Measurement of vertical electric field using a borehole antenna
A borehole antenna of 120 m height has been installed at our Bichpuri , Agra campus in rural area about 12 Km west of Agra city to reduce electric and electromagnetic disturbances. The induced voltages in the antenna are amplified, filtered at the VLF frequency of 3 kHz, peak detected, and recorded on a DC ink chart recorder. Now the analog recording has been replaced by digital recording using PCL 206 ADC and LABTECH software.. A terrestrial vertical antenna of 20 m height is also operated in conjunction with the borehole antenna for the study of Lithosphere- Atmosphere coupling of the Seismo-electromagnetic signals. The results have shown large enhancements in the occurrence of signal bursts prior to Chamoli and other earthquakes. A block diagram of the experimental; arrangement is shown below.
Experimental arrangements for monitoring vertical electric field component of the seismo-electricfield emissions at Agra