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Adjusting for an unmeasured confounder is generally an intractable problem, but in the spatial setting it may be possible under certain conditions. In this paper, we derive necessary conditions on the coherence between the treatment…

Methodology · Statistics 2020-12-23 Yawen Guan , Garritt L. Page , Brian J Reich , Massimo Ventrucci , Shu Yang

In order to meet the theoretically achievable imaging performance, calibration of modern radio interferometers is a mandatory challenge, especially at low frequencies. In this perspective, we propose a novel parallel iterative…

Instrumentation and Methods for Astrophysics · Physics 2016-09-09 Martin Brossard , Mohammed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal , Stefan J. Wijnholds

Radio maps find numerous applications in wireless communications and mobile robotics tasks, including resource allocation, interference coordination, and mission planning. Although numerous techniques have been proposed to construct radio…

Signal Processing · Electrical Eng. & Systems 2022-01-14 Raju Shrestha , Daniel Romero , Sundeep Prabhakar Chepuri

Radio interferometers are phased arrays producing high-resolution images from the covariance matrix of measurements. Calibration of such instruments is necessary and is a critical task. This is how the estimation of instrumental errors is…

Instrumentation and Methods for Astrophysics · Physics 2023-09-26 Yassine Mhiri , Mohammed Nabil El Korso , Arnaud Breloy , Pascal Larzabal

It is known that the scan statistic with variable window size favors the detection of signals with small spatial extent and there is a corresponding loss of power for signals with large spatial extent. Recent results have shown that this…

Methodology · Statistics 2022-05-20 Guenther Walther

Spectral-spatial processing has been increasingly explored in remote sensing hyperspectral image classification. While extensive studies have focused on developing methods to improve the classification accuracy, experimental setting and…

Computer Vision and Pattern Recognition · Computer Science 2017-03-08 Jie Liang , Jun Zhou , Yuntao Qian , Lian Wen , Xiao Bai , Yongsheng Gao

The data reduction procedure for radio interferometers can be viewed as a combined calibration and imaging problem. We present an algorithm that unifies cross-calibration, self-calibration, and imaging. Being a Bayesian method, that…

Instrumentation and Methods for Astrophysics · Physics 2019-07-23 Philipp Arras , Philipp Frank , Reimar Leike , Rüdiger Westermann , Torsten Enßlin

This paper summarizes some of the major calibration and image reconstruction techniques used in radio interferometry and describes them in a common mathematical framework. The use of this framework has a number of benefits, ranging from…

Instrumentation and Methods for Astrophysics · Physics 2009-11-26 U. Rau , S. Bhatnagar , M. A. Voronkov , T. J. Cornwell

In radar systems, unimodular (or constant-modulus) waveform design plays an important role in achieving better clutter/interference rejection, as well as a more accurate estimation of the target parameters. The design of such sequences has…

Signal Processing · Electrical Eng. & Systems 2022-08-10 Shahin Khobahi , Arindam Bose , Mojtaba Soltanalian

Response calibration is the process of inferring how much the measured data depend on the signal one is interested in. It is essential for any quantitative signal estimation on the basis of the data. Here, we investigate self-calibration…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Torsten A. Enßlin , Henrik Junklewitz , Lars Winderling , Maksim Greiner , Marco Selig

The raw outputs of the detectors within the Advanced Laser Interferometer Gravitational-Wave Observatory need to be calibrated in order to produce the estimate of the dimensionless strain used for astrophysical analyses. The two detectors…

Differential Chromatic Refraction (DCR) is caused by the wavelength dependence of our atmosphere's refractive index, which shifts the apparent positions of stars and galaxies and distorts their shapes depending on their spectral energy…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Jaemyoung Jason Lee , Masao Sako , Richard Kessler , Alex I. Malz , The LSST Dark Energy Science Collaboration

Using the international ground-based network of two-frequency receivers of the GPS navigation system provides a means of carrying out a global, continuous and fully-computerized monitoring of phase fluctuations of signals from…

Geophysics · Physics 2007-05-23 E. L. Afraimovich , V. A. Karachenschev

Matter-wave interferometry with solids is highly susceptible to minute fluctuations of environmental fields, including gravitational effects from distant sources. Hence, experiments require a degree of shielding that is extraordinarily…

Quantum Physics · Physics 2022-08-23 Julen S. Pedernales , Martin B. Plenio

The reconfigurability of radio environments with programmable metasurfaces is considered a key feature of next-generation wireless networks. Identifying suitable metasurface configurations for desired wireless functionalities requires a…

Signal Processing · Electrical Eng. & Systems 2023-08-07 Jérôme Sol , Hugo Prod'homme , Luc Le Magoarou , Philipp del Hougne

Distributed antennas must be phase-calibrated (phase-synchronized) for certain operations, such as reciprocity-based joint coherent downlink beamforming, to work. We use rigorous signal processing tools to analyze the accuracy of…

Information Theory · Computer Science 2024-01-23 Erik G. Larsson

This paper focuses on assessing the limitations in the direction-finding process of radio sources with directional antennas in an urbanized environment, demonstrating how signal source antenna parameters, such as beamwidth and maximum…

Information Theory · Computer Science 2025-03-25 Cezary Ziolkowski , Jan M. Kelner

Detecting spatial patterns is fundamental to scientific discovery, yet current methods lack statistical consensus and face computational barriers when applied to large-scale spatial omics datasets. We unify major approaches through a single…

Applications · Statistics 2026-02-04 Jiayu Su , Jun Hou Fung , Haoyu Wang , Dian Yang , David A. Knowles , Raul Rabadan

The common approach to inertial sensor calibration for navigation purposes has been to model the stochastic error signals of individual sensors independently, whether as components of a single inertial measurement unit (IMU) in different…

Methodology · Statistics 2019-10-02 Haotian Xu , Stéphane Guerrier , Roberto Molinari , Mucyo Karemera

Several projects in radioastronomy plan to use large static cylindrical reflectors with an extended lobe sampling a sector of the rotating sky. This study provides the exact mathematical expression of the transit time of a celestial object…

Instrumentation and Methods for Astrophysics · Physics 2012-09-03 Marc Moniez