Reception of ELF transmitter signals at Moshiri, Japan, and their propagation characteristics

Measurements are described of 82 Hz radio signals arriving from the Russian ELF transmitter located on the Kola Peninsula, Russia. We used two orthogonal calibrated horizontal magnetic field sensors and a vertical electric antenna at the Moshiri observatory, Hokkaido (geographic coordinates; 44.4 degrees N, 142.2 degrees E). Several propagation characteristics were studied: (1) signal amplitude and its variations on diurnal and seasonal scales, (2) phase difference between the two horizontal magnetic field components (wave polarization), and (3) wave arrival angle. The amplitude detected was compared with early published data, showing a good agreement. We estimated the source current moment of the transmitter by comparing our experimental amplitude with theoretical computations. This 82 Hz signal field is found to be linearly polarized, which allowed for the goniometric finding of source bearing. The arrival azimuth is consistent with the geometry of the experiment.