Simulating siberian radioheliograph response to the quiet Sun

The Siberian Radioheliograph (SRH) correlation plot is the time dependence of the sum of absolute values of complex correlations over all baselines. These plots are built for each operating frequency of SRH. The correlation is related not only to the spatial coherence of the incident microwave emission but also to antenna gains. That is why we have to consider real SRH antenna gains and shadowings. Correlation plots obtained by SRH are related to microwave flux density of the Sun and spatial features of microwave sources. Also the correlation plots show variability of SRH beam pattern in time with constant flux density and spatial structure of sources. The SRH beam pattern depends on position of the Sun with respect to SRH, which changes with time. This leads to variations of these plots, which can be confused, for example, with the quasi-harmonic oscillations of the microwave flux produced by sources located above sunspots. Because the solar disk is an extended source, the correlation plot variability is mostly due to the SRH response to the quiet Sun...