Dr. David A. Vaughnn Profile

Dr. David A. Vaughnn

Optics Branch Head at NASA Goddard Space Flight Ctr

SPIE Involvement:

Author

Proceedings Article | 19 September 2016 Presentation + Paper

Advanced topographic laser altimeter system (ATLAS) receiver telescope assembly (RTA) and transmitter alignment and test

John Hagopian, Matthew Bolcar, John Chambers, Allen Crane, Bente Eegholm, Tyler Evans, Samuel Hetherington, Eric Mentzell, Patrick Thompson, Luis Ramos-Izquierdo, David Vaughnn

Proceedings Volume 9972, 997207 (2016) https://doi.org/10.1117/12.2240241

KEYWORDS: Space telescopes, Telescopes, Optical fibers, Receivers, Transmitters, Diffractive optical elements, Collimators, Wavefronts, Mirrors, Interferometers

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The sole instrument on NASA’s ICESat-2 spacecraft shown in Figure 1 will be the Advanced Topographic Laser Altimeter System (ATLAS)¹. The ATLAS is a Light Detection and Ranging (LIDAR) instrument; it measures the time of flight of the six transmitted laser beams to the Earth and back to determine altitude for geospatial mapping of global ice. The ATLAS laser beam is split into 6 main beams by a Diffractive Optical Element (DOE) that are reflected off of the earth and imaged by an 800 mm diameter Receiver Telescope Assembly (RTA). The RTA is composed of a 2-mirror telescope and Aft Optics Assembly (AOA) that collects and focuses the light from the 6 probe beams into 6 science fibers. Each fiber optic has a field of view on the earth that subtends 83 micro Radians. The light collected by each fiber is detected by a photomultiplier and timing related to a master clock to determine time of flight and therefore distance. The collection of the light from the 6 laser spots projected to the ground allows for dense cross track sampling to provide for slope measurements of ice fields. NASA LIDAR instruments typically utilize telescopes that are not diffraction limited since they function as a light collector rather than imaging function. The more challenging requirements of the ATLAS instrument require better performance of the telescope at the ¼ wave level to provide for improved sampling and signal to noise. NASA Goddard Space Flight Center (GSFC) contracted the build of the telescope to General Dynamics (GD). GD fabricated and tested the flight and flight spare telescope and then integrated the government supplied AOA for testing of the RTA before and after vibration qualification. The RTA was then delivered to GSFC for independent verification and testing over expected thermal vacuum conditions. The testing at GSFC included a measurement of the RTA wavefront error and encircled energy in several orientations to determine the expected zero gravity figure, encircled energy, back focal length and plate scale. In addition, the science fibers had to be aligned to within 10 micro Radians of the projected laser spots to provide adequate margin for operations on-orbit. This paper summarizes the independent testing and alignment of the fibers performed at the GSFC.

Proceedings Article | 17 December 2014 Paper

Optical design of the WFIRST-AFTA wide-field instrument

Bert Pasquale, David Content, Jeffery Kruk, David Vaughnn, Qian Gong, Joseph Howard, Alden Jurling, Len Seals, Eric Mentzell, Nerses Armani, Gary Kuan

Proceedings Volume 9293, 929305 (2014) https://doi.org/10.1117/12.2177847

KEYWORDS: Mirrors, Telescopes, Optical design, Space telescopes, Staring arrays, Sensors, James Webb Space Telescope, Infrared telescopes, Observatories, Ray tracing

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Proceedings Article | 26 September 2013 Paper

Wide field instrument preliminary design for the Wide Field InfraRed Survey Telescope

David Content, Nerses Armani, Charles Baker, Clifton Jackson, Duncan Kahle, Jeffrey Kruk, John Lehan, Mark Melton, Eric Mentzell, Joseph Miko, David Palace, Bert Pasquale, Hume Peabody, Brian Smith, Walter Smith, Jeffrey Stewart, David Vaughnn, Augustyn Waczynski, Thomas Wallace

Proceedings Volume 8860, 88600F (2013) https://doi.org/10.1117/12.2025496

KEYWORDS: Space telescopes, Telescopes, Space operations, Electronics, Optical benches, Optical instrument design, Mirrors, Imaging spectroscopy, Staring arrays, Composites

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Proceedings Article | 31 August 2006 Paper

Actual field curvature and isoquals

David Vaughnn, Robert Mark

Proceedings Volume 6288, 62880E (2006) https://doi.org/10.1117/12.681436

KEYWORDS: Monochromatic aberrations, Diffraction, Image quality, Wavefronts, Modulation transfer functions, Spatial frequencies, Optical design, Ray tracing, Solids, Geometrical optics

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Proceedings Article | 29 September 2004 Paper

Filter solarization, understanding, and mitigating degradation

David Vaughnn, Gary Poczulp

Proceedings Volume 5529, (2004) https://doi.org/10.1117/12.555016

KEYWORDS: Optical filters, Ultraviolet radiation, Lamps, Interference filters, Data modeling, Glasses, Neodymium, Silica, Manufacturing, Dielectrics

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Proceedings Article | 10 December 2001 Paper

Rapid Confocal Sensor: a noncontact profilometer for fast 3D submicron inspection and metrology of large formats

David Vaughnn, Cory Watkins, Dick Anderson

Proceedings Volume 4449, (2001) https://doi.org/10.1117/12.450092

KEYWORDS: Confocal microscopy, Sensors, Inspection, Beam splitters, Imaging systems, 3D metrology, Cameras, Semiconducting wafers, Metrology, Fiber optic illuminators

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Proceedings Article | 16 August 2000 Paper

Four-quadrant error sensor that yields position and focus utilizing an internal mirrorlette array

David Vaughnn, Charles Claver, Eric Richardson

Proceedings Volume 4008, (2000) https://doi.org/10.1117/12.395460

KEYWORDS: Sensors, Monochromatic aberrations, Telescopes, Prisms, Avalanche photodetectors, Beam splitters, Fiber optics, Image sensors, Optical components, Signal to noise ratio

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Proceedings Article | 9 July 1998 Paper

New wide-field corrector for the Kitt Peak Mayall 4-m telescope

George Jacoby, Ming Liang, David Vaughnn, Richard Reed, Taft Armandroff

Proceedings Volume 3355, (1998) https://doi.org/10.1117/12.316845

KEYWORDS: Prisms, Telescopes, Charge-coupled devices, Optical components, Sensors, Optical coatings, Image quality, Glasses, Optical filters, Bandpass filters

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Proceedings Article | 11 November 1996 Paper

Identification and analyses of phosphorescent materials for use in optical systems and instrumentation

David Vaughnn

Proceedings Volume 2864, (1996) https://doi.org/10.1117/12.258333

KEYWORDS: Phosphorescence, Glasses, Manufacturing, Stray light, Solids, Charge-coupled devices, Phosphorescent materials, Adhesives, Light sources and illumination, Camera shutters

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Proceedings Article | 11 November 1996 Paper

Electrostatic application of black flocking for reducing grazing incidence reflections

David Vaughnn, Jay Tome

Proceedings Volume 2864, (1996) https://doi.org/10.1117/12.258332

KEYWORDS: Adhesives, Grazing incidence, Bidirectional reflectance transmission function, Aluminum, Reflectivity, Scattering, Light scattering, Stray light, Epoxies, Visualization

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