Real-time Monitoring Regional Ionospheric Variety of China with BDS Observations

BDS provides uninterrupted PNT service for Asia-Pacific area since 27 December 2012, when China released an official version of the complete BDS Interface Control Document (ICD) for open service Signal-In-Space (SIS). Because BDS signals working at three frequencies, ionospheric delay can be calculated with pseudo-range dual-frequency combination technique and a new technique to monitor ionospheric variety over China is established. Lower-middle latitude area of China is in the ionospheric equator anomalies region and large grads ionospheric varieties often occur within the area of north latitude 20°±5°. Daily variety characteristic of ionospheric delay measured with BDS GEO satellites is analyzed by using BDS real-time pseudo-range observation and adopting carrier phase smoothed pseudo-range. China region ionospheric map is painted in 1°×1° scale with polyhedral fitting every 5 minutes and the average fitting error RMS of all Ionospheric Punch Point (IPPs) is 2.778TECU. The ionospheric anomalies around China monitored with BDS observation shows that the VTEC peak difference between adjacent two days can be 60TECU when large scale ionospheric anomaly occurs.