First experience on spatial discrimination of large-scale natural elf interference on the example of two-point measurements of the magnetic field of an artificial ionospheric source

We present the results of an experiment on the generation of extremely low-frequency (ELF) electromagnetic fields at frequencies near the first Schumann resonance upon the ionosphere modification by modulated powerful radio emission. The reception was performed at two sites spaced by 14 km in the distance from “SURA” facility. It was found that the natural noise at different reception sites is highly correlated, which allows one to achieve the noise suppression by about an order of magnitude by subtracting the measurement results. We demonstrate the opportunities of spatial discrimination of the interference upon the two-site reception of the “small-scale” field of an artificial ionospheric source. The directions of future studies and possible applications are discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radio.zika, Vol. 49, No. 12, pp. 1030–1042, December 2006.