{"title":"Sudden amplitude and phase changes in subionospheric VLF transmitter signals observed at Agra, India","authors":"Vikram Singh, Shikha Agrawal, Birbal Singh","doi":"10.1541/JAE.30.53","DOIUrl":null,"url":null,"abstract":"The amplitude and phase of VLF transmitter signals NWC (19.8 kHz), NPM (21.4 kHz), and NAA (24 kHz) have been monitored at Agra (geomag. lat. 17.10°N, L=1.15), India using AbsPAL receiver for a period of three years between 01 September, 2002 and 30 August, 2005. Seven cases of abrupt amplitude and phase changes have been identified which varied between 3 and 7 dB and 40° and 80° respectively. The onset duration varied around 5 sec. The observed characteristics have been examined in the light of lightning induced electron precipitation (LEP), solar flares, and lightning, and finally attributed to early/slow perturbation caused by distant sprites and lightning along the propagation paths.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"17 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of atmospheric electricity","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1541/JAE.30.53","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
The amplitude and phase of VLF transmitter signals NWC (19.8 kHz), NPM (21.4 kHz), and NAA (24 kHz) have been monitored at Agra (geomag. lat. 17.10°N, L=1.15), India using AbsPAL receiver for a period of three years between 01 September, 2002 and 30 August, 2005. Seven cases of abrupt amplitude and phase changes have been identified which varied between 3 and 7 dB and 40° and 80° respectively. The onset duration varied around 5 sec. The observed characteristics have been examined in the light of lightning induced electron precipitation (LEP), solar flares, and lightning, and finally attributed to early/slow perturbation caused by distant sprites and lightning along the propagation paths.