A regional GPS receiver network for monitoring equatorial scintillation and total electron content

Abstract

Abstract. A network of Global Positioning System (GPS) single-frequency (L1) receivers has been installed in Australia and Southeast Asia for the purpose of monitoring equatorial ionospheric scintillation during the current peak in solar cycle activity. Dual-frequency receivers to measure total electron content are also operating at some stations and will be described in a later paper. With respect to equatorial scintillation our long-term intention is to characterize its statistical properties and its effect on GPS link performance within the Asian-Australian longitude zone (approximately from 100 ø to 150 ø E) as a function of time of day, season, sunspot number, and magnetic latitude, for comparison with available models such as WBMOD and in order to quantify the potential for navigational degradation, especially during times of elevated solar activity. In this paper, the scintillation receiver network is described, and preliminary results are presented from the first two years of operation (1998 and 1999). Our initial results include measurements of diurnal and seasonal variations in $4 and an analysis of the performance of multiple satellite links which indicates that just prior to solar maximum, GPS can approach marginal performance because of scintillation.

Latitudinal and temporal variation of equatorial ionospheric irregularities determined from GPS scintillation observations

“…We have assumed that there is a high degree of correlation of scintillation occurrence over longitude, not only across the field of view at each site, but also over the region in general. This is validated by the results of Thomas et al (2001) and is due to the very small magnetic declination angle over the region.…”

“…The ISMs are based on Novatel 951 GPS single frequency (L1) receivers which have been modified to process raw data sampled at 50 Hz and calculate various parameters which characterise the observed scintillation. The ISMs are stationed at 6 separate locations in the SouthEast Asian region, a detailed description of the the network is given by Thomas et al (2001). Briefly, Fig.…”

Seasonal modulation of GPS performance due to equatorial scintillation

“…The 6 stations of the network [ Thomas et al , 2001] monitor an extended geographic area (see Table 1). Data gathering commenced at Parepare, Pontianak and Marak Parak in December 1997, at Darwin in June 1998, at Vanimo in August 1999 and at Fang in June 2000.…”

Research of Ionospheric Scintillation in Asia (RISA)

“…In a modeling study of B-1B and F-15E weapons platforms, Evans (2005)demonstrated that scintillation degrades accuracy and can, if occurring in conjunction with jamming, render GPS unavailable. In the intervening years since Thomas et al (2001), more has been learned about scintillation and GPS. Thomas' original exploration and particular presentation, however, was never expanded to include other sites or years.…”