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Related papers: Reduced Ambiguity Calibration for LOFAR

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Recent work has successfully achieved sub-arcsecond wide-field imaging with high-band observations from the Low Frequency Array (LOFAR). However, the scalability of this work remains limited due to the need for manual intervention, poor…

Cameras and LiDAR are essential sensors for autonomous vehicles. The fusion of camera and LiDAR data addresses the limitations of individual sensors but relies on precise extrinsic calibration. Recently, numerous end-to-end calibration…

Computer Vision and Pattern Recognition · Computer Science 2025-07-08 Ni Ou , Zhuo Chen , Xinru Zhang , Junzheng Wang

Radio Interferometry is an essential method for astronomical observations. Self-calibration techniques have increased the quality of the radio astronomical observations (and hence the science) by orders of magnitude. Recently, there is a…

Astrophysics · Physics 2008-11-03 Sarod Yatawatta , Saleem Zaroubi , Ger de Bruyn , Leon Koopmans , Jan Noordam

Calibration of radio interferometric observations becomes increasingly difficult towards lower frequencies. Below ~300 MHz, spatially variant refractions and propagation delays of radio waves traveling through the ionosphere cause phase…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 H. T. Intema , S. van der Tol , W. D. Cotton , A. S. Cohen , I. M. van Bemmel , H. J. A. Rottgering

In order to meet the theoretically achievable imaging performance, calibration of modern radio interferometers is a mandatory challenge, especially at low frequencies. In this perspective, we propose a novel parallel iterative…

Instrumentation and Methods for Astrophysics · Physics 2016-09-09 Martin Brossard , Mohammed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal , Stefan J. Wijnholds

Current traditional methods for LiDAR-camera extrinsics estimation depend on offline targets and human efforts, while learning-based approaches resort to iterative refinement for calibration results, posing constraints on their…

Computer Vision and Pattern Recognition · Computer Science 2023-12-05 Shuang Xu , Sifan Zhou , Zhi Tian , Jizhou Ma , Qiong Nie , Xiangxiang Chu

With ever increasing data rates produced by modern radio telescopes like LOFAR and future telescopes like the SKA, many data processing steps are overwhelmed by the amount of data that needs to be handled using limited compute resources.…

Instrumentation and Methods for Astrophysics · Physics 2020-03-18 Sarod Yatawatta

The development of sensitive large format imaging arrays for the infrared promises to provide revolutionary capabilities for space astronomy. For example, the Infrared Array Camera (IRAC) on SIRTF will use four 256 x 256 arrays to provide…

Astrophysics · Physics 2016-08-30 D. J. Fixsen , S. H. Moseley , R. G. Arendt

The response of the Advanced LIGO interferometers is known to vary with time [arXiv:1608.05134]. Accurate calibration of the interferometers must therefore track and compensate for temporal variations in calibration model parameters. These…

Instrumentation and Methods for Astrophysics · Physics 2023-01-11 Madeline Wade , Aaron D. Viets , Theresa Chmiel , Madeline Stover , Leslie Wade

Calibration is an essential step in radio interferometric data processing that corrects the data for systematic errors and in addition, subtracts bright foreground interference to reveal weak signals hidden in the residual. These weak and…

Instrumentation and Methods for Astrophysics · Physics 2019-05-08 Sarod Yatawatta

We study the impact of sky-based calibration errors from source mismodeling on 21\,cm power spectrum measurements with an interferometer and propose a method for suppressing their effects. While emission from faint sources that are not…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 Aaron Ewall-Wice , Joshua S. Dillon , Adrian Liu , Jacqueline Hewitt

Time of flight based Non-line-of-sight (NLOS) imaging approaches require precise calibration of illumination and detector positions on the visible scene to produce reasonable results. If this calibration error is sufficiently high,…

Image and Video Processing · Electrical Eng. & Systems 2021-05-25 Subhash Chandra Sadhu , Abhishek Singh , Tomohiro Maeda , Tristan Swedish , Ryan Kim , Lagnojita Sinha , Ramesh Raskar

Cameras and LiDAR are essential sensors for autonomous vehicles. Camera-LiDAR data fusion compensate for deficiencies of stand-alone sensors but relies on precise extrinsic calibration. Many learning-based calibration methods predict…

Computer Vision and Pattern Recognition · Computer Science 2025-07-08 Ni Ou , Zhuo Chen , Xinru Zhang , Junzheng Wang

This study is concerned with the design of a Mueller imaging polarimeter for the visualization of spatially-varying Mueller matrix fields. A simplified calibration procedure is advocated, where all the optical elements are calibrated…

Instrumentation and Detectors · Physics 2018-11-08 Yvain Quéau , Florian Leporcq , Ayman Alfalou

High precison calibration is essential for a new generation of radio interferometers looking for Epoch of Reionization and Baryon Acoustic Oscillation signatures in neutral hydrogen. These arrays have so far been calibrated by redundant…

Instrumentation and Methods for Astrophysics · Physics 2017-01-10 J. L. Sievers

The knowledge of receiver beam shapes is essential for accurate radio interferometric imaging. Traditionally, this information is obtained by holographic techniques or by numerical simulation. However, such methods are not feasible for an…

Instrumentation and Methods for Astrophysics · Physics 2013-07-19 Sarod Yatawatta

We combine single- and two-photon interference procedures for characterizing any multi-port linear optical interferometer accurately and precisely. Accuracy is achieved by estimating and correcting systematic errors that arise due to…

Quantum Physics · Physics 2016-03-03 Ish Dhand , Abdullah Khalid , He Lu , Barry C. Sanders

The LOw-Frequency ARray (LOFAR) is used to make precise measurements of radio emission from extensive air showers, yielding information about the primary cosmic ray. Interpreting the measured data requires an absolute and…

Multiple lidars are prevalently used on mobile vehicles for rendering a broad view to enhance the performance of localization and perception systems. However, precise calibration of multiple lidars is challenging since the feature…

Computer Vision and Pattern Recognition · Computer Science 2019-04-30 Jianhao Jiao , Qinghai Liao , Yilong Zhu , Tianyu Liu , Yang Yu , Rui Fan , Lujia Wang , Ming Liu

The first astrophysical results of the VLTI focal instrument AMBER have shown the importance of the differential and closure phase measures, which are supposed to be much less sensitive to atmospheric and instrumental biases than the…

Astrophysics · Physics 2009-11-13 Florentin Millour , Romain Petrov , Martin Vannier , Stefan Kraus