Michael Lloyd-Hart

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We show in benchtop experiments that wave-front phase estimation by phase diversity can be significantly improved by simultaneous amplitude estimation. Processing speed, which will be important for real-time wave-front control applications, can be enhanced by use of small-format detectors with pixels that do not fully sample the diffraction limit. Using an(More)
We report a multiframe blind deconvolution algorithm that we have developed for imaging through the atmosphere. The algorithm has been parallelized to a significant degree for execution on high-performance computers, with an emphasis on distributed-memory systems so that it can be hosted on commodity clusters. As a result, image restorations can be obtained(More)
We investigate the performance of a general multiconjugate adaptive optics (MCAO) system in which signals from multiple reference beacons are used to drive several deformable mirrors in the optical beam train. Taking an analytic approach that yields a detailed view of the effects of low-order aberration modes defined over the metapupil, we show that in the(More)
— The use of high speed adaptive secondary mirrors (AS) in cassegrain or gregorian telescopes shows high optical efficiency as well as the possibility to make Adaptive Optics (AO) available at all foci. After 4 years of extensive and successful use of a 336-actuator AS (MMT336) at the Multi Mirror Telescope (MMT), the need for faster control methods of the(More)
We describe an innovative implementation of the Shack-Hartmann wave-front sensor that is designed to correct the perspective elongation of a laser guide beacon in adaptive optics. Subapertures are defined by the segments of a deformable mirror rather than by a conventional lenslet array. A bias tilt on each segment separates the beacon images on the(More)
e can trace our interest in recording and understanding the stars and planets back thousands of years. But it was not until the early 17th century with the telescope's invention that we recorded the first astronomical " images, " hand drawings of our Moon's surfaces , the Sun, Venus, and Saturn, and Jupiter's satellites. Detailed drawings by Galileo Galilei(More)
A simple scheme is proposed to increase the corrected field of view of a telescope equipped with adaptive optics. The optical system's entrance pupil is projected forward into the atmosphere and is slightly reduced in size. The field in any given direction is then imaged through just a portion of the main aperture, while the full aperture is used to collect(More)
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