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Related papers: Reduced Ambiguity Calibration for LOFAR

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We introduce SCAR, a method for long-term auto-calibration refinement of aerial visual-inertial systems that exploits georeferenced satellite imagery as a persistent global reference. SCAR estimates both intrinsic and extrinsic parameters…

Computer Vision and Pattern Recognition · Computer Science 2026-02-19 Henry Hölzemann , Michael Schleiss

In view of contemporary panoramic camera-laser scanner system, the traditional calibration method is not suitable for panoramic cameras whose imaging model is extremely nonlinear. The method based on statistical optimization has the…

Computer Vision and Pattern Recognition · Computer Science 2017-09-14 Mingwei Cao , Ming Yang , Chunxiang Wang , Yeqiang Qian , Bing Wang

Ultrasound images formed by delay-and-sum beamforming are plagued by artifacts that only clear up after compounding many transmissions. Some prior works pose imaging as an inverse problem. This approach can yield high image quality with few…

Signal Processing · Electrical Eng. & Systems 2024-07-03 Vincent van de Schaft , Oisín Nolan , Ruud J. G. van Sloun

Interferometric phase linking (IPL) has become a prominent technique for processing images of areas containing distributed scaterrers in SAR interferometry. Traditionally, IPL consists in estimating consistent phase differences between all…

Applications · Statistics 2024-03-14 Phan Viet Hoa Vu , Arnaud Breloy , Frédéric Brigui , Yajing Yan , Guillaume Ginolhac

Interstellar scattering is known to broaden distant objects spatially and temporally. The latter aspect is difficult to analyse, unless the signals carry their own time stamps. Pulsars are so kind to do us this favour. Typically the…

Astrophysics of Galaxies · Physics 2019-04-26 Olaf Wucknitz

We have developed an algorithm that constructs a model of a reconfigurable optical interferometer, independent of specific architectural constraints. The programming of unitary transformations on the interferometer's optical modes relies on…

Quantum Physics · Physics 2025-06-02 Sergei S. Kuzmin , Ivan V. Dyakonov , Stanislav S. Straupe

Precision antenna calibration is required for mitigating the impact of foreground contamination in 21 cm cosmological radio surveys. One widely studied source of error is the effect of missing point sources in the calibration sky model;…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-19 Ntsikelelo Charles , Nicholas Kern , Gianni Bernardi , Landman Bester , Oleg Smirnov , Nicolas Fagnoni , Eloy de Lera Acedo

Context: Exoplanet science has made staggering progress in the last two decades, due to the relentless exploration of new detection methods and refinement of existing ones. Yet astrometry offers a unique and untapped potential of discovery…

One of the principal challenges of 21 cm cosmology experiments is overcoming calibration error. Established calibration approaches in the field require an exquisitely accurate sky model, and low-level sky model errors introduce calibration…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Ruby Byrne

Contactless characterization of mechanical resonances using Fabry-Perot interferometry is a powerful tool to study the mechanical and dynamical properties of atomically thin membranes. However, amplitude calibration is often not performed,…

Mesoscale and Nanoscale Physics · Physics 2018-01-17 Robin J. Dolleman , Dejan Davidovikj , Herre S. J. van der Zant , Peter G. Steeneken

We propose an illumination strategy for interferometric imaging that allows for robust depth recovery from intensity-only measurements. For an array with colocated sources and receivers, we show that all the possible interferometric data…

Optimization and Control · Mathematics 2016-11-30 Miguel Moscoso , Alexei Novikov , George Papanicolaou , Chrysoula Tsogka

A crucial challenge to the scaling up of linear optical interferometers is the presence of defective optical components resulting from inevitable imperfections in fabrication and packaging. This work presents a method for circumventing such…

Quantum Physics · Physics 2019-12-19 Ish Dhand

Speckle interferometry is an established optical metrology tool for the characterization of rough objects. The raw phase, however, is impaired by the presence of phase singularities, making the unwrapping procedure ambiguous. In a Michelson…

Instrumentation and Detectors · Physics 2016-11-11 Klaus Mantel , Vanusch Nercissian

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

Large radio astronomy multi-element interferometers are frequently used as single dishes in a tied-array mode when signals from separate antennas are added. Phase shifts arising during wave propagation through a turbulent atmosphere can…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 P. A. Fridman

Polarimetric imaging has been applied in a growing number of applications in robotic vision (ex. underwater navigation, glare removal, de-hazing, object classification, and depth estimation). One can find on the market RGB Polarization…

Computer Vision and Pattern Recognition · Computer Science 2022-08-30 Joaquin Rodriguez , Lew Lew-Yan-Voon , Renato Martins , Olivier Morel

We reformulate the gain correction problem of the radio interferometry as an optimization problem with regularization, which is solved efficiently with an iterative algorithm. Combining this new method with our previously proposed imaging…

Instrumentation and Methods for Astrophysics · Physics 2024-12-05 Shiro Ikeda , Takeshi Nakazato , Takashi Tsukagoshi , Tsutomu T. Takeuchi , Masayuki Yamaguchi

Accurate extrinsic calibration of multiple LiDARs is crucial for improving the foundational performance of three-dimensional (3D) map reconstruction systems. This paper presents a novel targetless extrinsic calibration framework for…

Robotics · Computer Science 2025-07-15 Han Ye , Yuqiang Jin , Jinyuan Liu , Tao Li , Wen-An Zhang , Minglei Fu

This paper presents a robust fixed lag smoother for a class of nonlinear uncertain systems. A unified scheme, which combines a nonlinear robust estimator with a stable fixed lag smoother, is presented to improve the error covariance of the…

Systems and Control · Computer Science 2013-09-10 Obaid Ur Rehman , Ian R. Petersen

Integrated sensing and communication (ISAC) represents a pivotal advancement for future wireless networks. This paper introduces a novel ISAC beamforming method for enhancing sensing performance while preserving communication quality by…

Information Theory · Computer Science 2025-03-07 Meihui Liu , Shu Sun , Ruifeng Gao , Meixia Tao