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Comparison study of amplitude scintillation between GNSS and satellite beacon receivers in Thailand
(2022-01-01)
Seechai, Khanitin
;
Myint, Lin Min Min
;
Hozumi, Kornyanat
;
Supnithi, Pornchai
Ionospheric scintillation is caused by irregular electron density in the ionosphere. Severe ionospheric scintillation can degrade the Global Navigation Satellite System (GNSS) signal quality and system performance. In low-latitude region, the phenomenon that may cause the ionospheric scintillation, called equatorial plasma bubble or EPB frequently arise. The effects of EPB on the scintillation at different frequencies and systems need to be analyzed as the study will enhance our EPB understandings. In this work, we aim to study the relationship of the amplitude scintillation index between from GNSS and satellites beacon receivers at KMITL, Thailand to determine the size and characteristics of EPB. The GNSS data were collected in March, April, September, and October 2021. From the analysis, the results show that during locally disturbed time, satellite beacon signals complement the GNSS signals to indicate EPB occurrences.
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Statistical Analysis of Scintillation Index and ROTI based on Multi-GNSS Data at Chumphon, Thailand
(2021-06-27)
Seechai, Khanitin
;
Jamjareegulgarn, Punyawi
;
Wang, Ningbo
;
Supnithi, Pornchai
Ionospheric scintillation is caused by the fluctuation of electron density in the ionosphere. Severe ionospheric scintillation can degrade the Global Navigation Satellite System (GNSS) signal quality and performance. In low-latitude region, the phenomenon that may cause the ionospheric scintillation, called equatorial plasma bubble or EPB frequently arise. Rate of TEC change Index (ROTI) is utilized to detect the EPB occurrence. In this work, we aim to determine the relationship between the amplitude scintillation index (S4) and the rate of TEC change index (ROTI) at Chumphon, Thailand. The data are collected from a multi-constellation multifrequency GNSS receiver from 11 November to 31 December 2020. From the analysis, the results show that the percentage of enhanced ROTI and S4 events are 21.57% and 17.65%, respectively. Moreover, the statistical number of simultaneous enhancements of ROTI and S4 show the good correspondence. Refer to GALILEO and BeiDou, the S4 index of low frequency signal is disturbed more frequently than that of high frequency signal. However, this phenomenon cannot be seen in GPS.
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Performance of M-PSK in mobile satellite communication over combined ionospheric scintillation and flat fading channels with MRC diversity
(2009-07-01)
Supnithi, Pornchai
;
Wongtrairat, Wannaree
;
Tantaratana, Sawasd
Combined scintillation and terrestrial fadings occur in mobile satellite communication channels as the signal passes through the ionosphere and the lower atmosphere. This results in a product fading channel, which negatively affects the performance of the system. The challenge is to evaluate the performance of the system, in terms of the average bit error probability (BEP). In this paper, through the use of the moment generating function, we derive expressions for the average BEP and an upper bound for M-ary phase-shift keying (M-PSK) modulation with maximal-ratio combining (MRC) diversity over the product Rician x Rician channel. The results are expressed as double summations in terms of the generalized hypergeometric function, which can be computed using standard commercial software. For a large Rician factor, the expression is simplified to a single summation. Numerical results are obtained from the derived expressions and compared with simulation results. They show very good agreement for various Rician factors and the number of diversity branches. The upper bound is also evaluated and shown to be reasonably tight. © 2009 IEEE.
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The analysis of ionospheric scintillation on the global Positioning System (GPS) at Bangkok
(2006-12-01)
Theerapatpaiboon, P.
;
Supnithi, P.
;
Leelaruji, N.
;
Hemmakorn, N.
This paper presents analysis of ionospheric scintillation on GPS signal (1575.45 MHz) by using the GSV4000 GPS receiver installed at KMITL. The characteristic of ionospheric scintillation on GPS signal are analyzed by employing S<inf>4</inf> index to identify the amplitude scintillation and σ<inf>ø</inf>(60 sec) to identify the phase scintillation, From the results, we found that the ionospheric scintillation phenomena impact on the GPS signal leading to the error in the global positioning system, differ from the non-scintillation period more than 20 meters. © 2006 ICASE.
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The effects of sumatra-andaman earthquake on total ionospheric electron content (TEC) and ionospheric scintillation of GPS signal in thailand
(2005-12-01)
Theerapatpaiboon, P.
;
Leelaruji, N.
;
Hemmakorn, N.
;
Supnithi, P.
This paper presents the effects of Sumatra-Andaman earthquake (26 December 2004) on the total ionospheric electron content (TEC) by using the TEC Meter (JAVAD) installed at KMITL. From the results, we found that the total ionospheric electron content enhancement at the time of this earthquake is higher than other days about 7 TEC units. Furthermore, the study includes the effect of this phenomenon on GPS signal (1575.45 MHz) by employing S<inf>4</inf> index and σ<inf>φ</inf> (60sec) to identify the severity of amplitude scintillation and phase scintillation, respectively. From the observation, we can conclude that TEC variation is the cause of ionospheric scintillation leading to the position error on GPS about 8 meters. © 2005 IEEE.

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