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Displaying 151 - 175 of 351

Infrared Spectral Emissivity Characterization Facility at NIST

January 1, 2004

Author(s)

Leonard M. Hanssen, V B. Khromchekno, Sergey Mekhontsev

Spatial and Angular Responsivity Measurements of Photoconductive HgCdTe LWIR Radiometers

January 1, 2004

Author(s)

H Gong, Leonard Hanssen, George P. Eppeldauer

Analytical Evaluation and Correction of Port Loss Error in Integrating Sphere Reflectometers

November 1, 2003

Author(s)

A Prokhorov, Sergey Mekhontsev, Leonard Hanssen

Incomplete hemispherical irradiation of the sample (or collection of radiation, in the reverse geometry) in an integrating sphere reflectometer is unavoidable due to sample viewing (or illumination) requirements. This means that one measures with nearly

Specular Baffle for Improved Infrared Integrating Sphere Performance.

November 1, 2003

Author(s)

Leonard M. Hanssen, A Prokhorov, V B. Khromchenko

Baffles are often placed in integrating spheres to accommodate the non-ideal aspects of other sphere components. These include detectors, sources, sphere wall surface shape and coatings. Baffles intentionally prevent light interchange between these and

Calibration of a Spectral Responsivity Transfer Standard

September 1, 2003

Author(s)

George P. Eppeldauer, Leonard M. Hanssen

Algorithmic Model of Microfacet BRDF for Monte Carlo Calculation of Optical Radiation Transfer

August 1, 2003

Author(s)

A Prokhorov, Leonard Hanssen

An algorithmic model of bi-directional reflectance distribution function (BRDF) based on the ray optics approximation and microfacet model of randomly rough surface is proposed. Its central idea is that for every incident ray, the normal vector to the

Monte Carlo Modeling of an Integrating Sphere Reflectometer

July 1, 2003

Author(s)

A Prokhorov, Sergey Mekhontsev, Leonard Hanssen

The Monte Carlo method has been applied to numerical modeling of an integrating sphere designed for hemispherical-directional reflectance factor measurements. It is shown that a conventional algorithm of inverse ray tracing used for estimation of

Algorithmic Model of Microfacet BRDF For Monte Carlo Calculation of Optical Radiation Transfer

January 1, 2003

Author(s)

Leonard M. Hanssen, Alexander Prokhorov

Emissivity Modeling of Thermal Radiation Sources With Concentric Grooves

January 1, 2003

Author(s)

Leonard M. Hanssen, Sergey Mekhontsev, Alexander Prokhorov

Evaluation of Performance of Integrating Spheres For Indirect Emittance Measurement, ed. by B. Fellmuth, J. Seidel, and G. Scholz

January 1, 2003

Author(s)

Leonard M. Hanssen, Sergey Mekhontsev, Alexander Prokhorov

Fourier Transform System for Characterization of Infrared Spectral Emittance of Materials, ed. by B. Fellmuth, J. Seidel, and G. Scholz

January 1, 2003

Author(s)

Leonard M. Hanssen, Simon G. Kaplan, Sergey Mekhontsev

Linearity Characterization of NIST's Infrared Regular Transmittance and Reflectance Scales

January 1, 2003

Author(s)

Leonard M. Hanssen, Simon G. Kaplan

Linearity Characterization of NIST's Infrared Spectral Regular Transmittance and Reflectance Scales

January 1, 2003

Author(s)

Leonard M. Hanssen, Simon G. Kaplan

System Linearity is a fundamental characterization performed on spectrophotometers. Yet it is one that is not adequately performed on Fourier transform instruments, because of the lack of a method for linearity characterization that will work sufficiently