Investigation of ionospheric scintillation effects on BDS precise point positioning at low-latitude regions

We present a study on the effects of ionospheric scintillation on BeiDou Navigation Satellite System (BDS) precise point positioning (PPP) at low-latitude regions. The analysis was carried out using BDS data collected by a newly installed ionospheric scintillation monitoring receiver located at Sha Tin of Hong Kong and 15 Hong Kong Satellite Positioning Reference Station Network (SatRef) stations from October 6, 2015, to November 17, 2015. The rate of total electron content index (ROTI) derived from BDS data is shown to be a good indicator in observing the ionospheric scintillation. The analysis indicates that the correlation coefficient between ROTI and S4/σφis about 0.7. Under scintillation activity, the time series of positioning results for BDS static PPP show a stable variation, but the irregularities are reflected in the time series of code and phase residuals with the maximum values as 7.096 and − 0.469 m, respectively. Further, under scintillation condition it is found that positioning results for BDS kinematic PPP vary significantly and the range can reach several meters in the east, north and up directions. The statistical results show that the three-dimensional root-mean-square of BDS PPP is 1.842 m under scintillation condition, which is much larger than that for non-scintillation condition as 0.155 m.