BeiDou Signal Parameters Characterization During Strong Equatorial Ionospheric Scintillation

Abstract

Following China’s establishment of the BeiDou navigation satellite test system in 2000, BeiDou has become an important member of the GNSS family with its steady schedule of satellite launches towards the plan of becoming a full global constellation by 2020. Ionospheric monitoring and space weather studies greatly benefit from the increasing number of available BeiDou signals with an improved spatial coverage of observations. It is well known that strong ionospheric scintillation over equatorial regions is characterized by the simultaneous presence of deep signal amplitude fading and random carrier phase fluctuations, which may degrade GNSS receiver carrier tracking performance. Many studies have been conducted on characterizing ionospheric scintillation on GPS signals. However, there has been a lack of studies on BeiDou signal ionospheric scintillation characteristics. In this paper, real BeiDou B1 scintillation data collected during an experimental campaign in March 2013 at an equatorial site, Ascension Island, was processed to investigate fast phase variations concurrent with deep amplitude fading on B1 signals. A semi-open loop algorithm was applied to improve the carrier phase estimation during deep fades. The results reveal half and full cycle carrier phase changes occurring concurrently with deep fades, as has been previously reported on GPS L1 and L5 signals. From studies of nearly 300 fades, which occurred during 83 minutes of strong scintillation, phase change duration distributions and associated deep fading characteristics were obtained and then compared with those previously obtained from L1 signals in the GPS data collected during the same campaign. Keywords: BeiDou Signal; Ionospheric Scintillation; Deep fading and sudden phase changes.