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Radar interferometry usually exploits two complex-valued radar images with the same resolution to extract terrain elevation information. This paper considers the interferometry using two radar images with different resolutions, which we…

Information Theory · Computer Science 2018-12-14 Huizhang Yang , Chengzhi Chen , Shengyao Chen , Feng Xi , Zhong Liu

The goal of synthetic aperture imaging is to estimate the reflectivity of a remote region of interest by processing data gathered with a moving sensor which emits periodically a signal and records the backscattered wave. We introduce and…

Image and Video Processing · Electrical Eng. & Systems 2019-07-05 Liliana Borcea , Josselin Garnier

In radio bands, the study of compact radio sources can be affected by propagation effects through the Interstellar Medium. These are usually attributed to the presence of turbulent intervening plasma along the line of sight. Here, two of…

Astrophysics · Physics 2013-09-26 K. É. Gabányi , S. Britzen , T. P. Krichbaum , U. Bach , L. Fuhrmann , A. Kraus , A. Witzel , J. A. Zensus

We propose a new method to detect gravitational waves, based on spatial coherence interferometry with stellar light, as opposed to the conventional temporal coherence interferometry with laser sources. The proposed method detects…

High Energy Astrophysical Phenomena · Physics 2021-11-09 I. H. Park , K. -Y. Choi , J. Hwang , S. Jung , D. H. Kim , M. H. Kim , C. -H. Lee , K. H. Lee , S. H. Oh , M. -G. Park , S. C. Park , A. Pozanenko , C. D. Rho , N. Vedenkin , E. Won

The role played by the intergalactic medium (IGM) in the X-ray absorption towards high-redshift sources has recently drawn more attention in spectral analysis studies. Here, we study the X-ray absorption towards 15 flat-spectrum radio…

High Energy Astrophysical Phenomena · Physics 2018-09-05 R. Arcodia , S. Campana , R. Salvaterra , G. Ghisellini

We use cyclic spectroscopy to perform high frequency-resolution analyses of multi-hour baseband Arecibo observations of the millisecond pulsar PSR B1937+21. This technique allows for the examination of scintillation features in far greater…

It was recently suggested by Boldyrev & Gwinn that the characteristics of radio scintillations from distant pulsars are best understood if the interstellar electron-density fluctuations that cause the time broadening of the radio pulses…

Astrophysics · Physics 2010-11-11 Stanislav Boldyrev , Arieh Konigl

In the framework of the study of extragalactic radio sources, we will focus on the importance of the spatial resolution at different wavelengths, and of the combination of observations at different frequency bands. In particular, a…

Astrophysics · Physics 2009-09-29 Gianfranco Brunetti

We propose a new approach, based on the Hanbury Brown and Twiss intensity interferometry, to transform a Cherenkov telescope to its equivalent optical telescope. We show that, based on the use of photonics components borrowed from…

Instrumentation and Methods for Astrophysics · Physics 2021-05-26 Pierre-Marie Gori , Farrokh Vakili , Jean-Pierre Rivet , William Guerin , Mathilde Hugbart , Andrea Chiavassa , Adrien Vakili , Robin Kaiser , Guillaume Labeyrie

Infrared-Faint Radio Sources (IFRS) represent an unexpected class of objects relatively bright at radio wavelength, but unusually faint at infrared (IR) and optical wavelengths. A recent and extensive campaign on the radio-brightest IFRSs…

Refractive interstellar scintillation (RISS) is thought to be the cause behind a variety of phenomena seen at radio wavelengths in pulsars and compact radio sources. Though there is substantial observational data to support several…

Astrophysics · Physics 2009-10-31 N. D. Ramesh Bhat , A. Pramesh Rao , Yashwant Gupta

With current wide-field near-infrared (NIR) instruments the scattered light in the near-infrared can be mapped over large areas. Below A_V ~ 10 the surface brightness is directly proportional to the column density, and at slightly higher…

Astrophysics · Physics 2009-11-11 M. Juvela , V. -M. Pelkonen , P. Padoan , K. Mattila

Stellar intensity interferometers correlate photons within their coherence time and could overcome the baseline limitations of existing amplitude interferometers. Intensity interferometers do not rely on phase coherence of the optical…

Instrumentation and Methods for Astrophysics · Physics 2022-02-24 Sebastian Karl , Andreas Zmija , Stefan Richter , Naomi Vogel , Dmitry Malyshev , Adrian Zink , Thilo Michel , Gisela Anton , Joachim von Zanthier , Stefan Funk

Context: Fast Radio Bursts are transient radio pulses from presumably compact stellar sources of extragalactic origin. With new telescopes detecting multiple events per day, statistical methods are required in order to interpret…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Stefan Hackstein , Marcus Brüggen , Franco Vazza , Luiz F. S. Rodrigues

We use the upgraded Giant Metrewave Radio Telescope to measure scintillation arc properties in six bright canonical pulsars with simultaneous dual frequency coverage. These observations at frequencies from 300 to 750 MHz allowed for…

High Energy Astrophysical Phenomena · Physics 2024-08-27 Jacob E. Turner , Bhal Chandra Joshi , Maura A. McLaughlin , Daniel R. Stinebring

The joint analysis of the Dispersion and Faraday Rotation Measure from distant, polarised Fast Radio Bursts may be used to put constraints on the origin and distribution of extragalactic magnetic fields on cosmological scales. While the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-24 F. Vazza , M. Brüggen , P. M. Hinz , D. Wittor , N. Locatelli , C. Gheller

We present new wideband radio observations with the Australia Telescope Compact Array of a sample of 12 giant radio galaxies. The radio observations are part of a larger radio-optical study aimed at relating the radio structures with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 J. M. Malarecki , L. Staveley-Smith , L. Saripalli , R. Subrahmanyan , D. H. Jones , A. R. Duffy , M. Rioja

This paper provides a theoretical analysis of diffraction-limited superresolution, demonstrating that arbitrarily close point sources can be resolved in ideal situations. Precisely, we assume that the incoming signal is a linear combination…

Optimization and Control · Mathematics 2015-08-14 Geoffrey Schiebinger , Elina Robeva , Benjamin Recht

Radio emission propagating over an Earth-pulsar line of sight provides a unique probe of the intervening ionized interstellar medium (ISM). Variations in the integrated electron column density along this line of sight, or dispersion measure…

High Energy Astrophysical Phenomena · Physics 2020-04-08 M. T. Lam , T. J. W. Lazio , T. Dolch , M. L. Jones , M. A. McLaughlin , D. R. Stinebring , M. Surnis

The spectrogram is a classical DSP tool used to view signals in both time and frequency. Unfortunately, the Heisenberg Uncertainty Principal limits our ability to use them for detecting and measuring narrowband signal modulation in wideband…

Information Theory · Computer Science 2014-01-22 Ray Maleh , Frank A. Boyle