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Wide-field images made by radio interferometers are invariably affected by direction-dependent systematic effects such as the ionosphere or the beam pattern. Calibration along a set of discrete directions in the sky is the default technique…

Instrumentation and Methods for Astrophysics · Physics 2026-02-06 Sebastiaan van der Tol , Sarod Yatawatta , Bram Veenboer , David Rafferty

We demonstrate how the image analysis technique of wavelet decomposition can be applied to the gamma-ray sky to separate emission on different angular scales. New structures on scales that differ from the scales of the conventional…

High Energy Astrophysical Phenomena · Physics 2016-08-03 Samuel D. McDermott , Patrick J. Fox , Ilias Cholis , Samuel K. Lee

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

In order to produce high dynamic range images in radio interferometry, bright extended sources need to be removed with minimal error. However, this is not a trivial task because the Fourier plane is sampled only at a finite number of…

Instrumentation and Methods for Astrophysics · Physics 2011-01-17 Sarod Yatawatta

The next generation of radio surveys is going to be transformative for cosmology and other aspects of our understanding of astrophysics. Realistic simulations of radio observations are essential for the design and planning of radio surveys.…

Instrumentation and Methods for Astrophysics · Physics 2025-07-30 Tobias Vičánek Martínez , Henrik W. Edler , Marcus Brüggen

With increasing amounts of data in astronomy, automated analysis methods have become crucial. Synthetic data are required for developing and testing such methods. Current simulations often suffer from insufficient detail or inaccurate…

Instrumentation and Methods for Astrophysics · Physics 2024-11-27 Tobias Vičánek Martínez , Nicolás Barón Pérez , Marcus Brüggen

We present a new approach to measure the shapes of galaxies, a fundamental task in observational astronomy. This approach is based on the decomposition of a galaxy image into a series of orthogonal basis functions, or `shapelets'. Our…

Astrophysics · Physics 2017-08-23 Alexandre Refregier , Tzu-Ching Chang , David Bacon

We present a new method for the analysis of images, a fundamental task in observational astronomy. It is based on the linear decomposition of each object in the image into a series of localised basis functions of different shapes, which we…

Astrophysics · Physics 2008-11-26 Alexandre Refregier

The new generation of radio interferometers is characterized by high sensitivity, wide fields of view and large fractional bandwidth. To synthesize the deepest images enabled by the high dynamic range of these instruments requires us to…

Instrumentation and Methods for Astrophysics · Physics 2018-04-25 C. Tasse , B. Hugo , M. Mirmont , O. Smirnov , M. Atemkeng , L. Bester , M. J. Hardcastle , R. Lakhoo , S. Perkins , T. Shimwell

Radio interferometry enables high-resolution imaging of astronomical radio sources by synthesizing a large effective aperture from an array of antennas and solving a deconvolution problem to reconstruct the image. Deep learning has emerged…

Instrumentation and Methods for Astrophysics · Physics 2026-03-11 Zihui Wu , Liam Connor , Samuel McCarty , Katherine L. Bouman

Modern radio interferometers deliver large volumes of data containing high-sensitivity sky maps over wide fields-of-view. These large area observations can contain various and superposed structures such as point sources, extended objects,…

Instrumentation and Methods for Astrophysics · Physics 2025-12-05 Richard Fuchs , Jakob Knollmüller , Jakob Roth , Vincent Eberle , Philipp Frank , Torsten A. Enßlin , Lukas Heinrich

Radio interferometric data are used to estimate the sky brightness distributions in radio frequencies. Here we focus on estimators of the large-scale structure and the power spectrum of the sky brightness distribution inferred from radio…

Instrumentation and Methods for Astrophysics · Physics 2019-04-17 Prasun Dutta , Meera Nandakumar

We present a method to simulate deep sky images, including realistic galaxy morphologies and telescope characteristics. To achieve a wide diversity of simulated galaxy morphologies, we first use the shapelets formalism to parametrize the…

Deep Learning (DL) has shown remarkable results in solving inverse problems in various domains. In particular, the Tikhonet approach is very powerful to deconvolve optical astronomical images (Sureau et al. 2020). Yet, this approach only…

Instrumentation and Methods for Astrophysics · Physics 2022-07-20 F. Nammour , U. Akhaury , J. N. Girard , F. Lanusse , F. Sureau , C. Ben Ali , J. -L. Starck

We present a filtering technique that can be applied to individual baselines of wide-bandwidth, wide-field interferometric data to geometrically select regions on the celestial sphere that contain primary calibration sources. The technique…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Aaron R. Parsons , Donald C. Backer

Vision Transformers are used via a customized TransUNet architecture, which is a hybrid model combining Transformers into a U-Net backbone, to achieve precise, automated, and fast segmentation of radio astronomy data affected by calibration…

Instrumentation and Methods for Astrophysics · Physics 2025-08-14 Nicoletta Sanvitale , Claudio Gheller , Franco Vazza , Annalisa Bonafede , Virginia Cuciti , Emanuele De Rubeis , Federica Govoni , Matteo Murgia , Valentina Vacca

We describe a scalable distributed imaging algorithm framework for next-generation radio telescopes, managing the Fourier transform from apertures to sky (or vice versa) with a focus on minimising memory load, data transfers, and…

Instrumentation and Methods for Astrophysics · Physics 2024-07-17 Peter Wortmann , James Kent , Bojan Nikolic

Diffusion models are powerful tools for sampling from high-dimensional distributions by progressively transforming pure noise into structured data through a denoising process. When equipped with a guidance mechanism, these models can also…

Machine Learning · Computer Science 2026-05-04 Saeed Mohseni-Sehdeh , Walid Saad , Kei Sakaguchi , Tao Yu

Diffusion models have demonstrated exceptional performance across various domains due to their ability to model and generate complicated data distributions. However, when applied to PolSAR data, traditional real-valued diffusion models face…

Computer Vision and Pattern Recognition · Computer Science 2025-07-09 Junfei Shi , Yu Cheng , Haiyan Jin , Junhuai Li , Zhaolin Xiao , Maoguo Gong , Weisi Lin

Unbiased sky background modeling is crucial for the analysis of deep wide-field images, but it remains a major challenge in low surface brightness astronomy. Traditional image processing algorithms are often designed to produce artificially…

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