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Optical Radiation Group

The Optical Radiation Group maintains, improves, and disseminates the national scales for the candela (SI unit), spectral responsivity, reflectance, transmission, color, and appearance.

Our staff participates in national and international committees and intercomparisons to ensure the acceptance of US radiometric, photometric, colormetric, and spectrophotometric standards and measurements. We also develop protocols for the calibration and validation of optical remote sensing instruments, perform long-term research, and maintain the infrastructure necessary to ensure the advancement of radiometry, photometry, colorimetry, and spectrophotometry measurement technology.

News and Updates

Projects and Programs

Spectral responsivity measurement

NIST provides calibration of the spectral responsivity and spatial uniformity of photodetectors for use in industrial and government labs. These calibrations

Color and appearance

We are developing instrumentation, standards artifacts, and measurement protocols to characterize appearance attributes including color, texture, and gloss

Photometry

The purpose of photometry is to measure light in a way that takes the sensitivity of human visual system into account. While radiometry measures light in all

Publications

A review of protocols for Fiducial Reference Measurements of water-leaving radiance for validation of satellite remote sensing data over water

Author(s)
Kevin Ruddick, Emmanuel Boss, Alexandre Castagna, Robert Frouin, Alex Gilerson, Martin Hieronymi, Bettye C. Johnson, Joel Kuusk, Zhongping Lee, Michael Ondrusek, Viktor Vabson, Riho Vendt, Kenneth Voss, Giuseppe Zibordi
This paper reviews the state of the art of protocols for measurement of water-leaving radiance in the context of Fiducial Reference Measurements (FRM) of water

A review of protocols for Fiducial Reference Measurements of downwelling irradiance for validation of satellite remote sensing data over water

Author(s)
Kevin Ruddick, Andrew Banks, Emmanuel Boss, Alexandre Castagna, Robert Frouin, Martin Hieronymi, Cedric Jamet, Bettye C. Johnson, Zhongping Lee, Michael Ondrusek, Viktor Vabson, Riho Vendt, Kenneth Voss, Giuseppe Zibordi
This paper reviews the state of the art of protocols for measurement of downwelling irradiance in the context of Fiducial Reference Measurements (FRM) of water

Tools and Instruments

Spectrally tunable lighting facility

Solid-state lighting (SSL) is increasingly being introduced into the market and it is expected that many of the light sources currently used for general

Aperture area measurement facility

NIST has established an absolute aperture area measurement facility for circular and near-circular apertures use in radiometric instruments. The facility

Spectral comparator facilities

Visible to near-infrared spectral comparator facility (Vis/NIR SCF) The Vis/NIR SCF is a monochromator-based system that typically measures the spectral power

Reference 0:45 reflectometer

The primary purpose of the 0:45 reflectometer is to disseminate color standards to the color and appearance community. The instrument was designed to provide

Contacts

Group Leader

Office Manager