Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat
Solar flare is one of the main phenomena of space weather that has affected technologies such as radio communication, satellite systems and power grid operations. The interaction process has led to the variations of frequencies which can be observed from the ground station. This research focuses...
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| Format: | Thesis |
| Language: | English |
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2018
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| Online Access: | http://ir.uitm.edu.my/id/eprint/26969/ http://ir.uitm.edu.my/id/eprint/26969/1/TP_AFIFAH%20TAAT%20EE%2018_5.pdf |
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uitm-269692019-12-27T05:09:18Z http://ir.uitm.edu.my/id/eprint/26969/ Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat TaaT, Afifah Electronics Nuclear engineering. Atomic power Solar flare is one of the main phenomena of space weather that has affected technologies such as radio communication, satellite systems and power grid operations. The interaction process has led to the variations of frequencies which can be observed from the ground station. This research focuses mainly on low frequencies which are Very Low Frequency (VLF) and Ultra-Low Frequency (ULF) within the range of 3 - 30kHz and 1.7-500 mHz respectively. The affected frequency variations were observed during quiet (Q-day) and flare (F-day) day of solar cycle 24. The recorded data of the VLF and ULF signals were extracted from the Atmospheric Weather Electromagnetic System for Observation Modelling and Education (AWESOME) located at Universiti Kebangsaan Malaysia (UKM) and the Magnetic Data Acquisition System (MAGDAS) respectively. Previous researchers have demonstrated the affected frequencies mainly due to geomagnetic storms instead of solar flare events and separately discussed between the frequencies. In contrast, the new method of analysis due to solar flare events at lowlatitude region was presented in this research. The combination investigation and observation have been done for both VLF and ULF signals. The modeling of Long Wave Propagation Capability (LWPC) code and International Reference Ionosphere Model (IRI2016) were applied to generate the values of Ne (electron density, m־ᶟ), H7(VLF reflection height parameter, km) and β (exponential sharpness factor, km־¹). In addition to that, the geomagnetic field components (H and Z) were calculated to observe the correlation of ULF variations associated with solar flare events. In the analysis, the diurnal variations of VLF and ULF signals have been observed. Q-day was selected to measure the Average Amplitude Difference (AAD) for ULF while the method of Average Percentage Difference (APD) has been used for VLF signal during daytime and nighttime for three (3) different transmitter stations which are NWC/19.8kHz, JJI/ 22.2kHz, and DHO/23.4kHz.All the transmitters had different latitudes and distances from the receiver stations (UKM) and propagated within the Earth-ionosphere waveguide (EIWG). It is found that, the NWC signal had lower APD which was 7.72% as compared to JJI (10.14%) and DHO (15.4%). For further investigation on lowfrequency signals (VLF and ULF), the affected amplitude (AA) due to solar flares demonstrated different classes of solar fluxes which are C, M, and X-Class. The correlation coefficient (r) of mathematical analysis was used to measure the correlation between the solar x-ray fluxes (X, M, and C-class) and ionospheric parameters. Statistical results showed that the propagation distance between transmitter and receiver has contributed on the affected frequency variations (VLF). For ULF, three difference relationship have been approached which are the intensity of solar flares, local time dependence and location of solar flares on Sun's surface. The result shows the affected of low-frequency signals has been correlated with the intensity of solar flares and dependent to the occurrence of solar flares. At the end of this research, the characterization of the low-frequency signals was presented as an indicator to morphological regularities of low frequency (VLF and ULF) variations with respect to solar flare events at low latitude regions. 2018 Thesis NonPeerReviewed text en http://ir.uitm.edu.my/id/eprint/26969/1/TP_AFIFAH%20TAAT%20EE%2018_5.pdf TaaT, Afifah (2018) Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat. PhD thesis, Universiti Teknologi MARA. |
| repository_type |
Digital Repository |
| institution_category |
Local University |
| institution |
Universiti Teknologi MARA |
| building |
UiTM Institutional Repository |
| collection |
Online Access |
| language |
English |
| topic |
Electronics Nuclear engineering. Atomic power |
| spellingShingle |
Electronics Nuclear engineering. Atomic power TaaT, Afifah Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat |
| description |
Solar flare is one of the main phenomena of space weather that has affected technologies
such as radio communication, satellite systems and power grid operations. The
interaction process has led to the variations of frequencies which can be observed from
the ground station. This research focuses mainly on low frequencies which are Very Low
Frequency (VLF) and Ultra-Low Frequency (ULF) within the range of 3 - 30kHz and
1.7-500 mHz respectively. The affected frequency variations were observed during quiet
(Q-day) and flare (F-day) day of solar cycle 24. The recorded data of the VLF and ULF
signals were extracted from the Atmospheric Weather Electromagnetic System for
Observation Modelling and Education (AWESOME) located at Universiti Kebangsaan
Malaysia (UKM) and the Magnetic Data Acquisition System (MAGDAS) respectively.
