Global effects on Ionospheric Weather over the Indian subcontinent at Sunrise and Sunset
- S. N. Bose National Centre for Basic Sciences, JD Block, Salt-Lake, Kolkata-700098 (India)
Study of Very Low Frequency (VLF) electromagnetic wave is very important for knowing the behavior of the Ionospheric layers due to Sunrise-Sunset, Earthquakes, Solar flares, Solar eclipses and other terrestrial and extra terrestrial radiations. We study the properties of the variation of the VLF signal strength theoretically all over Indian sub-continent. As an example, we concentrate on the VLF signal transmitted by Indian Naval Transmitter VTX at Vijayanarayanam (Latitude 08 deg. 23', Longitude 77 deg. 45') near the southern tip of Indian subcontinent. As has been noticed, several receiving stations placed during the VLF campaign in all over India, the VLF signal strength varies significantly with place and time. To understand the diurnal and seasonal variation of the received signal, a complete knowledge of physics of intensity distribution of the VLF signal is essential. The spatial variation of VLF signal plays an important role in selecting future VLF stations. In the wave-hop theoretical model presented here, horizontally stratified ionospheric layers have been considered. The VLF wave emitted by the transmitter has both the ground wave and the sky wave components. The ground wave attenuates during propagation. The sky wave component experiences reflections by the ionosphere on its way to the receiver and its attenuation depends on the degree of ionization. Intensity variation occurs at a given receiver location for interference among singly and multiply reflected waves. This has been simulated considering some simplified and justifiable assumptions. This spatial variation wave-hop theoretical model developed here has been compared with LWPC code generated results.
- OSTI ID:
- 21428646
- Journal Information:
- AIP Conference Proceedings, Vol. 1286, Issue 1; Conference: 1. international conference on science with very low frequency radio waves: Theory and observations, Kolkata (India), 13-18 Mar 2010; Other Information: DOI: 10.1063/1.3512875; (c) 2010 American Institute of Physics; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COSMOLOGY AND ASTRONOMY
ATTENUATION
COMPUTERIZED SIMULATION
EARTHQUAKES
ECLIPSE
ELECTROMAGNETIC RADIATION
INDIA
INTERFERENCE
IONIZATION
IONOSPHERE
REFLECTION
SEASONAL VARIATIONS
SOLAR FLARES
ASIA
DEVELOPING COUNTRIES
EARTH ATMOSPHERE
RADIATIONS
SEISMIC EVENTS
SIMULATION
SOLAR ACTIVITY
STELLAR ACTIVITY
STELLAR FLARES
VARIATIONS