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Related papers: Imaging algorithms in radio interferometry

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We present a new calibration scheme based on a non-linear version of Kalman filter that aims at estimating the physical terms appearing in the Radio Interferometry Measurement Equation (RIME). We enrich the filter's structure with a tunable…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Cyril Tasse

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

Optical microscopy is an indispensable tool in life sciences research, but conventional techniques require compromises between imaging parameters like speed, resolution, field-of-view, and phototoxicity. To overcome these limitations,…

Quantitative Methods · Quantitative Biology 2024-04-01 Leonor Morgado , Estibaliz Gómez-de-Mariscal , Hannah S. Heil , Ricardo Henriques

In the past two decades, a rebirth of interest in low-frequency radio astronomy for 21 cm tomography of the Epoch of Reionization, has given rise to a new class of radio interferometers with $N \gg 100$ antennas. The availability of…

Instrumentation and Methods for Astrophysics · Physics 2022-08-11 Deepthi Gorthi

Fourier ptychographic microscopy is a computational imaging technique that provides quantitative phase information and high resolution over a large field-of-view. Although the technique presents numerous advantages over conventional…

Optics · Physics 2021-09-16 Eric Li , Stuart Sherwin , Gautam Gunjala , Laura Waller

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

The iterative refinement method (IRM) has been very successfully applied in many different fields for examples the modern quantum chemical calculation and CT image reconstruction. It is proved that the refinement method can create an exact…

Medical Physics · Physics 2015-12-23 Kang Yang , Kevin Yang , Xintie Yang , Shuang-Ren Zhao

Redundant calibration is a technique in radio astronomy that allows calibration of radio arrays whose antennas lie on a lattice by exploiting the fact that redundant baselines should see the same sky signal. Because the number of measured…

Instrumentation and Methods for Astrophysics · Physics 2022-08-17 Prakruth Adari , Anže Slosar

During the last two decades, the first generation of beam combiners at the Very Large Telescope Interferometer has proved the importance of optical interferometry for high-angular resolution astrophysical studies in the near- and…

The calibration of modern radio interferometers is a significant challenge, specifically at low frequencies. In this perspective, we propose a novel iterative calibration algorithm, which employs the popular sparse representation framework,…

Instrumentation and Methods for Astrophysics · Physics 2016-06-06 Martin Brossard , Mohamed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal

The emerging generation of radio interferometric (RI) telescopes, such as the Square Kilometre Array (SKA), will acquire massive volumes of data and transition radio astronomy to a big-data era. The ill-posed inverse problem of imaging the…

Instrumentation and Methods for Astrophysics · Physics 2019-04-04 Xiaohao Cai , Luke Pratley , Jason D. McEwen

The noise in absorption imaging of cold atoms significantly impacts measurement accuracy across a range of applications with ultracold atoms. It is crucial to adopt an approach that offers effective denoising capabilities without…

Interferometry has brought many new constraints in optical astronomy in the recent years. A major leap in this field is the opening of large interferometric facilities like the Very Large Telescope Interferometer and the Keck Interferometer…

Astrophysics · Physics 2007-05-23 F. Malbet

Optical projection tomography (OPT) is a powerful tool for biomedical studies. It achieves 3D visualization of mesoscopic biological samples with high spatial resolution using conventional tomographic-reconstruction algorithms. However,…

Computer Vision and Pattern Recognition · Computer Science 2023-10-02 Yan Liu , Jonathan Dong , Thanh-An Pham , Francois Marelli , Michael Unser

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

Atom interferometers are sensitive to a wide range of forces by encoding their signals in interference patterns of matter waves. To estimate the magnitude of these forces, the underlying phase shifts they imprint on the atoms must be…

In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a…

Images acquired by computer vision systems under low light conditions have multiple characteristics like high noise, lousy illumination, reflectance, and bad contrast, which make object detection tasks difficult. Much work has been done to…

Computer Vision and Pattern Recognition · Computer Science 2021-08-02 Winston Chen , Tejas Shah

This paper introduces an astronomical image alignment algorithm. This algorithm uses the means of the rows and columns of the original image for alignment, and finds the optimal offset corresponding to the maximum similarity by comparing…

Instrumentation and Methods for Astrophysics · Physics 2024-04-16 Jie Zheng , Linqiao Jiang , Jianfeng Tian

Radio interferometric gain calibration can be biased by incomplete sky models and radio frequency interference, resulting in calibration artefacts that can restrict the dynamic range of the resulting images. It has been suggested that…

Instrumentation and Methods for Astrophysics · Physics 2019-10-21 Ulrich Armel Mbou Sob , Hertzog Landman Bester , Oleg Smirnov , Jonathan Kenyon , Trienko Grobler
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