Results 21 to 30 of about 16,225 (252)
Design Considerations for a Highly Segmented Mirror [PDF]
, 2003 Design issues for a 30-m highly segmented mirror are explored, with emphasis on parametric models of simple, inexpensive segments. A mirror with many small segments offers cost savings through quantity production and permits high-order active and ...
Padin, Stephen
core +1 more source
, 2014 The limiting magnitude is a key issue for optical interferometry. Pairwise fringe trackers based on the integrated optics concepts used for example in GRAVITY seem limited to about K=10.5 with the 8m Unit Telescopes of the VLTI, and there is a general ...
Benkhaldoum, Zouhair +8 more
core +1 more source
Atmospheric coherence times in interferometry: definition and measurement [PDF]
, 2006 Current and future ground-based interferometers require knowledge of the atmospheric time constant t_0, but this parameter has diverse definitions. Moreover, adequate techniques for monitoring t_0 still have to be implemented.
A. Kellerer +18 more
core +2 more sources
Mode-Voltage Constrained Control for Adaptive Optics System
IEEE Photonics JournalIn the adaptive optics system of astronomical observation, the deformable mirror and the tip/tilt mirror are coupled during the correction process.
Ruitao Wang +7 more
doaj +1 more source
Sensing and control of segmented mirrors with a pyramid wavefront sensor in the presence of spiders
, 2017 The segmentation of the telescope pupil (by spiders & the segmented M4) create areas of phase isolated by the width of the spiders on the wavefront sensor (WFS), breaking the spatial continuity of the wavefront.
Clarke, Fraser +11 more
core +1 more source
Atmospheric tomography with separate minimum variance laser and natural guide star mode control [PDF]
, 2009 This paper introduces a novel, computationally efficient, and practical atmospheric tomography wavefront control architecture with separate minimum variance laser and natural guide star mode estimation.
Ellerbroek, B. L., Gilles, L.
core +1 more source
Piston Fuel Film Observations in an Optical Access GDI Engine [PDF]
SAE Technical Paper Series, 2001 <div class="htmlview paragraph">A gasoline direct injection fuel spray was observed using a fired, optical access, square cross-section single cylinder research engine and high-speed video imaging. Spray interaction with the piston is described qualitatively, and the results are compared with Computational Fluid Dynamics (CFD) simulation results ...
Rolf B. Karlsson, John B. Heywood
openaire +1 more source
Shack-Hartmann wavefront sensing with elongated sodium laser beacons: centroiding versus matched filtering [PDF]
, 2006 We describe modeling and simulation results for the Thirty Meter Telescope on the degradation of sodium laser guide star Shack-Hartmann wavefront sensor measurement accuracy that will occur due to the spatial structure and temporal variations of the ...
Ellerbroek, Brent, Gilles, Luc
core +1 more source
The PRIMA fringe sensor unit [PDF]
, 2009 The Fringe Sensor Unit (FSU) is the central element of the Phase Referenced Imaging and Micro-arcsecond Astrometry (PRIMA) dual-feed facility and provides fringe sensing for all observation modes, comprising off-axis fringe tracking, phase referenced ...
Barry +33 more
core +2 more sources
Advanced Functional Materials, EarlyView.Biofabrication aims at providing innovative technologies and tools for the fabrication of tissue‐like constructs for tissue engineering and regenerative medicine applications. By integrating multiple biofabrication technologies, such as 3D (bio) printing with fiber fabrication methods, it would be more realistic to reconstruct native tissue's ...
Waseem Kitana +2 more
wiley +1 more source