Michael Lloyd-Hart

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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 present the results of mid-infrared nulling interferometric observations of the main-sequence star α Lyr (Vega) using the 6.5 m MMT with its adaptive secondary mirror. From the observations at 10.6 μm, we find that there is no resolved emission from the circumstellar environment (at separations greater than 0.8 AU) above 2.1% (3 σ limit) of the level of(More)
We describe the conceptual design of an advanced laser guide star facility (LGSF) for the Large Binocular Telescope (LBT), to be built in collaboration with the LBT’s international partners. The highest priority goal for the facility is the correction of ground-layer turbulence, providing partial seeing compensation in the near IR bands over a 4 field. In(More)
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)
An adaptive optics system is being built for the 6.5 m MMT conversion telescope on Mt. Hopkins for diffraction-limited observations in the near infrared. At the heart of the system is a deformable secondary mirror which introduces corrections to the optical wavefront. By compensating these errors at the telescope’s secondary, the system has been optimised(More)
We present a new way to sense atmospheric wave-front phase distortion. Short collimated pulses of laser light at ~350nm are projected from a small auxilliary telescope. Rayleigh scattering from each pulse is recorded over a wide range of height through the main telescope aperture in a continuous sequence of fast video frames by a detector conjugate to(More)
The adaptive optics system of the 6.5m MMT with its deformable secondary has seen first light on the sky in November 2002. Since then, it has logged over 30 nights at the telescope and has been used with several scientific cameras and a dedicated IR infrared camera. Results so far are extremely encouraging with Strehls of up to 20% in H-band and 98% in M(More)
Using five independent analytic and Monte Carlo simulation codes, we have studied the performance of wide field ground layer adaptive optics (GLAO), which uses a single, relatively low order deformable mirror to correct the wavefront errors from the lowest altitude turbulence. GLAO concentrates more light from a point source in a smaller area on the science(More)
Adaptive optics to correct current telescopes over wide fields, or future very large telescopes over even narrow fields, will require real-time wavefront measurements made with a constellation of laser beacons. Here we report the first such measurements, made at the 6.5 m MMT with five Rayleigh beacons in a 2 pentagon. Each beacon is made with a pulsed beam(More)