The Optical Thermometry and Spectral Methods Group (844.03) maintains, improves, and disseminates the national scales for the spectroradiometric measurement of radiation sources and temperatures. Provides visible and ultraviolet spectrophotometry research and standards in reflectance, transmission, color, and appearance. Participates in national and international committees and intercomparisons to insure the acceptance of US radiometric, radiance temperature, and spectrophotometric standards and measurements. Develops protocols for the calibration and validation of optical remote sensing instruments. Performs long-term research and maintains the infrastructure necessary to insure the advancement of optical thermometry, radiometry, and spectrophotometry measurement technology.