Preliminary study on loss of lock of satellite signal at the mid-latitude region in China

The phenomenon of loss of lock of satellite signal at the middle latitude region is firstly presented by using a ground-based GNSS ionospheric TEC and scintillation receiver (Weihai, China) 122.296°E, 36.866°N, during a period of 2018−2019. Based on our proposed criterion to filtering out loss of lock of satellite signal, a couple of classical loss of lock events have been shown. Moreover, the possible reasons to inducing them are then analyzed by using the global TEC data obtained from the madrigal database. The preliminary results suggest that the loss of lock phenomenon obtained by the ground-based receiver can still happen even during periods of low solar activities at middle latitudes of China. Furthermore, the duration of loss of lock cases varies from 1 minute to more than 10 minutes. Additionally, before and after the event of loss of lock, the signal-to-noise ratio (SNR) and scintillation indices are often strongly fluctuating. Regarding the possible generation reason, the rapid decrease of plasma density (or TEC) of the ionosphere are possibly associated with the loss of lock. Consequently, this study firstly investigates the loss of lock at middle-latitude regions in China through a ground-based GNSS receiver, extending our knowledge on this harmful phenomenon and suggesting the potential application value.