Absolute Flux Calibration of Stars; Calibration of the Reference Telescope
Allan W. Smith, John T. Woodward IV, Colleen A. Jenkins, Steven W. Brown, Keith R. Lykke
Absolute stellar photometry is based on 1970s terrestrial measurements of the star Vega with instruments calibrated using the Planckian radiance from a Cu fixed-point blackbody. Significant advances in absolute radiometry have been made in the last 30 years that offer the potential to improve both terrestrial and space-based absolute stellar photometry. These advances include the development of detector-based radiometry utilizing spectrally tunable laser sources and improved atmospheric transmittance modelling and characterization. We describe the applications of these new technologies for ground-based spectral irradiance measurements of standard stars at wavelengths ranging from 0.35 mm to 1.7 mm.