Previous researchers have demonstrated the affected frequencies mainly due to
geomagnetic storms instead of solar flare events and separately discussed between the
frequencies. In contrast, the new method of analysis due to solar flare events at lowlatitude
region was presented in this research. The combination investigation and
observation have been done for both VLF and ULF signals. The modeling of Long Wave
Propagation Capability (LWPC) code and International Reference Ionosphere Model
(IRI2016) were applied to generate the values of Ne (electron density, m־ᶟ), H7(VLF
reflection height parameter, km) and β (exponential sharpness factor, km־¹). In addition
to that, the geomagnetic field components (H and Z) were calculated to observe the
correlation of ULF variations associated with solar flare events. In the analysis, the
diurnal variations of VLF and ULF signals have been observed. Q-day was selected to
measure the Average Amplitude Difference (AAD) for ULF while the method of
Average Percentage Difference (APD) has been used for VLF signal during daytime and
nighttime for three (3) different transmitter stations which are NWC/19.8kHz, JJI/
22.2kHz, and DHO/23.4kHz.All the transmitters had different latitudes and distances
from the receiver stations (UKM) and propagated within the Earth-ionosphere
waveguide (EIWG). It is found that, the NWC signal had lower APD which was 7.72%
as compared to JJI (10.14%) and DHO (15.4%). For further investigation on lowfrequency
signals (VLF and ULF), the affected amplitude (AA) due to solar flares
demonstrated different classes of solar fluxes which are C, M, and X-Class. The
correlation coefficient (r) of mathematical analysis was used to measure the correlation
between the solar x-ray fluxes (X, M, and C-class) and ionospheric parameters. Statistical
results showed that the propagation distance between transmitter and receiver has
contributed on the affected frequency variations (VLF). For ULF, three difference
relationship have been approached which are the intensity of solar flares, local time
dependence and location of solar flares on Sun's surface. The result shows the affected
of low-frequency signals has been correlated with the intensity of solar flares and
dependent to the occurrence of solar flares. At the end of this research, the
characterization of the low-frequency signals was presented as an indicator to
morphological regularities of low frequency (VLF and ULF) variations with respect to
solar flare events at low latitude regions. |
| format |
Thesis |
| author |
TaaT, Afifah |
| author_facet |
TaaT, Afifah |
| author_sort |
TaaT, Afifah |
| title |
Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat |
| title_short |
Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat |
| title_full |
Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat |
| title_fullStr |
Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat |
| title_full_unstemmed |
Morphological regularities of low-frequency signal due to solar flare events at low-latitude region / Afifah Taat |
| title_sort |
morphological regularities of low-frequency signal due to solar flare events at low-latitude region / afifah taat |
| publishDate |
2018 |
| url |
http://ir.uitm.edu.my/id/eprint/26969/ http://ir.uitm.edu.my/id/eprint/26969/1/TP_AFIFAH%20TAAT%20EE%2018_5.pdf |
| first_indexed |
2023-09-18T23:17:38Z |
| last_indexed |
2023-09-18T23:17:38Z |
| _version_ |
1777419218842550272 |