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NASA's Solar Dynamics Observatory (SDO) mission gathers 1.4 terabytes of data each day from its geosynchronous orbit in space. SDO data includes images of the Sun captured at different wavelengths, with the primary scientific goal of…

Image and Video Processing · Electrical Eng. & Systems 2023-05-05 Ali Zafari , Atefeh Khoshkhahtinat , Piyush M. Mehta , Nasser M. Nasrabadi , Barbara J. Thompson , Daniel da Silva , Michael S. F. Kirk

Weakly supervised object localization (WSOL) relaxes the requirement of dense annotations for object localization by using image-level classification masks to supervise its learning process. However, current WSOL methods suffer from…

Computer Vision and Pattern Recognition · Computer Science 2021-12-30 Lei Zhu , Qi She , Qian Chen , Xiangxi Meng , Mufeng Geng , Lujia Jin , Zhe Jiang , Bin Qiu , Yunfei You , Yibao Zhang , Qiushi Ren , Yanye Lu

Observational cosmology is entering an era in which high precision will be required in both measurement and data analysis. Accuracy, however, can only be achieved with a thorough understanding of potential sources of contamination from…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-19 Assaf Ben-David , Sebastian von Hausegger , Andrew D. Jackson

One of the main obstacles in exoplanet detection when using the radial velocity (RV) technique is the presence of stellar activity signal induced by magnetic regions. In this context, a realistic simulated dataset that can provide…

Solar and Stellar Astrophysics · Physics 2025-01-29 Yinan Zhao , Xavier Dumusque , Michael Cretignier , Khaled Al Moulla , Momo Ellwarth , Ansgar Reiners , Alessandro Sozzetti

Using wavelet analysis approach, the temporal variations of solar activity on time scales ranging from days to decades, are examined from the daily time series of sunspot numbers. A hierarchy of changing complex periods are careful detected…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Stefano Sello

Total and spectral solar irradiance are key parameters in the assessment of solar influence on changes in the Earth's climate. We present a reconstruction of daily solar irradiance obtained using the SATIRE-S model spanning 1974 to 2013…

Solar and Stellar Astrophysics · Physics 2015-07-07 K. L. Yeo , N. A. Krivova , S. K. Solanki , K. H. Glassmeier

To create early warning capabilities for upcoming Space Weather disturbances, we have selected a dataset of 61 emerging active regions, which allows us to identify characteristic features in the evolution of acoustic power density to…

Solar and Stellar Astrophysics · Physics 2024-12-25 Spiridon Kasapis , Irina N. Kitiashvili , Alexander G. Kosovichev , John T. Stefan , Bhairavi Apte

The Sky Brightness Monitor (SBM) is an important instrument to measure the brightness level for the sky condition, which is a critical parameter for judging a site for solar coronal observations. In this paper we present an automatic method…

Solar and Stellar Astrophysics · Physics 2015-06-22 M. Y. Zhao , Y. Liu , A. Elmhamdi , A. S. Kordi , H. A. Al-trabulsy , X. F. Zhang , T. F. Song , S. Q. Liu , Y. D. Shen , Z. J. Tian , Y. H. Miao

The solar cycle periodically reshapes the magnetic structure and radiative output of the Sun and determines its impact on the heliosphere roughly every 11 years. Besides this main periodicity, it shows century-long variations (including…

Solar and Stellar Astrophysics · Physics 2022-03-23 A. Munoz-Jaramillo , J. M. Vaquero

There are significant advantages in combining Hinode observations with ground-based instruments that can observe additional spectral diagnostics at higher data rates and with greater flexibility. However, ground-based observations, because…

Instrumentation and Methods for Astrophysics · Physics 2009-09-09 Kevin P. Reardon , Thomas Rimmele , Alexandra Tritschler , Gianna Cauzzi , Friedrich Woeger , Han Uitenbroek , Saku Tsuneta , Thomas Berger

We investigate a scenario where a chaser spacecraft or satellite equipped with a monocular camera navigates in close proximity to a target spacecraft. The satellite's primary objective is to construct a representation of the operational…

Robotics · Computer Science 2025-01-22 Lorenzo Ticozzi , Panagiotis Tsiotras

Given its unchallenged capabilities in terms of sensitivity and spatial resolution, the combination of imaging spectropolarimetry and numeric Stokes inversion represents the dominant technique currently used to remotely sense the physical…

Instrumentation and Methods for Astrophysics · Physics 2019-11-05 Francisco A. Iglesias , Alex Feller

Magnetic features on the surfaces of cool stars cause variations of their brightness. Such variations have been extensively studied for the Sun. Recent planet-hunting space telescopes allowed measuring brightness variations in hundred…

Solar and Stellar Astrophysics · Physics 2020-04-15 N. -E. Nèmec , A. I. Shapiro , N. A. Krivova , S. K. Solanki , R. V. Tagirov , R. H. Cameron , S. Dreizler

The Sun provides an excellent natural laboratory for nonlinear phenomena. We use motions of magnetic bright points on the solar surface, at the smallest scales yet observed, to study the small scale dynamics of the photospheric plasma. The…

Astrophysics · Physics 2009-11-06 J. K. Lawrence , A. C. Cadavid , A. Ruzmaikin , T. E. Berger

The Interferometric Bidimensional Spectrometer (IBIS) installed at the Dunn Solar Telescope of the NSO/SP is used to investigate the morphology and dynamics of the lower chromosphere and the virtually non-magnetic fluctosphere below. The…

Solar and Stellar Astrophysics · Physics 2014-11-20 F. Wöger , S. Wedemeyer-Böhm , H. Uitenbroek , T. R. Rimmele

The Simons Observatory (SO) Small Aperture Telescopes (SATs) will observe the Cosmic Microwave Background (CMB) temperature and polarization at six frequency bands. Within these bands, the angular response of the telescope (beam) is…

The weak-field approximation is one of the simplest models that allows us to relate the observed polarization induced by the Zeeman effect with the magnetic field vector present on the plasma of interest. It is usually applied for…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. Asensio Ramos

Synoptic magnetograms provide us with knowledge about the evolution of magnetic fields on the solar surface and present important information for forecasting future solar activity. In this work, poloidal and toroidal magnetic field…

Solar and Stellar Astrophysics · Physics 2020-02-19 Irina N. Kitiashvili

The all-sky 408 MHz map of Haslam et al. is one the most important total-power radio surveys. It has been widely used to study diffuse synchrotron radiation from our Galaxy and as a template to remove foregrounds in cosmic microwave…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. Remazeilles , C. Dickinson , A. J. Banday , M. -A. Bigot-Sazy , T. Ghosh

While the quiet Sun magnetic field shows only little variation with the solar cycle, long-term variations cannot be completely ruled out from first principles. We investigate the potential effect of quiet Sun magnetism on spectral solar…

Solar and Stellar Astrophysics · Physics 2020-06-05 M. Rempel