.M.
core   +1 more source