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Search Publications by: Steven W. Brown (Fed)

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Displaying 26 - 50 of 162

Supercontinuum Sources for Metrology

June 2, 2009
Author(s)
John T. Woodward IV, Allan W. Smith, Colleen A. Jenkins, Chungsan Lin, Steven W. Brown, Keith R. Lykke
Supercontinuum (SC) sources are novel laser-based sources that generate a broad, white-light continuum in single mode photonic crystal fibers. Currently, up to 6 W of optical power is available, spanning the spectral range from 460 nm to 2500 nm. Advances

Stray Light Correction of the Marine Optical System

January 1, 2009
Author(s)
M Feinholz, S Flora, M Yarbrough, Keith R. Lykke, Steven W. Brown, B. Carol Johnson, Dennis Clark
The Marine Optical System is a spectrograph-based sensor used in the Marine Optical Buoy for the vicarious calibration of ocean color satellite sensors. It is also deployed from ships in instruments used to develop bio-optical algorithms that relate the

The Marine Optical BuoY (MOBY) Radiometric Calibration and Uncertainty Budget for Ocean Color Satellite Sensor Vicarious Calibration

December 31, 2008
Author(s)
M Feinholz, B. Carol Johnson, Steven W. Brown, S Flora, M Yarbrough, Terrance Houlihan, D Peters, Yong S. Kim, J Mueller, Dennis Clark
For the past decade, the Marine Optical Buoy (MOBY), an autonomous radiometric buoy stationed in the waters off Lanai, Hawaii, has been the primary in-water oceanic observatory for the vicarious calibration of the U. S. satellite ocean color sensors

Metrology for Remote Sensing Radiometry

October 16, 2008
Author(s)
B. Carol Johnson, Steven W. Brown, Joseph P. Rice
Metrology, the science of measurement, is discussed in terms of measurements of radiant flux and associated quantities. Radiometric measurements are naturally remote, that is, they are non-contact. A broad application is Earth science, as global

Measurement science for climate remote sensing

August 20, 2008
Author(s)
Gerald T. Fraser, Steven W. Brown, Raju V. Datla, Bettye C. Johnson, Keith R. Lykke, Joseph P. Rice
The Earth s climate is very complex and highly variable, making it difficult to measure and model small changes that occur over decadal and longer time scales. The resulting uncertainties in measurement and modeling underlie the longterm debate over the

Dynamically Programmable Digital Tissue Phantoms

December 31, 2007
Author(s)
Steven W. Brown, Joseph P. Rice, David W. Allen, Maritoni A. Litorja, Karel Zuzak, Edward Livingston
As optical imaging modalities gain acceptance for medical diagnostics and become common in clinical applications, standardized protocols to quantitatively assess optical sensor performance are required to ensure commonality in measurements and to validate

Thermodynamic Radiation Thermometry for the Next SI

November 15, 2007
Author(s)
Howard W. Yoon, Charles E. Gibson, V B. Khromchenko, George P. Eppeldauer, Robert R. Bousquet, Steven W. Brown, Keith R. Lykke
We describe the construction, the calibration and the use of the NIST Thermodynamic Radiation Thermometer (TRT) to measure the temperature of the gold-freezing temperature blackbody and a variable-temperature blackbody from 800 ?C to 2700 ?C. These

Characterization and Correction of Stray Light in Optical Instruments

November 1, 2007
Author(s)
Yuqin Zong, Steven W. Brown, G Meister, R Barnes, Keith R. Lykke
Improperly imaged, or scattered, optical radiation within an instrument is difficult to properly characterize and is often the dominant residual source of measurement error. Scattered light can originate from the spectral components of a point source and

The Marine Optical BuoY (MOBY) Radiometric Calibration and Uncertainty Budget for Ocean Color Satellite Sensor Vicarious Calibration

November 1, 2007
Author(s)
Steven W. Brown, S Flora, M Feinholz, M Yarbrough, Terrance Houlihan, D Peters, Yong S. Kim, J Mueller, Bettye C. Johnson, Dennis Clark
For the past decade, the Marine Optical Buoy (MOBY), an autonomous radiometric buoy stationed in the waters off Lanai, Hawaii, has been the primary in-water oceanic observatory for the vicarious calibration of U. S. satellite ocean color sensors, including

Evaluation of a Portable Hyperspectral Imager for Medical Imaging Applications

October 2, 2007
Author(s)
David W. Allen, Maritoni A. Litorja, Steven W. Brown, Joseph P. Rice, Yuqin Zong
Portable hyperspectral imagers are becoming commonly available as a commercial product. A liquid crystal tunable filter based CCD imager was evaluated and characterized for spectral stray light using a tunable laser facility. The hyperspectral imager is

