Results 1 to 10 of about 70 (70)
Quantum-accelerated imaging of N stars [PDF]
Optics Letters, 2021 Imaging point sources with low angular separation near or below the Rayleigh criterion are important in astronomy, e.g., in the search for habitable exoplanets near stars. However, the measurement time required to resolve stars in the sub-Rayleigh region via traditional direct imaging is usually prohibitive. Here we propose quantum-accelerated imaging (
Fanglin Bao +3 more
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Imaging Stars with Quantum Error Correction
Physical Review Letters, 2022 comments are ...
Zixin Huang +2 more
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Blurred Star Image Processing for Star Sensors under Dynamic Conditions [PDF]
Sensors, 2012 The precision of star point location is significant to identify the star map and to acquire the aircraft attitude for star sensors. Under dynamic conditions, star images are not only corrupted by various noises, but also blurred due to the angular rate of the star sensor.
Lei Guo, Weina Zhang, Wei Quan
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Single TrAjectory Radial (STAR) imaging [PDF]
Magnetic Resonance in Medicine, 2004 AbstractThe number of MRI applications that use radial k‐space data acquisition have been increasing because of their inherent robustness to motion‐induced reconstruction image artifacts relative to Cartesian acquisition methods. However, images reconstructed from radial data are more prone to image degrading effects due to magnetic field ...
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Infrared imaging of late-type stars [PDF]
Monthly Notices of the Royal Astronomical Society, 1996 Infrared imaging properties of dusty winds around late-type stars are investigated in detail, employing a self-consistent model that couples the equations of motion and radiative transfer. Because of general scaling properties, the angular profiles of surface brightness are self-similar. In any given star, the profile shape is determined essentially by
Ivezic, Zeljko, Elitzur, Moshe
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Star-image Centering with Deep Learning: HST/WFPC2 Images
Publications of the Astronomical Society of the Pacific, 2023 Abstract A deep learning (DL) algorithm is built and tested for its ability to determine centers of star images in HST/WFPC2 exposures, in filters F555W and F814W. These archival observations hold great potential for proper-motion studies, but the undersampling in the camera’s detectors presents challenges for conventional centering ...
Dana I. Casetti-Dinescu +4 more
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Star test image-sampling polarimeter
Optics Express, 2016 We present an analysis and test of an image sampling polarimeter based on the concept of Star Test Polarimetry first introduced by Ramkhalawon. The method makes use of a stress engineered optical element (SEO) placed in the pupil plane of an optical system to induce a polarization dependent point spread function (PSF) at the detector.
Brandon G, Zimmerman, Thomas G, Brown
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Processing Centroids of Smearing Star Image of Star Sensor [PDF]
Mathematical Problems in Engineering, 2014 A novel method was presented for increasing the accuracy of subpixel centroid estimation for smearing star image. Model of the smearing trajectory of smearing star was built. It helped to study the analytical form of the errors, caused by image smearing, for centroid estimation.
Yufu Liao +3 more
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Laser Guide Star Adaptive Optics Imaging Polarimetry of Herbig Ae/Be Stars [PDF]
Science, 2004 We have used laser guide star adaptive optics and a near-infrared dual-channel imaging polarimeter to observe light scattered in the circumstellar environment of Herbig Ae/Be stars on scales of 100 to 300 astronomical units. We revealed a strongly polarized, biconical nebula 10 arc seconds (6000 astronomical units) in diameter around the star LkHα 198 ...
Perrin, Marshall D. +7 more
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Radio Imaging of Symbiotic Stars [PDF]
International Astronomical Union Colloquium, 1988 AbstractA brief review of radio observations of individual symbiotic stars is presented, with emphasis on radio imaging of the circumstellar nebulae. The ionized nebulae are catagorized into two types: outburst ejecta and stellar winds. Among the ejecta-type there is a strong tendency for bipolar or jet morphology. In the case of the quiescent, stellar
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