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Search Publications by: B. Carol Johnson (Fed)

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Displaying 276 - 300 of 358

A 400 nm to 2500 nm Absolute Spectral Radiance Comparison Using Filter Radiometers

October 1, 1998
Author(s)
Howard W. Yoon, Bettye C. Johnson, D Kelch, S F. Biggar, P R. Spyak
An integrating sphere source developed by MTL Systems, Inc. was calibrated for them by a commercial standards laboratory traceable to the National Institute of Standards and Technology (NIST), resulting in values of spectral radiance in the 400 nm to 2500

Evaluation of Uncertainties in Fundamental Radiometric Measurements

October 1, 1998
Author(s)
Benjamin K. Tsai, Bettye C. Johnson
The uncertainty of measurements is critical in furthering the development of radiometric science and acquiring an increased understanding of its principles. Proper analysis of measurement uncertainties provides an indication of how well the measurements

Initial Results of the Bidirectional Reflectance Characterization Round-Robin in Support of EOS

October 1, 1998
Author(s)
Bettye C. Johnson, P Y. Barnes, Thomas R. O'Brian, James J. Butler, C J. Bruegge, S F. Biggar, P R. Spyak, M M. Pavlov
Laboratory measurements of the bidirecitonal reflectance distribution function (BRDF) of diffusely reflecting samples are required to support calibration in the National Aeronautics and Space Administration's (NASA's) Earth Observing System (EOS) program

Short-Term Stability Measurements of a Germanium Plotodiode Radiometer

October 1, 1998
Author(s)
G Andor, Bettye C. Johnson
This paper describes a general stability measurement method for the short term stability, or repeatability, for radiometers using fixed-point blackbodies [BBs] as radiation sources. A germanium photodiode was used for the detector in the radiometer. The

The 1996 North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers

September 1, 1998
Author(s)
E A. Thompson, B. Carol Johnson, P Disterhoft, D Wardle, E Wu, J Ehramjian, J Tusson, T Mestechkina, M Beaubian, J Gibson, D Hayes, J DeLuisi, E A. Early, W Mou
Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. To assess the ability of

The NIST EOS Thermal-Infrared Transfer Radiometer

August 1, 1998
Author(s)
Joseph P. Rice, Bettye C. Johnson
A portable thermal infrared transfer radiometer (TXR) has been developed for use in comparisons and scale verifications of sources used to calibrate thermal- infrared (TIR) channels of the National Aeronautics and Space Administration's (NASA's) Earth