Characteristics Analysis for the Spherical Antenna of a Seismometer
A seismometer for vertical electric field component of natural ELF and ULF electromagnetic waves measurement by using spherical antenna is introduced. The goal of the proposed seismometer is to provide continuous observation of the natural electromagnetic emissions related to the coupling of seismic activity with the outer spaces and ionosphere, which utilize a spherical aluminum electrode 78mm in diameter with embedded enhanced preamplifier circuits that built to mount flush with the ground so as to preserve the configuration in which the antenna operates. The presented seismometer has a wide frequency response at low frequencies, it's typical sensitivity in the frequency range DC to 30MHz are shown to be and ,the dynamical range is >50dB in ELF and VLF and about 25dB in HF.
Zhihua Xu, Gang Shen and Sally Lin
H. M. Yu "Characteristics Analysis for the Spherical Antenna of a Seismometer", Advanced Materials Research, Vols. 171-172, pp. 458-461, 2011