23 rd Cycle of Solar Activity in the Light of 34 Years of Cracow Observations of Solar Radio Emission

Systematic daily observations of solar radio emission were started at the Fort Skała Observatory on 1st October 1957. The observations were made at the frequency of 810 MHz first with a 5m radio telescope - and since 1964 with a 7m one; at present they comprise already almost 70 thousand hours of observations (Michalec 1991). During that period there were two longer interruptions in the observations: from 23 September 1963 to 2 February 1964 - due to transferring the radio telescope’s antenna from the top of the Fort to a new site, and from 6 November 1973 to 11 March 1974 - connected with the reconstruction of the receiver. Other, fortunately short, interruptions in the course of observations had no influence on the homogeneity of the series.