RADIOMETRY WITH CRYOGENIC RADIOMETERS AND SEMICONDUCTOR PHOTODIODES

The paper reviews some of the advances in optical radiation measuremen ts made over the last twenty years, particularly through the use of cr yogenic radiometers and solid-state detector transfer standards. The w ay in which base scales of many optical radiation measurements are lin ked and the prospects for a further improvement in accuracy, particula rly by the measurement of sources using well-characterized filter radi ometers, are discussed.