Reliability of 1.8-meter solar radio telescope at Metsähovi Radio Observatory for long-term solar monitoring

Our aim is to prove that long time series of solar observations measured with Metsähovi Radio Observatory's 1.8-meter solar radio telescope, RT-1.8, at 11.2 GHz are reliable, and that the data can be used for solar cyclicity studies. We give a detailed description of RT-1.8 and its calibration. We compare 14 years of Metsähovi Radio Observatory's solar data from solar cycles 23 and 24 to both Dominion Radio Astrophysical Observatory (DRAO 2015), Penticton, Canada 2.8 GHz and Nobeyama Solar Radio Observatory (NSRO 2015), Nobeyama, Japan 9.4 and 17.0 GHz data. Our results show high correlation between all data sets.