A comparative study of VLF signals from several transmitters around the world as observed from Maitri station, Antarctica

摘要

To examine the behavior of the sunrise and sunset terminators, characteristics of the solar activities in the polar region and the possible seismic correlation with ionospheric anomalies a Stanford AWESOME VLF receiving system was installed at the Indian permanent Antarctic station Maitri during the 27th Indian scientific expedition to Antarctica. Almost five weeks of data was recorded successfully from several transmitters around the globe. The narrow-band signals show variation of the solar radiation and the signature of the prolonged day and night. We compare the signal of frequency 18.2 kHz with the same signal received at Kolkata and we present simultaneous observation of the variation of the sunrise and sunset terminators.We compare the diurnal signal amplitude variation with the LWPC model. We also present the broadband signal, contains the signature of sferics. The signals do not have a strong signature of whistlers because at the conjugate points, the lightning effects are minimum.