Analysis of ionospheric scintillation spectra and TEC in the Chinese low latitude region

Abstract

GPS L-band scintillations and total electron content (TEC) were recorded at Sanya (18.33 • N, 109.52• E) during the period July 2004-July 2005. Automatic recorded raw digital scintillation data are analyzed to obtain the spectral characteristics of irregularities producing ionospheric scintillations and to estimate the correlation between amplitude scintillation and power spectral density. Concurrent measurements of TEC are used to analyze ROTI, defined as the standard deviation of the rate of change of TEC. The statistical results of S4 indices and power spectral indices indicate that the power spectral indices increase with S4 indices for weak scintillation (0.1 ≤ S4 < 0.3), but for moderate and strong scintillation, spectral indices tend to be saturated. In the analyzed data set, the ratio of ROTI/S4 is found to vary between 0.3 and 6, and the variation in estimated zonal drift velocities during geomagnetic quiet days (K p < 3) shows that the motion of the irregularities is highly variable in the initial phase of irregularity development. After about 22:00 LT, the estimated drift velocities tend to follow the same pattern.

Statistical characteristics of low-latitude ionospheric scintillation over China

“…On the other hand, earlier drift measurements of irregularities producing GPS ionospheric scintillations over Sanya were estimated from the scintillation spectra by using a single receiver (e.g., Li et al, 2007b). To improve the quality of drift measurements, another GPS receiver was installed in July 2007 over Sanya.…”

A study of GPS ionospheric scintillations observed at Shenzhen

“…These studies show that scintillation activity varies with geographical location, local time (LT), season and magnetic activity. Li et al (2007) used the scintillation data recorded at Sanya (18.33°N, 109.52°E) from July 2004-July 2005 to obtain the spectral characteristics of irregularities producing ionospheric scintillations and to estimate the correlation between amplitude scintillation and power spectral density. Deng et al (2013) statistically analysed the variations of the scintillation with the local time, season, solar activity and duration of scintillation patches using the observation data collected at Guangzhou (23.…”

Ionospheric scintillation monitoring at a low latitude Indian station during geo-magnetic storm

“…The power spectral densities (PSD) of amplitude and phase can be calculated during the scintillation events and the PSD of amplitude and phase will obey the power-law given by, (5) where f is frequency in Hz, T is a strength parameter, and n is the slope which is a unit less quantity. The spectral slope n is calculated using least mean square method by finding the best fit to the slope portion of the spectrum and increases with scintillation intensity [6].…”

“…The analysis has been done with the help of power spectral density calculations to understand the variation of electron density irregularities [6,7]. Amplitude scintillations will cause loss of lock of GPS signal as carrier-to-noise ratio (ClNo) degrades during moderate and severe scintillation events [8,9].…”