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Fourier representation (FR) is an indispensable mathematical formulation for modeling and analysis of physical phenomenon, engineering systems and signals in numerous applications. In this study, we present the generalized Fourier…

Signal Processing · Electrical Eng. & Systems 2020-08-28 Pushpendra Singh

Collaborative path planning for robot swarms in complex, unknown environments without external positioning is a challenging problem. This requires robots to find safe directions based on real-time environmental observations, and to…

Robotics · Computer Science 2025-01-03 Chenxi Li , Weining Lu , Zhihao Ma , Litong Meng , Bin Liang

Photospheric horizontal velocity fields play essential roles in the formation and evolution of numerous solar activities. Various methods for estimating the horizontal velocity field have been proposed in the past. Aiming at the highest…

Solar and Stellar Astrophysics · Physics 2026-01-27 Quan Xie , Jiajia Liu , Robert Erdélyi , Yuming Wang

Doppler radars are routinely used for the remote sensing of oceanic surface currents and atmospheric wind profiles. Even though they operate at different frequencies and address different media, they follow very similar processing for the…

Atmospheric and Oceanic Physics · Physics 2021-02-02 Baptiste Domps , Julien Marmain , Charles-Antoine Guérin

The large availability and rich spectral coverage of today's observational data of the solar corona, and the high spatial and temporal resolution of many instruments, has enabled the evolution of three-dimensional (3D) physical models to a…

Solar and Stellar Astrophysics · Physics 2015-03-10 Alberto Marcos Vásquez

Interferometers play an increasingly important role for spatially resolved observations. If employed at full potential, interferometry can probe an enormous dynamic range in spatial scale. Interpretation of the observed visibilities…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 C. Brinch , C. P. Dullemond

In the present paper, the wavelet transform of Fractal Interpolation Function (FIF) is studied. The wavelet transform of FIF is obtained through two different methods. The first method uses the functional equation through which FIF is…

Dynamical Systems · Mathematics 2012-06-21 Srijanani Anurag Prasad

Understanding the global rotational profile of the solar atmosphere and its variation is fundamental to uncovering a comprehensive understanding of the dynamics of the solar magnetic field and the extent of coupling between different layers…

Transient X-ray absorption techniques can measure ultrafast dynamics of the elemental edges in a material or multiple layer junction, giving them immense potential for deconvoluting concurrent processes. However, the interpretation of the…

Materials Science · Physics 2021-06-10 Hanzhe Liu , Isabel M. Klein , Jonathan M. Michelsen , Scott K. Cushing

The usual fluid equations describing the large-scale evolution of mass density in the universe can be written as local in the density, velocity divergence, and velocity potential fields. As a result, the perturbative expansion in small…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-01 Marcel Schmittfull , Zvonimir Vlah , Patrick McDonald

Optical spectrum analysis is the cornerstone of spectroscopic sensing, optical network performance monitoring, and hyperspectral imaging. While conventional high-performance spectrometers used to perform such analysis are often large…

Applied Physics · Physics 2018-03-19 Derek M. Kita , Brando Miranda , David Favela , David Bono , Jerome Michon , Hongtao Lin , Tian Gu , Juejun Hu

The Helioseismic Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) records line-of-sight Dopplergram images of convective flows on the surface. These images are used to obtain the multi-scale convective spectrum. We design…

Solar and Stellar Astrophysics · Physics 2021-08-09 Samarth G Kashyap , Shravan M Hanasoge

The appropriate weather prediction is a challenging task and it can be feasible with proper wind speed fluctuation analysis. In this current paper daubechies-4 wavelet is used to analyze the winter wind speed fluctuations due to lesser…

Computational Engineering, Finance, and Science · Computer Science 2016-12-06 Sabyasachi Mukhopadhyay , Prasanta K Panigrahi

We address the problem of discretizing continuous cosmological signals such as a galaxy distribution for further processing with Fast Fourier techniques. Discretizing, in particular representing continuous signals by discrete sets of sample…

Instrumentation and Methods for Astrophysics · Physics 2009-01-21 J. Jasche , F. S. Kitaura , T. A. Ensslin

Recent research in deep learning (DL) has investigated the use of the Fast Fourier Transform (FFT) to accelerate the computations involved in Convolutional Neural Networks (CNNs) by replacing spatial convolution with element-wise…

Computer Vision and Pattern Recognition · Computer Science 2024-06-05 Eduardo Reis , Thangarajah Akilan , Mohammed Khalid

Knowledge of the global magnetic field distribution and its evolution on the Sun's surface is crucial for modeling the coronal magnetic field, understanding solar wind dynamics, computing the heliospheric open flux distribution and…

Solar and Stellar Astrophysics · Physics 2024-09-24 Soumyaranjan Dash , Marc L. DeRosa , Mausumi Dikpati , Xudong Sun , Sushant S. Mahajan , Yang Liu , J. Todd Hoeksema

It is known that the continuous wavelet transform of a function $f$ decays very rapidly near the points where $f$ is smooth, while it decays slowly near the irregular points. This property allows one to precisely identify the singular…

Functional Analysis · Mathematics 2007-05-23 Gitta Kutyniok , Demetrio Labate

Solar flares are known to generate seismic waves in the Sun. We present a detailed analysis of seismic emission in sunspots accompanying M- and X-class solar flares. For this purpose, we have used high-resolution Dopplergrams and…

Solar and Stellar Astrophysics · Physics 2020-07-13 Hirdesh Kumar , Brajesh Kumar

In this paper, we analyze the probability density function (PDF) of solar wind velocity and proton density, based on generalized thermostatistics (GT) approach, comparing theoretical results with observational data. The time series analyzed…

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
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