English
Related papers

Related papers: Classifying Signatures of Sudden Ionospheric Distu…

200 papers

The largely unexplored decameter radio band (10-30 MHz) provides a unique window for studying a range of astronomical topics, such as auroral emission from exoplanets, inefficient cosmic ray acceleration mechanisms, fossil radio plasma, and…

Radio Frequency Interference (RFI) is emitted from various sources, terrestrial or orbital, and create a nuisance for ground-based 21cm experiments. In particular, single-dish 21cm intensity mapping experiments will be highly susceptible to…

Since the Solar Dynamics Observatory (SDO) began recording ~ 1 TB of data per day, there has been an increased need to automatically extract features and events for further analysis. Here we compare the overall detection performance,…

Solar and Stellar Astrophysics · Physics 2011-09-05 Cis Verbeeck , Paul A. Higgins , Tufan Colak , Fraser T. Watson , Veronique Delouille , Benjamin Mampaey , Rami Qahwaji

When monitoring geophysical parameters, data from segments that are contaminated by noise may have to be abandoned. This is the case, for example, in the geoelectrical field measurements at some sites in Japan, where high noise -due mainly…

Geophysics · Physics 2017-04-12 P. A. Varotsos , N. V. Sarlis , E. S. Skordas

With the widespread use of machine learning for classification, it becomes increasingly important to be able to use weaker kinds of supervision for tasks in which it is hard to obtain standard labeled data. One such kind of supervision is…

Machine Learning · Computer Science 2020-02-05 Soham Dan , Han Bao , Masashi Sugiyama

In this paper, we consider random phase fluctuations imposed during wave propagation through a turbulent plasma (e.g. ionosphere) as a source of additional noise in interferometric visibilities. We derive expressions for visibility variance…

Instrumentation and Methods for Astrophysics · Physics 2015-12-02 H. K. Vedantham , L. V. E. Koopmans

Ionospheric effects degrade the quality of radar data, which are critical for the precision of the satellite ephemeris produced by space surveillance systems; this degradation is especially noticeable for radars such as GRAVES that operate…

Faraday rotation of polarized emission from pulsars measured at radio frequencies provides a powerful tool to investigate the interstellar and interplanetary magnetic fields. However, besides being sensitive to the astrophysical media,…

We train a deep learning artificial neural network model, Spatial Attention U-Net to recover useful ionospheric signals from noisy ionogram data measured by Hualien's Vertical Incidence Pulsed Ionospheric Radar. Our results show that the…

We study the nature of quiet-Sun oscillations using multi-wavelength observations from TRACE, Hinode, and SOHO. The aim is to investigate the existence of propagating waves in the solar chromosphere and the transition region via analyzing…

Solar and Stellar Astrophysics · Physics 2012-09-27 G. R. Gupta , S. Subramanian , D. Banerjee , M. S. Madjarska , J. G. Doyle

Solar flares are energetic events in the solar atmosphere that are often linked with solar radio bursts (SRBs). SRBs are observed at metric to decametric wavelengths and are classified into five spectral classes (Type I--V) based on their…

Solar and Stellar Astrophysics · Physics 2023-06-28 Jeremiah Scully , Ronan Flynn , Peter Gallagher , Eoin Carley , Mark Daly

In challenging environments where traditional sensing modalities struggle, in-air sonar offers resilience to optical interference. Placing a priori known landmarks in these environments can eliminate accumulated errors in autonomous mobile…

Robotics · Computer Science 2024-12-23 Wouter Jansen , Jan Steckel

The noise in the depth profiles of secondary ion mass spectrometry (SIMS) is studied using different samples under various experimental conditions. Despite the noise contributions from various parts of the dynamic SIMS process, its overall…

Materials Science · Physics 2009-10-28 D. P. Chu , M. G. Dowsett , G. A. Cooke

A systematic study of ionospheric scintillation at the low-latitudes, especially around the Equatorial Ionization Anomaly (EIA) and the magnetic equator, is essential in understanding the dynamics of ionospheric variation and related…

Space Physics · Physics 2022-09-08 Deepthi Ayyagari , Abhirup Datta , Sumanjit Chakraborty

Several light pollution indicators are commonly used to monitor the effects of the transition from outdoor lighting systems based on traditional gas-discharge lamps to solid-state light sources. In this work we analyze a subset of these…

Instrumentation and Methods for Astrophysics · Physics 2019-09-25 Salvador Bará , Iago Rigueiro , Raul C. Lima

We demonstrate that extremely rapid and weak periodic and non-periodic signals can easily be detected by using the autocorrelation of intensity as a function of time. We use standard radio-astronomical observations that have artificial…

Instrumentation and Methods for Astrophysics · Physics 2018-05-16 Ermanno F. Borra , Jonathan D. Romney , Eric Trottier

While the {\it Helioseismic and Magnetic Imager} (HMI) onboard the {\it Solar Dynamics Observatory} (SDO) provides Doppler velocity [$V$], continuum intensity [$I_C$], and line-depth [$Ld$] observations, each of which is sensitive to the…

Solar and Stellar Astrophysics · Physics 2015-09-24 Rachel Howe , Kiran Jain , Richard S. Bogart , Deborah A. Haber , Charles S. Baldner

Sunquakes are seismic emissions visible on the solar surface, associated with some solar flares. Although discovered in 1998, they have only recently become a more commonly detected phenomenon. Despite the availability of several manual…

Solar and Stellar Astrophysics · Physics 2022-12-14 Vanessa Mercea , Alin Razvan Paraschiv , Daniela Adriana Lacatus , Anca Marginean , Diana Besliu-Ionescu

Tsunamis can trigger internal gravity waves (IGWs) in the ionosphere, perturbing the Total Electron Content (TEC) - referred to as Traveling Ionospheric Disturbances (TIDs) that are detectable through the Global Navigation Satellite System…

Machine Learning · Computer Science 2023-08-10 Valentino Constantinou , Michela Ravanelli , Hamlin Liu , Jacob Bortnik

We find that sensory noise delivered together with a weak periodic signal not only enhances nonlinear response of neuronal networks, but also improves the synchronization of the response to the signal. We reveal this phenomenon in neuronal…

Neurons and Cognition · Quantitative Biology 2015-08-25 M. A. Lopes , K. -E. Lee , A. V. Goltsev , J. F. F. Mendes