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Results 11 - 20
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106
A Method Using Focal Plane Analysis to Determine the Performance of Reflector Antennas
, 1995
"... Re°ector antenna optimization schemes using array feeds have been used to re-cover antenna losses resulting from antenna distortions and aberrations and to gen-erate contour coverage patterns. Historically, these optimizations have been carried out using the antenna far-fleld scattered patterns. The ..."
Abstract
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Cited by 1 (1 self)
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Re°ector antenna optimization schemes using array feeds have been used to re-cover antenna losses resulting from antenna distortions and aberrations and to gen-erate contour coverage patterns. Historically, these optimizations have been carried out using the antenna far-fleld scattered patterns
SLAC-PUB-12290 Focal plane metrology for the LSST camera
"... Meeting the science goals for the Large Synoptic Survey Telescope (LSST) translates into a demanding set of imaging performance requirements for the optical system over a wide (3.5 ◦ ) field of view. In turn, meeting those imaging requirements necessitates maintaining precise control of the focal pl ..."
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plane surface (10 µm P-V)overthe entire field of view (640 mm diameter) at the operating temperature (T ∼-100 ◦ C) and over the operational elevation angle range. We briefly describe the heirarchical design approach for the LSST Camera focal plane and the baseline design for assembling the flat focal
Focal-Plane Image and Beam Quality Sensors for Adaptive Optics
"... Control of adaptive optical elements for real-time wavefront phase distortion compen-sation is a rapidly growing field of research and technology development. Wavefront cor-rection is essential for reliable long distance, near-ground laser communication as well as for imaging extended objects over l ..."
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to the requirements of high resolution, real-time adaptive optical systems. In this paper we introduce two VLSI focal-plane sensors that supply image and beam quality metrics to an adaptive controller that performs parallel perturbative stochastic gradient descent on a spatial phase modulator in the control loop
OPTICAL CHARACTERISTICS OF ND:YAG OPTICS AND DISTORTIONS AT HIGH POWER
"... The intensity profile and beam caustics of a fiber coupled high power Nd:YAG laser beam through a lens system are studied. The thermal lensing effect and its influence on the beam profile and focal position are discussed. Asymmetry of the intensity profile in planes above and below the focal plane i ..."
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Cited by 1 (0 self)
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The intensity profile and beam caustics of a fiber coupled high power Nd:YAG laser beam through a lens system are studied. The thermal lensing effect and its influence on the beam profile and focal position are discussed. Asymmetry of the intensity profile in planes above and below the focal plane
Camera Image plane Nodal Point
"... • Primarily, finding the quantities internal to the camera that affect the imaging process § Position of image center in the image • It is typically not at (width/2, height/2) of image § Focal length § Different scaling factors for row pixels and column pixels § Skew factor § Lens distortion (pin-cu ..."
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• Primarily, finding the quantities internal to the camera that affect the imaging process § Position of image center in the image • It is typically not at (width/2, height/2) of image § Focal length § Different scaling factors for row pixels and column pixels § Skew factor § Lens distortion (pin
Impact of distortions on fiber position location in the Dark Energy Spectroscopic Instrument
"... ABSTRACT The Dark Energy Spectroscopic Instrument, to be located at the prime focus of the Mayall telescope, includes a wide field corrector, a 5000 fiber positioner system, and a fiber view camera. The mapping of the sky to the focal plane, needed to position the fibers accurately, is described in ..."
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ABSTRACT The Dark Energy Spectroscopic Instrument, to be located at the prime focus of the Mayall telescope, includes a wide field corrector, a 5000 fiber positioner system, and a fiber view camera. The mapping of the sky to the focal plane, needed to position the fibers accurately, is described
Semiautomatic 3-D model extraction from uncalibrated 2-D camera views
- in Proc. of the SPIE Symposium on Electronic Imaging
, 1995
"... Scenes that contain every-day man-made objects often possess sets of parallel lines and orthogonal planes, the projective features of which possess enough structural information to constrain possible scene element geometries as well as a camera's intrinsic and extrinsic parameters. In particula ..."
Abstract
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Cited by 63 (3 self)
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Scenes that contain every-day man-made objects often possess sets of parallel lines and orthogonal planes, the projective features of which possess enough structural information to constrain possible scene element geometries as well as a camera's intrinsic and extrinsic parameters
QUANTIFYING THE DISTORTION OF DISTANCE OBSERVATIONS CAUSED BY SCATTERING IN TIME-OF-FLIGHT RANGE CAMERAS
"... Time-of-flight range cameras simultaneously gather object distances for all pixels of a focal plane array by evaluating the round-trip time of an emitted signal. In contrast to competing techniques, cameras combining continuously emitted, amplitude modulated signals and Photonic Mixer Devices (PMD, ..."
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Time-of-flight range cameras simultaneously gather object distances for all pixels of a focal plane array by evaluating the round-trip time of an emitted signal. In contrast to competing techniques, cameras combining continuously emitted, amplitude modulated signals and Photonic Mixer Devices (PMD
Microelectromechanical Systems (MEMS) Actuated Wave Front Correcting Subreflector: Distortion Compensation for Large Reflector Antennas
"... Abstract-Gain loss in large reflector antennas due to main reflector surface distortion is a significant problem in both ground and spacecraft antennas. There are two aspects that need to be considered: 1) Since the shape of the main reflector surface is generally not known it is necessary to determ ..."
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feed placed in the focal plane of the reflector system and 3) Small probes placed on the subreflector. It was demonstrated that all three methods can recover the main reflector distortion with the subreflector probe method seeming to offer the simplest (least number of probes and minimal computation
Experimental Comparison of Tracking Algorithms in the Presence of Aircraft Boundary-Layer Distortions for an Emulated Free-Space Laser Communications Link
"... We report on experiments comparing different focal plane array (FPA) tracking algorithms for emulated laser communications links between an aircraft and spacecraft. The links include look-angle-dependent phase distur-bances caused by boundary-layer turbulence replicated using a deformable mirror. Im ..."
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We report on experiments comparing different focal plane array (FPA) tracking algorithms for emulated laser communications links between an aircraft and spacecraft. The links include look-angle-dependent phase distur-bances caused by boundary-layer turbulence replicated using a deformable mirror
Results 11 - 20
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106
