A Ground-based GNSS-R Marine Environment Dynamic Monitoring Station

Global navigation satellite system-reflectometry (GNSS-R) is considered a promising technology for monitoring marine environments. However, there is still a lack of GNSS-R stations that provide comprehensive data. For this reason, a stationary marine information dynamic monitoring platform using GNSS-R method was constructed in Weihai City, Shandong Province, China. This station consists of two antennas, an intermediate frequency (IF) data collector, a wind sensor and a laptop computer with GPUs. The up-looking antenna is used for direct signal receiving and the down-looking antenna serves for reflected signals. The wind sensor records wind speed and wind direction simultaneously at 1Hz. The collector can export IF data with 62MHz sampling rate which covers signals including GPS L1/L5, BDS B1I/B1C/B2a and Galileo E1/ E5a. The laptop with self-developed software defined receiver (SDR) is employed for processing large amounts of IF data and outputting sea surface height observations based on dual-antennas method in real-time. In the preliminary study, the results based on code-delay method show that the accuracy of BDS B2a can realize centimeter altimetry after post-processing while the accuracy of GPS L5 is approximately in the decimeter range due to the limited number of satellites within the visible range. Additionally, these observations can be also used to retrieve wind speed. We look forward to more research on GNSS-R in the future, for which we can provide data collected by this GNSS-R station.