New sensor for study of ULF magnetic activity

Ultra low frequency (ULF) variations (0.001-3 Hz) of natural magnetic field are very important for ground study of magnetospheric and ionospheric magnetohydrodynamic waves and solar-terrestrial interaction. Besides it a lithospheric ULF magnetic activity is recently considered as very promising candidate for application to short-time earthquake (EQ) forecasting. Present progress in spectral analysis methods and data processing instrumentation allows studying of signal fine structure almost in real-time operation condition, which is of great importance, particularly, for short-time prediction problem. Usually the lithospheric ULF EQ magnetic precursors are much weaker than magnetospheric signals and their frequency ranges are completely overlapped.