Instruments and Methods for the Ground-Level Reference Measurement of Solar Radiation, Albedo and Net Radiation

Abstract

Regular actinometrical observations in Tartu Actinometric Station started in 1950. Since 1954, it has been regarded as one of the most effectively working actinometric station in the Soviet Union. In 1965, the station was moved, and it is now located at Tõravere, about 20 km southwest from Tartu, on the territory of Tartu Observatory (φ =58°16′, λ =26°28′). The station currently belongs to the Estonian Meteorological and Hydrological Institute, but is working under the supervision and with the collaboration of scientists from the Tartu Observatory (former Institute of Astrophysics and Atmospheric Physics). Right from the start of scientific activities, methodical investigations to improve the accuracy of the measurements were initiated. Investigations have proceeded continuously, albeit with variable intensity, and encompassed a very wide range of problems: instrumental and methodical errors, comparison between different sensors, calibration of the instruments, designing new instruments, etc. In the former Soviet Union and Eastern European countries, instruments manufactured in the Soviet Union were in use as a rule. After the breaking up of the Soviet system, the modernization of the equipment to meet worldwide standards was started in these countries.