رسالة جامعية
Analysing transient effects in the ionosphere using narrowband VLF data.
| العنوان: | Analysing transient effects in the ionosphere using narrowband VLF data. |
|---|---|
| المؤلفون: | Bremner, Sherry. |
| مرشدي الرسالة: | Collier, Andrew B. |
| سنة النشر: | 2009 |
| المجموعة: | South African National ETD Portal |
| مصطلحات موضوعية: | VLF radio wave propagation., Ionosphere, Radio wave propagation., Theses, Physics. |
| الوصف: | Very Low Frequency (VLF) radio waves propagate within the Earth-ionosphere waveguide with very little attenuation. Modifications of the waveguide geometry affect the propagation conditions, and hence, the amplitude and phase of VLF signals. Changes in the ionosphere, such as the presence of the D-region during the day, or the precipitation of energetic particles, are the main causes of this modification. Using narrowband receivers monitoring remote VLF transmitters, the amplitude and phase of these signals are recorded. A multivariate data analysis technique, Principal Component Analysis (PCA), is applied to the data in order to determine parameters such as seasonal and diurnal changes which affect the variation of these signals. Data was then analysed for effects from extragalactic gamma ray bursts, terrestrial gamma ray flashes and solar flares. Only X-rays from solar flares were shown to have an appreciable affect on ionospheric propagation. Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009. |
| Original Identifier: | oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/8323Test |
| نوع الوثيقة: | Thesis |
| الإتاحة: | http://hdl.handle.net/10413/8323Test |
| رقم الانضمام: | edsndl.netd.ac.za.oai.union.ndltd.org.ukzn.oai.http...researchspace.ukzn.ac.za.10413.8323 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
| الوصف غير متاح. |