System-Level Pre-Launch Calibration of Onboard Solar Diffusers

September 26, 2007
Author(s)
R Barnes, Steven W. Brown, Keith R. Lykke, Gerald T. Fraser, James J. Butler
Onboard diffuse reflecting plaques are carried to orbit as radiometric reference standards for Earth-observing satellite instruments. For many instruments the reflectance properties of the plaque are characterized independent of the instrument, and the

A Hyperspectral Image Projector for Hyperspectral Imagers

September 3, 2007
Author(s)
Joseph P. Rice, Steven W. Brown, Jorge E. Neira, Robert R. Bousquet
We have developed and demonstrated a Hyperspectral Image Projector (HIP) intended for system-level validation testing of hyperspectral imagers, including the instrument and any associated spectral unmixing algorithms. HIP, based on the same digital

Absolute Flux Calibrations of Stars

August 30, 2007
Author(s)
Gerald T. Fraser, Steven W. Brown, Howard W. Yoon, Bettye C. Johnson, Keith R. Lykke
Absolute stellar photometry is based on 1970s terrestrial measurements of the star Vega referenced against the Cu fixed-point blackbody. Significant advances in absolute radiometry have been made in the last 30 years that offer the potential to improve

Simultaneous Measurement of Up-Welling Spectral Radiance Using a Fiber-Coupled CCD Spectrograph

August 26, 2007
Author(s)
M Yarbrough, S Flora, M Feinholz, Terrance Houlihan, Yong S. Kim, Steven W. Brown, B. Carol Johnson, Kenneth Voss, Dennis Clark
Determination of the water-leaving spectral radiance using in-water instrumentation requires measurements of the up-welling spectral radiance (Lu) at several depths. If these measurements are separated in time, changes in the measurement conditions result

Correction of Stray Light In Spectroradiometers and Imaging Instruments

July 4, 2007
Author(s)
Yuqin Zong, Steven W. Brown, Keith R. Lykke, Yoshihiro Ohno
Measurement errors from stray light, spectral or spatial, are inevitable and are often the dominant source of error in spectroradiometers and imaging radiometers/photometers. We have developed a simple matrix method for correcting spatial stray light in

Thermodynamic-Temperature Determinations of the Ag and Au Freezing Temperatures Using a Detector-Based Radiation Thermometer

May 20, 2007
Author(s)
Howard W. Yoon, David W. Allen, Charles E. Gibson, Maritoni A. Litorja, Robert D. Saunders, Steven W. Brown, George P. Eppeldauer, Keith R. Lykke
We describe the development of a radiation thermometer calibrated for spectral radiance responsivity using cryogenic, electrical-substitution radiometry to determine the thermodynamic temperatures of the Ag- and Au-freezing temperatures. The absolute

Development of Surgical Lighting for Enhanced Color Contrast

May 14, 2007
Author(s)
Maritoni A. Litorja, Steven W. Brown, Maria E. Nadal, David W. Allen, Alexander Gorbach
The National Institute of Standards and Technology and the National Institutes of Health have started a collaborative study on the development of lighting that will provide enhanced, specific to various tissues, contrast with respect to its surroundings

Compact Anamorphic Imaging Spectrometer

February 9, 2007
Author(s)
P Maciejewski, K Barnard, Rand Swanson, Michael Kehoe, C Smith, Thomas Moon, Robert R. Bousquet, Steven W. Brown, Keith R. Lykke
Deployment of compact hyperspectral imaging sensors on small UAVs has the potential of providing a cost-effective solution for rapid-response target detection and cueing based on time-critical spectral information collected at low altitudes. To address

Hyperspectral Image Projector for Advanced Sensor Characterization

December 4, 2006
Author(s)
Steven W. Brown, Joseph P. Rice, Jorge E. Neira, Bettye C. Johnson
In this work, we describe radiometric platforms able to produce realistic spectral distributions and spatial scenes for the development of application-specific metrics to quantify the performance of sensors and systems. Using these platforms, sensor and

Development of Hyperspectral Image Projectors

November 1, 2006
Author(s)
Joseph P. Rice, Steven W. Brown, Jorge E. Neira
We present design concepts for calibrated hyperspectral image projectors (HIP) and related sources intended for system-level testing of instruments ranging from complex hyperspectral or multispectral imagers to simple filter radiometers. HIP, based on the