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The measurement of shape parameters of sources in astronomical images is usually performed by assuming that the underlying noise is uncorrelated. Spatial noise correlation is however present in practice due to various observational effects…

Astrophysics · Physics 2007-05-23 A. Refregier , S. T. Brown

Instrumental variable (IV) methods are used to estimate causal effects in settings with unobserved confounding, where we cannot directly experiment on the treatment variable. Instruments are variables which only affect the outcome…

Methodology · Statistics 2023-05-26 Elisabeth Ailer , Jason Hartford , Niki Kilbertus

We present a statistical analysis of a variant of the periodogram method that forms power spectral density estimates by cross-correlating the discrete Fourier transforms of adjacent time windows. The proposed estimator is closely related to…

Statistics Theory · Mathematics 2026-03-24 Mark Magsino

The VST Optical Imaging of the CDFS and ES1 Fields (VOICE) Survey is proposed to obtain deep optical $ugri$ imaging of the CDFS and ES1 fields using the VLT Survey Telescope (VST). At present, the observations for the CDFS field have been…

The knowledge of receiver beam shapes is essential for accurate radio interferometric imaging. Traditionally, this information is obtained by holographic techniques or by numerical simulation. However, such methods are not feasible for an…

Instrumentation and Methods for Astrophysics · Physics 2013-07-19 Sarod Yatawatta

The periodicity inherent to any interferometric signal entails a fundamental trade-off between sensitivity and dynamic range of interferometry-based sensors. Here we develop a methodology for significantly extending the dynamic range of…

Atomic Physics · Physics 2020-11-06 Dimitry Yankelev , Chen Avinadav , Nir Davidson , Ofer Firstenberg

We present computer simulations of interferometric imaging with the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO) and the Astronomical MultiBEam Recombiner (AMBER) phase-closure instrument. These…

Astrophysics · Physics 2015-06-24 F. Przygodda , T. Bloecker , K. -H. Hofmann , G. Weigelt

We present $\mathcal{O}(N^2)$ estimators for the small-scale power spectrum and bispectrum in cosmological simulations. In combination with traditional methods, these allow spectra to be efficiently computed across a vast range of scales,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-21 Oliver H. E. Philcox

The single-scatter approximation is fundamental in many tomographic imaging problems including x-ray scatter imaging and optical scatter imaging for certain media. In all cases, noisy measurements are affected by both local scatter events…

Image and Video Processing · Electrical Eng. & Systems 2021-04-21 Michael R. Walker , Joseph A. O'Sullivan

Our ability to calibrate current kilometer-scale interferometers can potentially confound the inference of astrophysical signals. Current calibration uncertainties are well described by a Gaussian process. I exploit this description to…

Instrumentation and Methods for Astrophysics · Physics 2022-04-27 Reed Essick

The Cosmic Radio Dipole is of fundamental interest to cosmology. Recent studies revealed open questions about the nature of the observed Cosmic Radio Dipole. We use simulated source count maps to test a linear and a quadratic estimator for…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-07 Thilo M. Siewert , Matthias Schmidt-Rubart , Dominik J. Schwarz

Shrinkage estimation usually reduces variance at the cost of bias. But when we care only about some parameters of a model, I show that we can reduce variance without incurring bias if we have additional information about the distribution of…

Statistics Theory · Mathematics 2017-11-01 Jann Spiess

Next-generation gravitational wave detectors such as the Einstein Telescope and Cosmic Explorer will have increased sensitivity and observing volumes, enabling unprecedented precision in parameter estimation. However, this enhanced…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Veome Kapil , Luca Reali , Roberto Cotesta , Emanuele Berti

The method of instrumental variables (IV) provides a framework to study causal effects in both randomized experiments with noncompliance and in observational studies where natural circumstances produce as-if random nudges to accept…

Methodology · Statistics 2018-02-07 Hyunseung Kang , Laura Peck , Luke Keele

A popular technique for selecting and tuning machine learning estimators is cross-validation. Cross-validation evaluates overall model fit, usually in terms of predictive accuracy. In causal inference, the optimal choice of estimator…

Methodology · Statistics 2021-07-07 Dominik Rothenhäusler

We apply the Fourier Power Function Shapelets (FPFS) shear estimator to the first year data of the Hyper Suprime-Cam survey to construct a shape catalog. The FPFS shear estimator has been demonstrated to have multiplicative bias less than…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-19 Xiangchong Li , Masamune Oguri , Nobuhiko Katayama , Wentao Luo , Wenting Wang , Jiaxin Han , Hironao Miyatake , Keigo Nakamura , Surhud More

We present computer simulations of interferometric imaging with the VLT interferometer and the AMBER instrument. These simulations include both the astrophysical modelling of a stellar object by radiative transfer calculations and the…

Astrophysics · Physics 2015-06-24 T. Bloecker , K. -H. Hofmann , F. Przygodda , G. Weigelt

High-accuracy dimensional measurements by laser interferometers require corrections because of diffraction, which makes the effective fringe-period different from the wavelength of a plane (or spherical) wave $\lambda_0$. By using a…

Optics · Physics 2016-04-20 Carlo Paolo Sasso , Enrico Massa , Giovanni Mana

When measuring the roughness of rough surfaces, the limited sizes of scanned areas lead to its systematic underestimation. Levelling by polynomials and other filtering used in real-world processing of atomic force microscopy data increases…

Data Analysis, Statistics and Probability · Physics 2020-04-28 David Nečas , Petr Klapetek , Miroslav Valtr

Many deep wide-band wide-field radio interferometric surveys are being designed to accurately measure intensities, spectral indices and polarization properties of faint source populations. In this paper we compare various wideband imaging…

Instrumentation and Methods for Astrophysics · Physics 2016-10-26 Urvashi Rau , Sanjay Bhatnagar , Frazer N. Owen