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This paper presents a robust non-linear state estimator for autonomous surface vehicles, where the movement is restricted to the horizontal plane. It is assumed that only the vehicle position and orientation can be measured, being the…

Systems and Control · Electrical Eng. & Systems 2024-02-07 Guillermo Bejarano , Sufiyan N-Yo , Luis Orihuela

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

Following the tracks of Malbet, Yu, & Shao (1995} on dark hole algorithms, we present analytical methods to measure and correct the speckle noise behind an ideal coronagraph. We show that, in a low aberration regime, wavefront sensing can…

Astrophysics · Physics 2009-11-11 Pascal Borde , Wesley Traub

We designed and built a new astronomical photo-polarimeter that can measure linear polarization simultaneously in three spectral bands. It has a Calcite beamdisplacement prism as the analyzer. The ordinary and extra-ordinary emerging beams…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 G. Srinivasulu , A. V. Raveendran , S. Muneer , M. V. Mekkaden , N. Jayavel , M. R. Somashekar , K. Sagayanathan , S. Ramamoorthy , M. J. Rosario , K. Jayakumar

As new large-scale astronomical surveys greatly increase the number of objects targeted and discoveries made, the requirement for efficient follow-up observations is crucial. Adaptive optics imaging, which compensates for the image-blurring…

In this paper, we introduce a moving object detection algorithm for fisheye cameras used in autonomous driving. We reformulate the three commonly used constraints in rectilinear images (epipolar, positive depth and positive height…

Computer Vision and Pattern Recognition · Computer Science 2020-03-09 Letizia Mariotti , Ciaran Hughes

Laser guide stars with adaptive optics allow astronomical image correction in the absence of a natural guide star. Single guide star systems with a star created in the earth's sodium layer can be used to correct the wavefront in the near…

Astrophysics · Physics 2009-11-11 S. Rabien , F. Eisenhauer , R. Genzel , R. I. Davies , T. Ott

A form of prime focus corrector for the Gregory system is proposed that provides the sub-arcsecond field of view up to 3 degrees in diameter for the spectral range 0.35-0.90 microns. The corrector includes five lenses made of same glass…

Astrophysics · Physics 2009-11-11 V. Yu. Terebizh

With 3D sensing becoming cheaper, environment-aware and visually-guided robot arms capable of safely working in collaboration with humans will become common. However, a reliable calibration is needed, both for camera internal calibration,…

Robotics · Computer Science 2019-02-18 Justinas Miseikis , Kyrre Glette , Ole Jakob Elle , Jim Torresen

The structured light projection technique is a representative active method for 3-D reconstruction, but many researchers face challenges with the intricate projector calibration process. To address this complexity, we employs an additional…

Optics · Physics 2024-03-05 Seung-Jae Son , Yatong An , Jae-Sang Hyun

Calibration of sensors is fundamental to robust performance for intelligent vehicles. In natural environments, disturbances can easily challenge calibration. One possibility is to use natural objects of known shape to recalibrate sensors.…

Computer Vision and Pattern Recognition · Computer Science 2021-03-22 Yunhai Han , Yuhan Liu , David Paz , Henrik Christensen

For a class of uncertain systems with large-error sensing, the low-order stable signal corrector and observer are presented for signal correction and uncertainty estimation according to completely decoupling estimation. The signal corrector…

Systems and Control · Electrical Eng. & Systems 2022-08-12 Xinhua Wang

Nonlinear optical responses are becoming increasingly relevant for characterizing the symmetries and quantum geometry of electronic phases in materials. Here, we develop an expanded diagrammatic scheme for calculating spatially dispersive…

Mesoscale and Nanoscale Physics · Physics 2023-08-16 Steven Gassner , Eugene J. Mele

A new method for absolute polarimetric calibration of large telescopes is presented. The proposed method is highly accurate and is based on the calibration of a small sub-aperture, which is then extended to the full system by means of…

Astrophysics · Physics 2009-11-10 H. Socas-Navarro

In this paper, we propose a novel optimization-based trajectory planner that utilizes spherical harmonics to estimate the collision-free solution space around an agent. The space is estimated using a constrained over-determined…

Robotics · Computer Science 2021-07-16 Steven Patrick , Efstathios Bakolas

To overcome the resolution limit of conventional optics, near field imaging techniques using a negative index flat lens (NIFL) have been previously developed that amplify the evanescent components of the incident field. Here, a technique is…

Optics · Physics 2016-12-23 Wyatt Adams , Durdu Ö. Güney

A modified version of the folded aplanatic Gregory telescope equipped with a spherical two-lens corrector is proposed for observations requiring a high signal-to-noise ratio. The basic telescope model has an aperture of 400 mm (f/3.0), its…

Instrumentation and Methods for Astrophysics · Physics 2017-12-06 V. Yu. Terebizh

Very high dynamical range coronagraphs targeting direct exo-planet detection (10^9 - 10^10 contrast) at small angular separation (few lambda/D units) usually require an input wavefront quality on the order of ten thousandths of wavelength…

Astrophysics · Physics 2009-11-13 J. Nishikawa , L. Abe , N. Murakami , T. Kotani

We present two concepts of deformable mirror to compensate for first order optical aberrations. Deformation systems are designed using both elasticity theory and Finite Element Analysis in order to minimize the number of actuators. Starting…

Instrumentation and Methods for Astrophysics · Physics 2012-09-13 Marie Laslandes , Emmanuel Hugot , Marc Ferrari

Precise simultaneous control of both angular and spatial light-field distributions remains a longstanding challenge in optical design, often requiring complex multi-element configurations. In this work, we propose a compact single-lens…

Optics · Physics 2026-04-02 Yuou Sun , Bailin Deng , Juyong Zhang
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