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The signal demixing problem seeks to separate a superposition of multiple signals into its constituent components. This paper studies a two-stage approach that first decompresses and subsequently deconvolves the noisy and undersampled…

Information Retrieval · Computer Science 2022-05-25 Zhenan Fan , Halyun Jeong , Babhru Joshi , Michael P. Friedlander

We present the first results from a programme of multi-frequency simultaneous single pulse observations carried out as part of the European Pulsar Network. We detail the main data analysis methods and apply them to simultaneous observations…

It is widely believed that range resolution, the ability to distinguish between two closely situated targets, depends inversely on the bandwidth of the transmitted radar signal. Here we demonstrate a different type of ranging system, which…

Signal Processing · Electrical Eng. & Systems 2021-06-30 Rony Komissarov , Vitali Kozlov , Dmitry Filonov , Pavel Ginzburg

Spatial field correlation functions represent a key quantity for the description of mesoscopic phenomena in disordered media and the optical characterization of complex materials. Yet many aspects related to the vector nature of light waves…

Optics · Physics 2014-02-03 Kevin Vynck , Romain Pierrat , Rémi Carminati

For light fields, the manifestation of correlations between fluctuating electric field components at different space-time points is referred to as coherence, whereas these correlations appearing between orthogonal electric field components…

Optics · Physics 2019-02-07 Bhaskar Kanseri , Sethuraj K. R

The complete characterization of spatial coherence is difficult because the mutual coherence function is a complex-valued function of four independent variables. This difficulty limits the ability of controlling and optimizing spatial…

Pulsed UV lasers can provide useful "testbeams" for observatories that use optical detectors, especially fluorescence detectors, to measure high energy cosmic-rays. The light observed by the detector is proportional to the energy of the…

Instrumentation and Methods for Astrophysics · Physics 2011-05-23 Lawrence Wiencke , Fernando Arqueros , John Compton , Maria Monasor , David Pilger , Jaime Rosado

We designed and built a new astronomical photo-polarimeter that can measure linear polarization simultaneously in three spectral bands. It has a Calcite beamdisplacement prism as the analyzer. The ordinary and extra-ordinary emerging beams…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 G. Srinivasulu , A. V. Raveendran , S. Muneer , M. V. Mekkaden , N. Jayavel , M. R. Somashekar , K. Sagayanathan , S. Ramamoorthy , M. J. Rosario , K. Jayakumar

The nature of coherent radio emission is still challenging even after more than half a century of pulsar discovery, but it is generally a consensus that single-pulse observations are essential for probing the magnetospheric dynamics,…

High Energy Astrophysical Phenomena · Physics 2026-05-11 Shunshun Cao , Yanjun Guo , Jinchen Jiang , Kejia Lee , Weiyang Wang , Renxin Xu

We apply the theory of high-order harmonic generation by low-frequency laser fields in the strong field approximation to the study of the spatial and temporal coherence properties of the harmonics. We discuss the role of dynamically induced…

Quantum Physics · Physics 2007-05-23 Pascal Salières , Anne L'Huillier , Philippe Antoine , Maciej Lewenstein

This paper presents a new approach for tackling the shift-invariance problem in the discrete Haar domain, without trading off any of its desirable properties, such as compression, separability, orthogonality, and symmetry. The paper…

Computer Vision and Pattern Recognition · Computer Science 2017-05-23 Mais Alnasser , Hassan Foroosh

A statistical framework is presented for the study of the orthogonally polarized modes of radio pulsar emission via the covariances between the Stokes parameters. To accommodate the typically heavy-tailed distributions of single-pulse radio…

Instrumentation and Methods for Astrophysics · Physics 2017-02-07 Willem van Straten , Caterina Tiburzi

We present here a direct comparison of the polarisation position angle (PA) profiles of 17 pulsars, observed at 1.4 and 3.1 GHz. Absolute PAs are obtained at each frequency, permitting a measurement of the difference in the profiles. By…

Astrophysics · Physics 2016-08-30 A. Karastergiou , S. Johnston

We have examined data from pulsars B0950+08 and B0329+54 for evidence of temporally coherent radiation using the modified coherence function (MCF) technique of Jenet et al. (2001). We consider the influence of both instrumental bandpass and…

Astrophysics · Physics 2009-11-07 J. M. Smits , B. W. Stappers , J-P. Macquart , R. Ramachandran , J. Kuijpers

We present a new extensive analysis of the old problem of finding a satisfactory calibration of the relation between the geometric albedo and some measurable polarization properties of the asteroids. To achieve our goals, we use all…

Earth and Planetary Astrophysics · Physics 2015-06-02 A. Cellino , S. Bagnulo , R. Gil-Hutton , P. Tanga , M. Canada-Assandri , E. F. Tedesco

Aims: To propose a method for the polarimetric calibration of large astronomical mirrors that does not require use of special optical devices nor knowledge of the exact polarization properties of the calibration target. Methods: We study…

Instrumentation and Methods for Astrophysics · Physics 2015-11-11 A. Lopez Ariste

The ability of NICMOS to perform high accuracy polarimetry is currently hampered by an uncalibrated residual instrumental polarization at a level of 1.2-1.5%. To better quantify and characterize this residual we obtained observations of…

In this paper, we propose a new form of polarization reconfigurable antennas (PRAs) that can form linear, circular, and general elliptical polarizations assisted by phase shifters (PSs). With PRAs, polarforming is achieved, which enables…

Signal Processing · Electrical Eng. & Systems 2025-05-29 Zijian Zhou , Jingze Ding , Rui Zhang

The multi-dithering method has been well verified in phase locking of polarization coherent combination experiment. However, it is hard to apply to low repetition frequency pulsed lasers, since there exists an overlap frequency domain…

Signal Processing · Electrical Eng. & Systems 2022-03-10 Jiali Zhang , Jie Cao , Qun Hao , Yang Cheng , Liquan Dong , Bin Han , Xuesheng Liu

In this paper we present a differential approach to photo-polarimetric shape estimation. We propose several alternative differential constraints based on polarisation and photometric shading information and show how to express them in a…

Computer Vision and Pattern Recognition · Computer Science 2017-08-28 Silvia Tozza , William A. P. Smith , Dizhong Zhu , Ravi Ramamoorthi , Edwin R. Hancock