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Search Publications by: Gerald T. Fraser (Fed)

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Displaying 1 - 25 of 156

A Summary of Heat-Flux Sensor Calibration Data

October 12, 2021
Author(s)
A V. Murthy, Gerald T. Fraser, D P. DeWitt
This paper presents a statistical evaluation of the responsivity data on a number of heat-flux sensors, calibrated using an electrical substitution radiometer as a transfer standard up to 5 W cm-2. The sensors, furnished by the customers, were of circular

Sensor Calibration and Characterization to Meet Climate Monitoring Requirements

April 24, 2014
Author(s)
Catherine C. Cooksey, Gerald T. Fraser, Howard W. Yoon
The challenge of detecting small changes in the Earth's climate system over decadal and longer time scales places stringent requirements on environmental monitoring systems. Sensors must be well calibrated and maintain their calibration in challenging

A novel apparatus to measure reflected sunlight from the Moon

September 19, 2013
Author(s)
Claire E. Cramer, Gerald T. Fraser, Keith R. Lykke, John T. Woodward IV, Alan W. Smith
We describe a new apparatus for measuring the spectral irradiance of the Moon at visible wavelengths. Our effort builds upon the United States Geological Survey’s highly successful Robotic Lunar Observatory (ROLO), which determined a precise model for the

Ground-based observatory operations optimized and enhanced by direct atmospheric measurements

July 22, 2010
Author(s)
John T. McGraw, Peter C. Zimmer, Azzam Mansour, Dean C. Hines, Anthony B. Hull, Lisa Rossmann, Daniel C. Zirzow, Steven W. Brown, Gerald T. Fraser, Keith R. Lykke, Allan W. Smith, John T. Woodward IV, Christopher W. Stubbs
Earth's atmosphere represents a turbulent, turbid refractive element for every ground-based telescope. We describe the significantly enhanced and optimized operation of observatories supported by the combination of a lidar and spectrophotometer that allows

Space-based photometric precision from ground-based telescopes

July 1, 2010
Author(s)
Peter C. Zimmer, John T. McGraw, Anthony B. Hull, Daniel C. Zirzow, Steven W. Brown, Claire E. Cramer, Gerald T. Fraser, Keith R. Lykke, Allan W. Smith, John T. Woodward IV, Christopher W. Stubbs, Mark R. Ackermann, Dean C. Hines
Ground-based telescopes supported by lidar and spectrophotometric auxiliary instrumentation can attain space-based precision for all-sky photometry, with uncertainties dominated by fundamental photon counting statistics. Earth‟s atmosphere is a wavelength-

Strategic Plan 2010

April 21, 2010
Author(s)
Gerald T. Fraser
The Optical Technology Division s 2010 Strategic Plan defines the Mission, Vision, and Strategic Elements for the Division. The Strategic Elements consist of Optical Radiation Standards, Optical Measurement Methods, and Optical Measurement Services. The

A proposed global atmospheric monitoring networkbased on standard stars

November 2, 2009
Author(s)
Gerald T. Fraser, Steven W. Brown, Keith R. Lykke, John T. McGraw, Allan W. Smith, John T. Woodward IV, Peter C. Zimmer, Christopher W. Stubbs
The feasibility of developing a network of telescopes to monitor the composition of the nighttime atmosphere using stellar spectrophotometry is explored. Spectral measurements of the extinction of starlight by the atmosphere would allow, for instance

Rotation-Tunneling Spectrum of Deuterated Ammonia Dimer

October 16, 2008
Author(s)
E N. Karyakin, Gerald T. Fraser, J G. Loeser, R J. Saykally
The millimeter and submillimeter-wave molecular-beam spectrum of the perdeuterated ammonia dimer (ND3)2 has been measured between approximately 50 GHz and 400 GHz using an electric-resonance optothermal spectrometer(EROS). As in the case of the (NH3)2, the

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

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

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

Once is Enough in Radiometric Calibrations

February 1, 2007
Author(s)
Gerald T. Fraser, Charles E. Gibson, Howard W. Yoon, Albert C. Parr
The successful development of an Optical Technology Division quality system for optical radiation measurement services has provided the opportunity to reconsider the existing calibration procedures to improve quality and reduce costs. We have instituted

The Microwave Spectrum of a Two-Top Peptide Mimetic: The N-Acetyl Alanine Methyl Ester Molecule

September 14, 2006
Author(s)
I Kleiner, J Demaison, David F. Plusquellic, R D. Suenram, R J. Lavrich, Francis J. Lovas, Gerald T. Fraser, Vadim V. Ilyushin
Rotational spectra of the ground torsional state of the N-acetyl alanine methyl ester molecule, a derivative of the alanine dipeptide biomimetic molecule, have been measured using a mini Fourier transform spectrometer between 10 and 20 GHz as part of a

Achieving Satellite Instrument Calibration for Climate Change (ASIC3)

May 18, 2006
Author(s)
Gerald T. Fraser, Raju V. Datla
The Workshop on Achieving Satellite Instrument Calibration for Climate Change (ASIC3) was a follow-up to a 2002 Workshop (Ohring et al., 2004; Ohring et al., 2005) that had developed the measurement requirements for a number of global climate variables

In-Cavity Calibration of High Heat-Flux Sensors: Experimental Validation

June 9, 2005
Author(s)
A V. Murthy, Gerald T. Fraser, D P. DeWitt
This paper deals with the feasibility of performing primary calibration of heat-flux sensors at high irradiance levels by placing inside the cylindrical cavity of a graphite-tube blackbody. The experimental study comprised of measurements on two Schmidt