The solar radio noise is measured daily with amateur instrumentation, theat means I use an old communication receiver AR3000 modified
for radio astronomy purposes. The detector is composed of an analoge multiplier S042P (Siemens). The Yagi-antenna is a standard TV antennae (BIV/V)  for channel 37.
The antennae is fixed in meridian, but the elevation is  tilted once or twice per month according to the actual elevation of the suns orbit (Transit Meridian Instrument).
The receiver is programmable via RS232 with a Windows compatible PC running under XP and Borland Builder 6. This PC is also part of
my internal network, thus the data can be captured very easily. Every month a graph and a listing will be produced and stored in the archive below.

• Archiv 2000: Listings and Graphs for every month
• Archiv 2001: Listings and Graphs for every month
• Archiv 2002: Listings and Graphs for every month
• Archiv 2003: Listings and Graphs for every month
• Archiv 2004: Listings and Graphs for every month
• Archiv 2005: Listings and Graphs for every month
• Archiv 2006: Listings and Graphs for every month
• Archiv 2007: Listings and Graphs for every month
• Archiv 2008: Listings and Graphs for every month
• Archiv 2009: Listings and Graphs for every month
• Archiv 2010: Listings and Graphs for every month
• Archiv 2011: Listings and Graphs for every month
• Archiv 2012: Listings and Graphs for every month

• Overview solar cycle at 230 MHz measured in Freienbach [15 years from 1982 - 1997] (23 KB)
• Overview solar cycle at 470 MHz measured in Freienbach [16 years from 1984 - 2000] (20 KB)
• Overview solar cycle at 610 MHz measured in Freienbach [13 years from 1997 - 2010] (21 KB)

Single frequency light curve AR3000. The graph above shows the actual received signal presented in degree Kelvin absolut aequivalent antenna noise temperature. Every measurement-point is individually calibrated under software control with a semiconductor  noise source in the frontend box (focal plane unit). Calibration takes place automatically twice per minute, for equations see tables below. The plott is updated automatically every couple of minute.

Multi frequency light curves produced by Callisto Non calibrated data during transit of the sun. Dynamic solar spectra are stored in FIT-files Access to documents and data here.

	Top: LCD-screen showing sun passage in Math-CAD Mid left: Power supply 12V Mid mid: DCF77-receiver supplying 1MHz clock, Computer mouse Mid right: e-Callisto Radiospectrometer 45MHz...870MHz Keyboard Receiver AR3000, Quadratic detector (S042P) and attenuator -10dB Integrator 6.8msec is also in the blue box Personal Computer Windows XP
	Top left: Preamplifier KUHNE +20dB, 5MHz....1500MHz Top right: SPDT Daico (selection between calibration or antenna) Centre: Noise source and 2 attenuators 23dB in total Right: Calibration SPDT (selection between noise source or T0) Bottom: cables from antenna and to receiver as well as some control cables
	Yagi antenna for channel 36 (WIPIC) pointing to the transit position of the sun

Tant = antenna temperature [Kelvin] Tcold = reference temperature = 273.15Kelvin + measured ambient temperature [°C] Thot = noise source temperature = 701Kelvin Ihot = measured digits when the noise source is applied Icold = measured digits when the termination resistor having ambient temperature is applied Iant = measured digits when the antenna is switched on while pointing to the sky or to the sun

S = solar flux expressed in sfu where 1sfu = 10^(-22) W/m^2/Hz = 10'000FU = 10'000Jansky Tant = antenna temperature, see above pi = 3.1416,  k = Boltzman constant = 1.38E-23 J/K G = antenna gain in the order of 14dB +/- 0.6dB lambda = wavelength = 49.18cm at 610MHz r/R = correction factor of sun distance to the earth (one number per month)

Shown left the home brewed analysis software tool. Every data set of each day is read into the plot window (white dots)  and then Fourier-transformed. All higher frequencies are set to zero and the residual spectrum is then Fourier-transformed back into the time-domain, see yellow plot. By this way we get a kind of filter function. The plot between the two green vertical lines are analyzed by reading minimum and maximum values. This difference is presented as DeltaT (Antenna temperature of the sun). This temperature difference (sun-background) is then multiplied by some system parameters to get the solar radio flux, see equations above.