An analysis of low-latitude ionospheric scintillation and its effects on precise point positioning

摘要

Global Positioning System (GPS) receivers at low latitudes have a high probability of experiencing severe ionospheric scintillations. This paper presents the results of scintillation characteristics and scintillation effect on GPS precise point positioning (PPP), using the data observed by the first ever GNSS scintillation monitoring receiver in Hong Kong. Ionospheric scintillation data were collected in July and August 2012 using a Septentrio PolaRxS Pro receiver located at a station (22°12′N, 114°15′E) in the south of Hong Kong. It was observed that August had much more and stronger scintillations than July in Hong Kong. Amplitude scintillation events ( 4 S ≥0.4) were frequently observed during 21:00-3:00 LT (UT+8 hour) in July and 20:00- 4:00 LT in August. Strong scintillations ( 4 S ≥0.8 or 0.8 rad ) were mostly observed during 0:00-1:00 LT in July and 20:00-23:00 LT in August. The effect of scintillations on GPS positioning was evaluated using a dual-frequency PPP method. It revealed that under the impact of severe ionospheric scintillations ( 4 S ≥1.0 and ≥1.0 rad), the largest PPP error can increase to more than 34 cm in the vertical and more than 20 cm in the horizontal components.