A comparative study of the sunrise and sunset effects on the integrated field intensity of VLF atmospherics
A comparative study is made of the stepped structure of atmospherics during sunrise and sunset hours at three harmonically related frequencies in the VLF band, observed at the coast of the Bay of Bengal. The occurrences of the steps, their duration, time sequence and amplitudes are critically ex...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
1995-09-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/13/976/1995/angeo-13-976-1995.pdf |
| Summary: | A comparative study is made of the stepped
structure of atmospherics during sunrise and sunset hours at three harmonically
related frequencies in the VLF band, observed at the coast of the Bay of Bengal.
The occurrences of the steps, their duration, time sequence and amplitudes are
critically examined. Our analysis reveals that the start times of the third and
second steps of the sunrise effect are always before ground sunrise, while the
start of the main step is distributed on both sides of it. During sunset hours,
the onset time of the main step is before the local ground sunset, but for the
second and third steps, the onset times are after that. The results are
interpreted by considering the multi-hop propagation as well as the distributed
noise sources surrounding the observing site. |
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| ISSN: | 0992-7689 1432-0576 |