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Radio interferometric imaging aims to estimate an unknown sky intensity image from degraded observations, acquired through an antenna array. In the theoretical case of a perfectly calibrated array, it has been shown that solving the…

Instrumentation and Methods for Astrophysics · Physics 2017-07-25 Audrey Repetti , Jasleen Birdi , Arwa Dabbech , Yves Wiaux

Camera calibration involves estimating camera parameters to infer geometric features from captured sequences, which is crucial for computer vision and robotics. However, conventional calibration is laborious and requires dedicated…

Computer Vision and Pattern Recognition · Computer Science 2025-02-25 Kang Liao , Lang Nie , Shujuan Huang , Chunyu Lin , Jing Zhang , Yao Zhao , Moncef Gabbouj , Dacheng Tao

In this chapter we present a brief summary of methods, instruments and calibration techniques used in modern astronomical polarimetry in the optical wavelengths. We describe the properties of various polarization devices and detectors used…

Instrumentation and Methods for Astrophysics · Physics 2019-08-29 Andrei Berdyugin , Vilppu Piirola , Juri Poutanen

General description of an on-line procedure of calibration for IGRT (Image Guided Radiotherapy) is given. The algorithm allows to improve targeting cancer by estimating its position in space and suggests appropriate correction of the…

Medical Physics · Physics 2019-04-02 R. A. Kycia , Z. Tabor , A. Woszczyna , D. Kabat , M. Tulik , Z. Latała

We present a graphical interface designed to demonstrate the techniques of radio interferometry used by telescopes like ALMA, e-Merlin, the JVLA and SKA, in a manner accessible to the general public. Interferometry is an observational tech-…

Instrumentation and Methods for Astrophysics · Physics 2012-11-02 Adam Avison , Samuel J George

Compact interferometers, called phasemeters, make it possible to operate over a large range while ensuring a high resolution. Such performance is required for the stabilization of large instruments dedicated to experimental physics such as…

Instrumentation and Methods for Astrophysics · Physics 2018-12-03 Jennifer Watchi , Sam Cooper , Binlei Ding , Conor M. Mow-Lowry , Christophe Collette

Interest in pupil-remapping interferometry, in which a single telescope pupil is fragmented and recombined using fiber optic technologies, has been growing among a number of groups. As a logical extrapolation from several highly successful…

Radiometry has been of fundamental importance in astronomy from the early beginnings. In this review, we provide an overview of how to achieve a valid laboratory calibration of space telescopes and discuss ways to reliably extend this…

Instrumentation and Methods for Astrophysics · Physics 2016-01-12 Anuschka Pauluhn , Martin C. E. Huber , Peter L. Smith , Luis Colina

One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two…

The number of publications of aperture-synthesis images based on optical long-baseline interferometry measurements has recently increased due to easier access to visible and infrared interferometers. The interferometry technique has now…

One of the biggest challenges in operating massive multiple-input multiple-output systems is the acquisition of accurate channel state information at the transmitter. To take up this challenge, time division duplex is more favorable thanks…

Information Theory · Computer Science 2024-10-30 Xiwen Jiang , Alexis Decurninge , Kalyana Gopala , Florian Kaltenberger , Maxime Guillaud , Dirk Slock , Luc Deneire

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

Context: Radio interferometers measure frequency components of the sky brightness, modulated by the gains of the individual radio antennas. Due to atmospheric turbulence and variations in the operational conditions of the antennas these…

Instrumentation and Methods for Astrophysics · Physics 2023-10-25 Jakob Roth , Philipp Arras , Martin Reinecke , Richard A. Perley , Rüdiger Westermann , Torsten A. Enßlin

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

Calibration is a common practice in image steganalysis for extracting prominent features. Based on the idea of reembedding, a new set of calibrated features for audio steganalysis applications are proposed. These features are extracted from…

Multimedia · Computer Science 2018-08-31 Hamzeh Ghasemzadeh , Mohammad H. Kayvanrad

Programmable linear optical interferometers are important for classical and quantum information technologies, as well as for building hardware-accelerated artificial neural networks. Recent results showed the possibility of constructing…

Recent developments in optimization theory have extended some traditional algorithms for least-squares optimization of real-valued functions (Gauss-Newton, Levenberg-Marquardt, etc.) into the domain of complex functions of a complex…

Instrumentation and Methods for Astrophysics · Physics 2015-02-27 Oleg Smirnov , Cyril Tasse

A new method for absolute polarimetric calibration of large telescopes is presented. The proposed method is highly accurate and is based on the calibration of a small sub-aperture, which is then extended to the full system by means of…

Astrophysics · Physics 2009-11-10 H. Socas-Navarro

The technique of non-redundant masking (NRM) transforms a conventional telescope into an interferometric array. In practice, this provides a much better constrained point spread function than a filled aperture and thus higher resolution…

Instrumentation and Methods for Astrophysics · Physics 2017-11-29 Steph Sallum , Josh Eisner

We describe a "spatio-spectral" deconvolution algorithm for wide-band imaging in radio interferometry. In contrast with the existing multi-frequency reconstruction algorithms, the proposed method does not rely on a model of the…

Instrumentation and Methods for Astrophysics · Physics 2016-03-01 André Ferrari , Jérémy Deguignet , Chiara Ferrari , David Mary , Antony Schutz , Oleg Smirnov