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We present a novel method for forecasting key ionospheric parameters using transformer-based neural networks. The model provides accurate forecasts and uncertainty quantification of the F2-layer peak plasma frequency (foF2), the F2-layer…

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…

An accuracy of the last version of International Reference Ionosphere IRI-2001 at low latitudes is tested by a detailed comparison of longitudinal variations in the equatorial anomaly development following from this model with the ones…

Space Physics · Physics 2008-05-09 Yurii V. Dumin

This study explores the use of historical data from Global Navigation Satellite System (GNSS) scintillation monitoring receivers to predict the severity of amplitude scintillation, a phenomenon where electron density irregularities in the…

Signal Processing · Electrical Eng. & Systems 2024-09-04 Sultan Halawa , Maryam Alansaari , Maryam Sharif , Amel Alhammadi , Ilias Fernini

This manuscript analyzes IONORT-ISP-WC, an advanced ionospheric ray-tracing tool improving HF radio wave propagation predictions. It significantly upgrades IONORT-ISP by integrating a double-exponential collision frequency model for the…

Geophysics · Physics 2025-07-01 Alessandro Settimi

We use deep spectroscopy from the SAMI Galaxy Survey to explore the precision of the fundamental plane of early-type galaxies (FP) as a distance indicator for future single-fibre spectroscopy surveys. We study the optimal trade-off between…

Faraday rotation measurements using the current and next generation of low-frequency radio telescopes will provide a powerful probe of astronomical magnetic fields. However, achieving the full potential of these measurements requires…

A number of hardware upgrades for the Low-Frequency Array (LOFAR) are currently under development. These upgrades are collectively referred to as the LOFAR 2.0 upgrade. The first stage of LOFAR 2.0 will introduce a distributed clock signal…

Instrumentation and Methods for Astrophysics · Physics 2021-08-11 H. W. Edler , F. de Gasperin , D. Rafferty

The QUIJOTE MFI instrument (2012-2018) observed the sky at four frequency bands, namely 11, 13, 17 and 19GHz, at 1 degree angular resolution. Using around 10000 h of observations in the so-called nominal mode, QUIJOTE MFI produced sky maps…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-16 Apolline Chappard , José Alberto Rubiño-Martín , Ricardo Tanausú Génova-Santos

We use information theory to derive fundamental limits on the capacity to calibrate next-generation radio interferometers, and measure parameters of point sources for instrument calibration, point source subtraction, and data deconvolution.…

Instrumentation and Methods for Astrophysics · Physics 2012-12-11 Cathryn M. Trott , Randall B. Wayth , Steven J. Tingay

We use the high-resolution Swarm faceplate plasma density data at 16 Hz to develop a set of parameters that can characterize multi-scale ionospheric structures and irregularities along the Swarm orbit. We present the methods for calculating…

The ionosphere is the main driver of a series of systematic effects that limit our ability to explore the low frequency (<1 GHz) sky with radio interferometers. Its effects become increasingly important towards lower frequencies and are…

Instrumentation and Methods for Astrophysics · Physics 2018-08-08 F. de Gasperin , M. Mevius , D. A. Rafferty , H. T. Intema , R. A. Fallows

Acoustic wave heating is believed to contribute significantly to the missing energy input required to maintain the solar chromosphere in its observed state. We studied the propagation of waves above the acoustic cutoff in the upper…

Solar and Stellar Astrophysics · Physics 2023-03-29 Momchil E. Molnar , Kevin P. Reardon , Steven R. Cranmer , Adam F. Kowalski , Ivan Milic

The time evolution of a large-amplitude electromagnetic (EM) wave injected vertically into the overhead ionosphere is studied numerically. The EM wave has a carrier frequency of 5 MHz and is modulated as a Gaussian pulse with a width of…

Plasma Physics · Physics 2015-06-26 Bengt Eliasson , Bo Thidé

Calibration of radio interferometric observations becomes increasingly difficult towards lower frequencies. Below ~300 MHz, spatially variant refractions and propagation delays of radio waves traveling through the ionosphere cause phase…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 H. T. Intema , S. van der Tol , W. D. Cotton , A. S. Cohen , I. M. van Bemmel , H. J. A. Rottgering

The determination of the cutoff frequency in real solar observations under different local physical conditions is an important and insufficiently explored aspect of waves in solar physics. This work utilizes the near ultraviolet (NUV)…

Solar and Stellar Astrophysics · Physics 2026-05-14 Pradeep Kayshap , Gayathri Hegde , Z. E. Musielak , Kris Murawski , Tobıas Felipe

Detection of the global HI 21 cm signal from Cosmic Dawn and Epoch of Reionization is the key science driver for several ongoing ground-based and future ground/space-based experiments. The crucial spectral features in the global 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-11 Abhirup Datta , Richard Bradley , Jack O. Burns , Geraint Harker , Attila Komjathy , T. Joseph W. Lazio

Detection of redshifted \ion{H}{i} 21-cm emission is a potential probe for investigating the Universe's first billion years. However, given the significantly brighter foreground, detecting 21-cm is observationally difficult. The Earth's…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-30 Anshuman Tripathi , Abhirup Datta , Madhurima Choudhury , Suman Majumdar

Radio resource management in cellular networks is typically based on device measurements reported to the serving base station. Frequent measuring of signal quality on available frequencies would allow for highly reliable networks and…

Applications · Statistics 2019-03-04 Caroline Svahn , Oleg Sysoev , Mirsad Čirkić , Fredrik Gunnarsson , Joel Berglund

The specification of the upper atmosphere strongly relies on solar proxies that can properly reproduce the solar energetic input in the UV. Whilst the microwave flux at 10.7 cm (also called F10.7 index) has been routinely used as a solar…

Solar and Stellar Astrophysics · Physics 2014-02-18 Thierry Dudok de Wit , Sean Bruinsma , Kiyoto Shibasaki
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