Radiometric standards in the USSR

Primary radiometric standards of incoherent radiationin the 0.04-25 micron range, developed and maintained in the USSR, are described. The standards are based on a synchrotron radiation source, high- and low-temperature blackbodies and absolute radiometer. The basic characteristics of the standards are given and the prospects for the construction of the cryogenic blackbody and absolute radiometer to be used for low-intensity calibrations are discussed. The methods and calibration systems for aerospace instrument calibrations against the radiometric standards are mentioned.