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Optical interferometers increasingly use single-mode fibers as spatial filters to convert varying wavefront distortion into intensity fluctuations which can be monitored for accurate calibration of fringe amplitudes. Here I propose using an…

Astrophysics · Physics 2009-11-06 J. D. Monnier

Interferometric scattering microscopy is a powerful technique that enables various applications, such as mass photometry and particle tracking. Here we present a numerical toolbox to simulate images obtained in interferometric scattering,…

Ultrafast pulse optical vortices are spatiotemporal structures with a diverse range of applications. There are different ways to generate them, often restricted to a wavelength range. Likewise, characterization techniques frequently possess…

Optics · Physics 2025-04-01 Miguel López-Ripa , Íñigo Sola , Benjamín Alonso

Integrated optics are used to achieve astronomical interferometry inside robust and compact materials, improving the instruments stability and sensitivity. In order to perform differential phase measurements at the H$\alpha$ line (656.3 nm)…

Aperture synthesis radio telescopes generate images of celestial bodies from data obtained from several radio antennas. Placement of these antennas has always been a source of interesting problems. Often, several potentially contradictory…

Instrumentation and Methods for Astrophysics · Physics 2009-02-02 M. V. Panduranga Rao , Amrit Lal Ahuja , Srinivasan Iyengar , Sachin Lodha , Kavita Iyer , Ranu Khade , Dinesh Mehta , Balasz Nagy

Spectroscopic measurements can show distorted spectral shapes arising from a mixture of absorbing and scattering contributions. These distortions (or baselines) often manifest themselves as non-constant offsets or low-frequency…

Machine Learning · Statistics 2024-02-27 Erik Andries , Ramin Nikzad-Langerodi

Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced hundreds of meters apart. To obtain rich direct images, many apertures will be needed, for a better sampling of the incoming wavefront.…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha , Antoine Labeyrie

Generating images from very long baseline interferometric observations poses a difficult, and generally not unique, inversion problem. This problem is simplified by the introduction of constraints, some generic (e.g., positivity of the…

Instrumentation and Methods for Astrophysics · Physics 2022-08-22 Avery E. Broderick , Dominic W. Pesce , Paul Tiede , Hung-Yi Pu , Roman Gold

Emittance measurements using synchrotron radiation are usually performed using x-rays to avoid diffraction limits. Interferometric techniques using visible light are also used to measure either the horizontal or the vertical beam…

Accelerator Physics · Physics 2025-01-09 Ubaldo Iriso , Laura Torino , Chris Carilli , Bojan Nikolic , Nithyanandan Thyagarajan

Aperture synthesis observations with full polarisation have long been used to study the magnetic fields of synchrotron emitting sources. Recently proposed closure invariants give us a powerful method for extracting information from measured…

Instrumentation and Methods for Astrophysics · Physics 2024-07-02 Vinay Kumar , Rajaram Nityananda , Joseph Samuel

Energy consumption and hardware cost of signal digitization together with the management of the resulting data volume form serious issues for high-rate measurement systems with multiple sensors. Switching to binary sensing front-ends…

Instrumentation and Methods for Astrophysics · Physics 2019-07-16 Manuel S. Stein

The current status of the high spatial resolution imaging interferometry in optical astronomy is reviewed in the light of theoretical explanation, as well as of experimental constraints that exist in the present day technology. The basic…

Astrophysics · Physics 2007-05-23 S. K. Saha

The following exercises aim to learn the link between the object intensity distribution and the corresponding visibility curves of a long-baseline ptical interferometer. They are also intended to show the additional constraints on…

Traditional phase-shifting interferometry technique cannot be used to measure time-varying phase distributions. But single shot techniques could resolve the problem. Many efforts have been made on the phase retrieval methods from a single…

Instrumentation and Detectors · Physics 2020-03-31 Lifa Hu , Wen Shena , Wenchao Ma , Dongting Hu , Xinyu Liu

Interferometric Synthetic Aperture Radar (InSAR) Imaging methods are usually based on algorithms of match-filtering type, without considering the scene's characteristic, which causes limited imaging quality. Besides, post-processing steps…

Signal Processing · Electrical Eng. & Systems 2022-10-07 Xu Zhan , Xiaoling Zhang , Shunjun Wei , Jun Shi

Many undergraduate radio astronomy courses are unable to give a detailed treatment of aperture synthesis due to time constraints and limited math backgrounds of students. We have taken a laboratory-based approach to teaching radio…

Instrumentation and Methods for Astrophysics · Physics 2019-02-13 J. M. Marr , A. E. E. Rogers , V. L. Fish , F. P. Wilkin , M. B. Arndt , G. Holodak , K. Durkota

For future mmWave mobile communication systems the use of analog/hybrid beamforming is envisioned be a key as- pect. The synthesis of beams is a key technology of enable the best possible operation during beamsearch, data transmission and…

Information Theory · Computer Science 2017-04-27 Kilian Roth , Josef A. Nossek

In the problem of spotlight mode airborne synthetic aperture radar (SAR) image formation, it is well-known that data collected over a wide azimuthal angle violate the isotropic scattering property typically assumed. Many techniques have…

Image and Video Processing · Electrical Eng. & Systems 2023-04-12 Victor Churchill , Anne Gelb

A mid-infrared nulling-space interferometer is a promising way to characterize thermal light from habitable planet candidates around Sun-like stars. However, one of the main challenges for achieving this ambitious goal is a high-precision…

Instrumentation and Methods for Astrophysics · Physics 2023-08-04 Taro Matsuo , Felix Dannert , Romain Laugier , Sascha P. Quanz , Andjelka B. Kovacevic , LIFE collaboration

This paper develops a unifying framework for signal reconstruction from interferometric measurements that is broadly applicable to various applications of interferometry. In this framework, the problem of signal reconstruction in…

Information Theory · Computer Science 2017-07-03 Davood Mardani , George K. Atia , Ayman F. Abouraddy