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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

Shrinking (Ultra)Violet

While awaiting full access to their labs due to COVID-19 restrictions, scientists at the National Institute of Standards and Technology (NIST) have taken this

Universe in the Balance

Researchers at the National Institute of Standards and Technology (NIST) have found a way to link measurements made by a device integral to microchip

Projects and Programs

Diffraction effects in radiometry

We want to quantify the breakdown of geometrical optics when computing the throughput of optical systems for the purpose of calculating "diffraction corrections

Radiation Thermometry

Calibration standards for radiation thermometry are disseminated in the form of radiation thermometers, tungsten strip lamps and blackbodies. These disseminated

Spectral responsivity measurement

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

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

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

Contacts

Group Leader

Office Manager