Abstract

Reliable, long-term, radiometric calibration of space-based instruments for the study of extreme-ultraviolet (EUV) radiation, nominally 10 to 120 nm, has not been achieved in the past (Neupert 1986). Solar EUV observations have depended upon periodic recalibrations with rocket-borne instruments, but the data have been subject to adjustments and, as a consequence, criticisms (Lean 1987). Other astrophysical studies at EUV wavelengths have frequently used white dwarfs as standards, but the observed spectra are model-dependent. EUV radiometric fidelity requires in-orbit irradiance standards that can be used to monitor changes in the detection sensitivity of sun-observing and astronomical EUV spectrometers.

© 1988 Optical Society of America