Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 10 of 10 for “"High-contrast imaging"”.
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High Contrast Imaging: Exoplanet and Low Stellar Mass Populations
… of a re-analysis of archival Spitzer IRAC direct imaging sur- veys encompassing 121 nearby stars. While the small size of Spitzer provides a lower resolution than 8 m class AO-assisted ground-based telescopes, which have been used for constraining the frequency of 0.5 − 13 MJ planets at …
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Adaptive Wavefront Estimation Algorithms for High-Contrast Imaging of Exoplanets
The direct imaging of exoplanets orbiting stars outside our solar system remains one of the crucial tools we have available to answer whether there exists life beyond Earth. The light from an Earth-like exoplanet is approximately ten orders of magnitude dimmer than its host star and hence the …
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Beyond the speckles: New horizons in high-contrast imaging for exoplanet science
Direct imaging of exoplanets offers a uniquely powerful way of characterizing planetary atmospheres, surface conditions, and potential biological markers beyond our solar system. However, the extreme contrast and small angular separations involved present significant observational challenges that …
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Ray-based Physical Optics for the Design of Astronomical Observatories
… designed to image faint stellar companions at high contrast using specialized pupil-plane and image-plane masks. When imaging Earth-like exoplanets at small angular separations, coronagraphs are limited by telescope stability and polarization aberrations. The state of the art handles the …
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Simulation and testing of wavefront reconstruction algorithms for the deformable mirror (DeMi) cubesat
… by their host stars by a factor of 10₁₀, meaning high-contrast imaging is required to see them. Coronagraphs are typically used to block the starlight to achieve high contrast, but atmospheric, thermal, and mechanical aberrations can cause spurious speckles of starlight to contaminate the image. …
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Phase derivative microscopy of biological cells and tissues
… and gradient field microscopy (GFM), generates high contrast images of transparent specimens. These methods utilize spatial light modulation at the Fourier plane of a bright field microscope to optically obtain the derivatives of the phase and increase the contrast of the final image. The …
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Nanocomposite Dispersion: Quantifying the Structure-Function Relationship
… A method is presented that incorporates high-contrast imaging, an emerging scanning electron microscopy technique to visualize conductive nanofillers deep within insulating materials, with various image processing procedures to allow for the quantification and validation of dispersion …
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Multi-dimensional computational imaging from diffraction intensity using deep neural networks
… wavefront aberrations are retrieved for high-contrast imaging of exoplanets using a deep residual neural network, and transparent planar objects behind dynamic scattering media are revealed by a recurrent neural network, both in an end-to-end training fashion. Next, a multi-layered, …
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Weather on Substellar Worlds: A Study of Clouds, Variability and Binarity at the L/T Transition
… observed could be the result of increasing contrast between discrete cloud features and the underlying atmosphere, rather than the development of cloud holes. We highlight the discovery of a T dwarf with 26% variability, and provide a detailed comparison with atmosphere models in order to …
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Accelerating Embedded HOWFSC Algorithms
… demands on space-based processors. Direct imaging requires precise wavefront control to acquire the 1010 contrast necessary to reveal a dim, Earth-like exoplanet. This precise level of control is only possible if high-order wavefront sensing and control (HOWFSC) algorithms are executed with …