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Spectral Responsivity Determination of a Transfer-Standard Pyroelectric Radiometer



George P. Eppeldauer, J Racz, Leonard M. Hanssen


A NIST-Developed pryoelectric radiometer was characterized and calibrated to extend the NIST high accuracy spectral responsively scale from the visible range to the ultraviolet (UV) and infrared (IR). The transmission of the gold-black coated LiNbO3 pyroelectric material is negligibly small, therefore the absorptance, equal to (1-reflectance), is proportional to the responsivity of the detector. The spectral total reflectance of the coating was measured with integrating spheres and spectrophotometers to determine the relative spectral responsivity from the UV to the IR. The relative spectral responsivity was converted into absolute spectral power and irradiance responsivities by measuring the total power in a 442 nm stabilized laser beam. The reference device for absolute calibraton was a Si trap-detector calibrated against the primary standard cryogenic radiometer. The calibrations were repeated with 31 months separation. A 0.3% long-term shift in the reflectance was measured between 800 nm and 19 m. the 28% reflectance at 10.6 m scaled up the 0.1% spatial responsivity non-uniformity in the visible (where the reflectance was 0.4%) to 8%. The spectral power and irradiance responsivity scales of the pyroelectric radiometer have been realized between 250 nm and 2.5 m with a relative standard uncertainty of less than 0.34% (coverage factor k=1).
Proceedings Title
Infared Spaceborne Remote Sensing, Conference | 10th | Infared Spaceborne Remote Sensing X | SPIE
Conference Dates
July 7-11, 2002
Conference Title
Proceedings of SPIE--the International Society for Optical Engineering


absolute responsivity, gold-black coating, infrared, irradiance, pyroelectric detector, radiant power, radiometer, reflectance, relative response


Eppeldauer, G. , Racz, J. and Hanssen, L. (2002), Spectral Responsivity Determination of a Transfer-Standard Pyroelectric Radiometer, Infared Spaceborne Remote Sensing, Conference | 10th | Infared Spaceborne Remote Sensing X | SPIE (Accessed June 22, 2024)


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Created December 1, 2002, Updated February 17, 2017