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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

We investigate interferometric techniques to estimate the deflection angle of an optical beam and compare them to the direct detection of the beam deflection. We show that quantum metrology methods lead to a unifying treatment for both…

Quantum Physics · Physics 2020-08-12 S. P. Walborn , G. H. Aguilar , P. L. Saldanha , L. Davidovich , R. L. de Matos Filho

Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the…

Accurate calibration is crucial for using multiple cameras to triangulate the position of objects precisely. However, it is also a time-consuming process that needs to be repeated for every displacement of the cameras. The standard approach…

Robotics · Computer Science 2024-04-04 Thomas Gossard , Andreas Ziegler , Levin Kolmar , Jonas Tebbe , Andreas Zell

6D pose estimation of textureless shiny objects has become an essential problem in many robotic applications. Many pose estimators require high-quality depth data, often measured by structured light cameras. However, when objects have shiny…

Robotics · Computer Science 2023-08-29 Jun Yang , Jian Yao , Steven L. Waslander

Nonlinear computation is essential for various information processing tasks. Optical implementations are attractive because passive light propagation can manipulate high-dimensional signals with extreme throughput and parallelism; yet…

The wavelength calibration of spectrographs is an essential but challenging task in many disciplines. Calibration is traditionally accomplished by imaging the spectrum of a light source containing features that are known to appear at…

Instrumentation and Methods for Astrophysics · Physics 2018-04-04 Neil Thomas

Collimator detection remains a challenging task in X-ray systems with unreliable or non-available information about the detectors position relative to the source. This paper presents a physically motivated image processing pipeline for…

Computer Vision and Pattern Recognition · Computer Science 2024-11-18 Benjamin El-Zein , Dominik Eckert , Thomas Weber , Maximilian Rohleder , Ludwig Ritschl , Steffen Kappler , Andreas Maier

Combining image sensor simulation tools (e.g., ISETCam) with physically based ray tracing (e.g., PBRT) offers possibilities for designing and evaluating novel imaging systems as well as for synthesizing physically accurate, labeled images…

Image and Video Processing · Electrical Eng. & Systems 2022-06-29 Thomas Goossens , Zheng Lyu , Jamyuen Ko , Gordon Wan , Joyce Farrell , Brian Wandell

ILC detectors are required to have unprecedented precision. Achieving this requires significant investment for test beam activities to complete the detector R&D needed, to test prototypes and (later) to qualify final detector system…

Instrumentation and Detectors · Physics 2010-07-16 Kiyotomo Kawagoe

Interferometric displacement measurements, especially in space interferometry applications, face challenges from thermal expansion. Bonded assemblies of ultra-low thermal expansion glass-ceramics offer a solution; however, transitioning…

Optical diffraction tomography is an indispensable tool for studying objects in three-dimensions due to its ability to accurately reconstruct scattering objects. Until now this technique has been limited to coherent light because spatial…

Object-motion-based speckle correlation can recover hidden objects from any inhomogeneous medium, which takes advantage of the inherent connection that the cross-correlation between speckle patterns can reflect the autocorrelation of…

Optics · Physics 2023-12-01 Zhao Wang , Rui Ma , Mingzhu She , Anda Shi , Weili Zhang

Object triangulation, 3-D object tracking, feature correspondence, and camera calibration are key problems for estimation from camera networks. This paper addresses these problems within a unified Bayesian framework for joint multi-object…

Computer Vision and Pattern Recognition · Computer Science 2014-10-10 Jeremie Houssineau , Daniel Clark , Spela Ivekovic , Chee Sing Lee , Jose Franco

Beam steering is the process involving the calibration of the angle and position at which a particle accelerator's electron beam is incident upon the x-ray target with respect to the rotation axis of the collimator. Beam Steering is an…

Accelerator Physics · Physics 2023-11-14 Isaac Kante

High precision differential astrometry assesses the positions, distances, and motions of celestial objects in relation to the stars. The focal plane of such space telescope must be calibrated with a precision down to the level of 1e-5 pixel…

Instrumentation and Methods for Astrophysics · Physics 2024-10-30 Fabrice Pancher , Sebastien Soler , Fabien Malbet , Manon Lizzana , Pierre Kern , Thierry Lepine , Alain Leger

We propose a precise ellipsometric method for the investigation of coherent light with a small ellipticity. The main feature of this method is the use of compensators with phase delays providing the maximum accuracy of measurements for the…

Instrumentation and Detectors · Physics 2017-06-21 Nazar Al-wassiti , Evelina Bibikova , Nataliya Kundikova

Space-based coronagraphs for future earth-like planet detection will require focal plane wavefront control techniques to achieve the necessary contrast levels. These correction algorithms are iterative and the control methods require an…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Tyler D. Groff , N. Jeremy Kasdin

We present the results of a study along with a first prototype of a high precision system (? 1 arcsec) for pointing and tracking light (near-infrared) telescopes on board stratospheric balloons. Such a system is essentially composed by a…

Instrumentation and Methods for Astrophysics · Physics 2011-04-13 M. Ricci , F. Pedichini , D. Lorenzetti

While model-based reconstruction methods have been successfully applied to flat-panel cone-beam CT (FP-CBCT) systems, typical implementations ignore both spatial correlations in the projection data as well as system blurs due to the…

Medical Physics · Physics 2017-06-20 Steven Tilley , Jeffrey H. Siewerdsen , J. Webster Stayman