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The Keck Planet Imager and Characterizer (KPIC) combines high contrast imaging with high resolution spectroscopy (R~35,000 in K band) to study directly imaged exoplanets and brown dwarfs in unprecedented detail. KPIC aims to spectrally…

Imaging the direct light signal from a faint exoplanet against the overwhelming glare of its host star presents one of the fundamental challenges to modern astronomical instrumentation. Achieving sufficient signal-to-noise for detection by…

Instrumentation and Methods for Astrophysics · Physics 2014-03-05 S. Lacour , P. Tuthill , J. D. Monnier , T. Kotani , L. Gauchet , P. Labeye

Combining the resolving power of long-baseline interferometry with the high-dynamic range capability of nulling still remains the only technique that can directly sense the presence of structures in the innermost regions of extrasolar…

Instrumentation and Methods for Astrophysics · Physics 2018-11-14 Frantz Martinache , Michael J. Ireland

The use of interferometric nulling for the direct characterization of extrasolar planets is an exciting prospect, but one that faces many practical challenges when deployed on telescopes. The largest limitation is the extreme sensitivity of…

Instrumentation and Methods for Astrophysics · Physics 2022-06-13 Nick Cvetojevic , Frantz Martinache , Peter Chingaipe , Romain Laugier , Katarzyna Ławniczuk , Ronald G. Broeke , Roxanne Ligi , Mamadou N'Diaye , David Mary

We investigate methods to calibrate the non-common path aberrations at an adaptive optics system having a wavefront-correcting device working at an extremely high resolution (larger than 150x150). We use focal-plane images collected…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Visa Korkiakoski , Christoph U. Keller , Niek Doelman , Matthew Kenworthy , Gilles Otten , Michel Verhaegen

Linking a coronagraph instrument to a spectrograph via a single mode optical fiber is a pathway towards detailed characterization of exoplanet atmospheres with current and future ground- and space-based telescopes. However, given the…

The next generation of large ground- and space-based optical telescopes will have segmented primary mirrors. Co-phasing the segments requires a sensitive wavefront sensor capable of measuring phase discontinuities. The Zernike wavefront…

Instrumentation and Methods for Astrophysics · Physics 2022-06-29 Maaike A. M. van Kooten , Sam Ragland , Rebecca Jensen-Clem , Yinzi Xin , Jacques-Robert Delorme , J. Kent Wallace

Integral Field Spectrographs (IFS) often require non-trivial calibration techniques to process raw data. The OH Suppressing InfraRed Imaging Spectrograph (OSIRIS) at the W. M. Keck Observatory is a lenslet-based IFS that requires precise…

Instrumentation and Methods for Astrophysics · Physics 2022-07-06 Katelyn Horstman , Michael P. Fitzgerald , James E. Lyke , Sherry C. C. Yeh , Devin S. Chu

Recent high-contrast imaging surveys, looking for planets in young, nearby systems showed evidence of a small number of giant planets at relatively large separation beyond typically 20 au where those surveys are the most sensitive. Access…

We extend our previous demonstration of the first on-sky primary mirror segment closed-loop control on Keck using a vector-Zernike wavefront sensor (vZWFS), which improved the Strehl ratio on the NIRC2 science camera by up to 10 percentage…

The Keck Planet Imager and Characterizer (KPIC), a series of upgrades to the Keck II Adaptive Optics System and Instrument Suite, aims to demonstrate high-resolution spectroscopy of faint exoplanets that are spatially resolved from their…

The means to obtain the adsorption isotherms is a fundamental open problem in competitive chromatography. A modern technique of estimating adsorption isotherms is to solve an inverse problem so that the simulated batch separation coincides…

Signal Processing · Electrical Eng. & Systems 2021-02-03 Chen Xu , Ye Zhang

We present the design concept of the wavelength calibration system for the Habitable-zone Planet Finder instrument (HPF), a precision radial velocity (RV) spectrograph designed to detect terrestrial-mass planets around M-dwarfs. HPF is a…

Instrumentation and Methods for Astrophysics · Physics 2014-08-19 Samuel Halverson , Suvrath Mahadevan , Lawrence Ramsey , Ryan Terrien , Arpita Roy , Christian Schwab , Chad Bender , Fred Hearty , Eric Levi , Steve Osterman , Gabe Ycas , Scott Diddams

This year, a second generation of coronagraphs dedicated to high-contrast direct imaging of exoplanets is starting operations. Among them, SPHERE, installed at the focus of the UT3 Very Large Telescope, reaches unprecedented contrast ratios…

Instrumentation and Methods for Astrophysics · Physics 2015-10-22 H. Le Coroller , M. Nowak , L. Arnold , K. Dohlen , T. Fusco , J. F. Sauvage , A. Vigan

We present a novel method for extrinsically calibrating a camera and a 2D Laser Rangefinder (LRF) whose beams are invisible from the camera image. We show that point-to-plane constraints from a single observation of a V-shaped calibration…

Computer Vision and Pattern Recognition · Computer Science 2018-09-05 Wenbo Dong , Volkan Isler

We study Fock state interferometry, consisting of a Mach-Zehnder Interferometer with two Fock state inputs and photon-number-resolved detection at the two outputs. We show that it allows discrimination of a discrete number of apriori-known…

Quantum Physics · Physics 2021-02-16 Reihaneh Shahrokhshahi , Saikat Guha , Olivier Pfister

We propose VDN-NeRF, a method to train neural radiance fields (NeRFs) for better geometry under non-Lambertian surface and dynamic lighting conditions that cause significant variation in the radiance of a point when viewed from different…

Computer Vision and Pattern Recognition · Computer Science 2023-04-03 Bingfan Zhu , Yanchao Yang , Xulong Wang , Youyi Zheng , Leonidas Guibas

Vessel segmentation is crucial in many medical image applications, such as detecting coronary stenoses, retinal vessel diseases and brain aneurysms. However, achieving high pixel-wise accuracy, complete topology structure and robustness to…

Computer Vision and Pattern Recognition · Computer Science 2023-05-11 Tianyi Shi , Xiaohuan Ding , Wei Zhou , Feng Pan , Zengqiang Yan , Xiang Bai , Xin Yang

This article examines state estimation in discrete-time nonlinear stochastic systems with finite-dimensional states and infinite-dimensional measurements, motivated by real-world applications such as vision-based localization and tracking.…

Systems and Control · Electrical Eng. & Systems 2025-09-24 Maxwell M. Varley , Timothy L. Molloy , Girish N. Nair

Asgard/NOTT (previously Hi-5) is a European Research Council (ERC)-funded project hosted at KU Leuven and a new visitor instrument for the Very Large Telescope Interferometer (VLTI). Its primary goal is to image the snow line region around…