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In Fourier ptychography, multiple low resolution images are captured and subsequently combined computationally into a high-resolution, large-field of view micrograph. A theoretical image-formation model based on the assumption of plane-wave…

Optics · Physics 2022-06-22 Tomas Aidukas , Lars Loetgering , Andrew Robert Harvey

Interferometric imaging is an emerging technique for particle tracking and mass photometry. Mass or position are estimated from weak signals, coherently scattered from nanoparticles or single molecules, and interfered with a co-propagating…

Numerical inversion is a general detector calibration technique that is independent of the underlying spectrum. This procedure is formalized and important statistical properties are presented, using high energy jets at the Large Hadron…

Data Analysis, Statistics and Probability · Physics 2017-04-18 Aviv Cukierman , Benjamin Nachman

A distortion calibration method for wide-angle lens is proposed based on fringe-pattern phase analysis. Firstly, according to the experimental result of the radial distortion of the image not related to the recording depth of field, but…

Image and Video Processing · Electrical Eng. & Systems 2019-11-28 Weishuai Zhou , Jiawen Weng , Junzheng Peng , Jingang Zhong

We propose a solution to the problem of astrometric and photometric calibration of coronagraphic images with a simple optical device which, in theory, is easy to use. Our design uses the Fraunhofer approximation of Fourier optics. Placing a…

Astrophysics · Physics 2008-11-26 Anand Sivaramakrishnan , Ben R. Oppenheimer

The demand for multimodal sensing systems for robotics is growing due to the increase in robustness, reliability and accuracy offered by these systems. These systems also need to be spatially and temporally co-registered to be effective. In…

Robotics · Computer Science 2020-01-20 Chanoh Park , Peyman Moghadam , Soohwan Kim , Sridha Sridharan , Clinton Fookes

A simple, yet general, formalism for the optimized linear combination of astrophysical images is constructed and demonstrated. The formalism allows the user to combine multiple undersampled images to provide oversampled output at high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Barnaby Rowe , Christopher Hirata , Jason Rhodes

Wide field-of-view (FOV) cameras, which capture a larger scene area than narrow FOV cameras, are used in many applications including 3D reconstruction, autonomous driving, and video surveillance. However, wide-angle images contain…

Computer Vision and Pattern Recognition · Computer Science 2021-12-02 Jinlong Fan , Jing Zhang , Stephen J. Maybank , Dacheng Tao

High fidelity radio interferometric data calibration that minimises spurious spectral structure in the calibrated data is essential in astrophysical applications, such as 21 cm cosmology, which rely on knowledge of the relative spectral…

Instrumentation and Methods for Astrophysics · Physics 2022-10-26 Peter H. Sims , Jonathan C. Pober , Jonathan L. Sievers

New generation of radio interferometers are envisaged to produce high quality, high dynamic range Stokes images of the observed sky from the corresponding under-sampled Fourier domain measurements. In practice, these measurements are…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Jasleen Birdi , Audrey Repetti , Yves Wiaux

The detection and characterisation of extra-solar planets is a major theme driving modern astronomy, with the vast majority of such measurements being achieved by Doppler radial-velocity and transit observations. Another technique -- direct…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Barnaby Norris , Nick Cvetojevic , Simon Gross , Nemanja Jovanovic , Paul N. Stewart , Ned Charles , Jon S. Lawrence , Michael J. Withford , Peter Tuthill

Reconstruction of the sky brightness measured by radio interferometers is typically achieved through gridding techniques, or histograms in spatial Fourier space. For Epoch of Reionisation (EoR) 21 cm power spectrum measurements, extreme…

Instrumentation and Methods for Astrophysics · Physics 2022-04-22 Nichole Barry , Aman Chokshi

Image reconstruction in very-long baseline interferometry operates under severely sparse aperture coverage with calibration challenges from both the participating instruments and propagation medium, which introduce the risk of biases and…

Instrumentation and Methods for Astrophysics · Physics 2026-01-14 Samuel Lai , Nithyanandan Thyagarajan , O. Ivy Wong , Foivos Diakogiannis

The turbulent ionosphere causes phase shifts to incoming radio waves on a broad range of temporal and spatial scales. When an interferometer is not sufficiently calibrated for the direction-dependent ionospheric effects, the time-varying…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-02 S. A. Brackenhoff , M. Mevius , L. V. E. Koopmans , A. Offringa , E. Ceccotti , J. K. Chege , B. K. Gehlot , S. Ghosh , C. Höfer , F. G. Mertens , S. Munshi , S. Zaroubi

The light field camera is useful for computer graphics and vision applications. Calibration is an essential step for these applications. After calibration, we can rectify the captured image by using the calibrated camera parameters.…

Computer Vision and Pattern Recognition · Computer Science 2014-07-17 Yichao Xu , Kazuki Maeno , Hajime Nagahara , Rin-ichiro Taniguchi

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

We present a new algorithm to perform wide-field radio interferometric image reconstruction, with exact non-coplanar correction, that scales to big-data. This algorithm allows us to image 2 billion visibilities on 50 nodes of a computing…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 Luke Pratley , Jason D. McEwen

Measured impulse responses obtained from a dynamic unmanned aerial vehicle (UAV) channel sounding system exhibit effects attributable to time-varying carrier frequency offset (CFO) and sampling frequency offset (SFO). To correct the…

Signal Processing · Electrical Eng. & Systems 2025-12-17 Lorenz Mohr , Marc Miranda , Sebastian Semper , Julia Beuster , Carsten Andrich , Sebastian Giehl , Christian Schneider , Reiner S. Thomä

The recent years have given rise to a large number of techniques for "looking around corners", i.e., for reconstructing occluded objects from time-resolved measurements of indirect light reflections off a wall. While the direct view of…

Image and Video Processing · Electrical Eng. & Systems 2023-07-19 Jonathan Klein , Martin Laurenzis , Matthias B. Hullin , Julian Iseringhausen

Owing to the capability for reliable and all-weather long-range sensing, the fusion of LiDAR and Radar has been widely applied to autonomous vehicles for robust perception. In practical operation, well manually calibrated extrinsic…

Robotics · Computer Science 2025-03-24 Weimin Wang , Yu Du , Ting Yang , Yu Liu