2 separate dipole antennas) [@Gorgutsa2001];

-   CALLISTO BIR (location: Birr, Ireland; coords: $\phi_0 = 53.094^\circ$, $\lambda_0 = -7.92^\circ$; frequency band: 10-105 MHz; aerial: bicone antenna);

-   CALLISTO BLENSW (location: Bleien, Switzerland; coords: $\phi_0 = 47.34^\circ$, $\lambda_0 = 8.112^\circ$; frequency band: 8-79.6 MHz; aerial: bicone antenna);

-   CALLISTO DARO (location: Dingden, Germany; coords: $\phi_0 = 51.77^\circ$, $\lambda_0 = 6.623^\circ$; frequency band: 20-80 MHz; aerial: tilted terminated folded dipole antenna);

-   CALLISTO ESSEN (location: Essen, Germany; coords: $\phi_0 = 51.394^\circ$, $\lambda_0 = 6.979^\circ$; frequency band: 30-90 MHz; aerial: bicone antenna);

-   CALLISTO GLASGOW (location: Glasgow, Scotland; coords: $\phi_0 = 55.902^\circ$, $\lambda_0 = -4.307^\circ$; frequency band: 45-80.8 MHz; aerial: log-periodic dipole array antenna).

The NDA and the URAN-2 are phased arrays which have automatic solar tracking systems. The angular sizes of the NDA and the URAN-2 antenna patterns are about $6^\circ\times10^\circ$ and $3.5^\circ\times7^\circ$, correspondingly, at 25 MHz. The IZMIRAN’s dish antenna and separate dipoles also track the Sun. They are regularly pointed with steering commands from an observer. The beam width of the 10-meter dish is near $20^\circ$ within the 90-270 MHz range, while dipoles, running in 25-50 MHz and 45-90 MHz bands, have beam width about $40^\circ$. The above-listed CALLISTO devices (spectrometer 