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Related papers: Synthesis imaging with a lunar orbit array: II. Im…

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Very long baseline interferometry (VLBI) technique allows us to determine positions of thousands of radio sources using the absolute astrometry approach. I have investigated the impact of a selection of observing frequencies in a range from…

Instrumentation and Methods for Astrophysics · Physics 2024-05-14 Leonid Petrov

The time-wise and space-wise approaches are generally applied to data processing and error analysis for satellite gravimetry missions. But both the approaches, which are based on least-squares collocation, address the whole effect of…

Geophysics · Physics 2015-06-11 Lin Cai , Zebing Zhou , Houtse Hsu , Fang Gao , Zhu Zhu , Jun Luo

Phase aberration is an inherent side effect of ultrasound imaging due to the speed of sound inhomogeneity nature of human tissues, resulting in focusing error and reduced image contrast. This work introduces a phase aberration correction…

Signal Processing · Electrical Eng. & Systems 2023-08-29 Wei-Hsiang Shen , Yu-An Lin , Pai-Chi Li , Meng-Lin Li

Tilt-to-length (TTL) coupling in the Laser Interferometer Space Antenna (LISA) can generate spurious displacement noise that potentially affects the measurement of gravitational wave signals. In each test mass interferometer, the coupling…

Instrumentation and Methods for Astrophysics · Physics 2025-02-05 Paul Edwards , Megha Dave , Alexander Weaver , Mengyuan Zhao , Paul Fulda , Guido Mueller , Gudrun Wanner

We consider an error model for phased array with gain errors and phase errors, with errors dependent on the phase applied and the antenna index. Under this model, we propose an algorithm for measuring the errors by selectively turning on…

Signal Processing · Electrical Eng. & Systems 2021-07-21 Joyson Sebastian , Pranav Dayal , Kee-Bong Song , Walid AliAhmad

One of the primary sources of suboptimal image quality in ultrasound imaging is phase aberration. It is caused by spatial changes in sound speed over a heterogeneous medium, which disturbs the transmitted waves and prevents coherent…

Image and Video Processing · Electrical Eng. & Systems 2024-07-03 Mostafa Sharifzadeh , Sobhan Goudarzi , An Tang , Habib Benali , Hassan Rivaz

We present a simple and effective method to eliminate system aberrations and speckle noise in quantitative phase imaging. Using spiral integration, complete information about system aberration is calculated from three laterally shifted…

Biological Physics · Physics 2018-02-14 Inhyeok Choi , Kyeoreh Lee , YongKeun Park

This letter presents a dual quadrature phasemeter, an implementation of a phase-locked loop designed to track the phase of homodyne and heterodyne inter-satellite laser links. The dual quadrature phasemeters use dual quadrature optical…

Optics · Physics 2024-10-30 Callum S. Sambridge , Kirk McKenzie

The primary scientific results of the future space-based gravitational wave interferometer LISA will come from the parameter inference of a large variety of gravitational wave sources. However, the presence of calibration errors could…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Etienne Savalle , Jonathan Gair , Lorenzo Speri , Stanislav Babak

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and optical/near-IR bands for mitigating systematic effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Stefano Camera , Ian Harrison , Anna Bonaldi , Michael L. Brown

Purpose: Field monitoring measures field perturbations, which can be accounted for during image reconstructions. In certain field monitoring environments, significant phase deviations can arise far from isocenter due to the finite extent of…

Medical Physics · Physics 2023-01-25 Paul I. Dubovan , Kyle M. Gilbert , Corey A. Baron

Atmospheric water vapor causes significant undesired phase fluctuations for the Submillimeter Array (SMA) interferometer, particularly in its highest frequency observing band of 690 GHz. One proposed solution to this atmospheric effect is…

Astrophysics · Physics 2007-05-23 D. Y. Kubo , T. R. Hunter , R. D. Christensen , P. I. Yamaguchi

Radio interferometer arrays such as HERA consist of many close-packed dishes arranged in a regular pattern, giving rise to a large number of `redundant' baselines with the same length and orientation. Since identical baselines should see an…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-30 Samir Choudhuri , Philip Bull , Hugh Garsden

NASA's return to the Moon presents unparalleled opportunities to advance high-impact scientific capabilities. At the cutting edge of these possibilities are extremely high-resolution interferometric observations at visible and ultraviolet…

In photo injectors, the transverse emittance is one of the key measures of beam quality as it defines the possible performance of the whole facility. As such it is important to measure the emittance in photo injectors and ensure the…

The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large scale and compact emission. It is, however, very challenging to synthesize thermal noise…

We investigate the influence of lunar-like satellites on the infrared orbital light curves of Earth-analog extra-solar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a…

Astrophysics · Physics 2015-05-13 Nicholas A. Moskovitz , Eric Gaidos , Darren Williams

After several generations of interferometers in radioastronomy, wide-field imaging at high angular resolution is today a major goal for trying to match optical wide-field performances. All the radio-interferometric, wide-field imaging…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 Jérôme Pety , Nemesio J. Rodriguez-Fernandez

The impact of formation flying on interferometry is growing over the years for the potential performance it could offer. However, it is still an open field, and many studies are still required. This article presents the basic principles…

Earth and Planetary Astrophysics · Physics 2024-02-22 Cristina Erbeia , Francesca Scala , Camilla Colombo

In current paper, distortions in digital demodulation schemes with harmonic phase modulation for interferometric optical sensors are considered. In particular, the influence of target signal variations on phase demodulation errors is…

Instrumentation and Detectors · Physics 2019-05-08 Leonid Liokumovich , Andrei Medvedev , Konstantin Muravyov , Philipp Skliarov , Nikolai Ushakov