Research on Real Time Single-Station GNSS PWV Monitoring Method and Experimental Verification at Sea

Ground-based GNSS PWV has been operationalized utilizing abundant historical radiosonde (RS) observations. However, in ocean areas, especially in the open sea, there is a lacking of RS observations which results rare research on GNSS PWV monitoring method at sea. Moreover, Network solution of GNSS PWV is difficult to achieve at sea due to extremely limited communication bandwidth on offshore observation platforms, which makes single-station GNSS PWV monitoring more suitable for this type of application scenario. In this paper, a real time single-station GNSS PWV monitoring method is proposed based on real-time precise point positioning (RT-PPP) exploiting BD3 PPP-B2b precise point positioning service signal and weighted average temperature <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{T}_{\mathbf{m}})$</tex> model established by regression using ERA5 reanalysis data. To evaluate the accuracy of this method, an experimental system has been implemented at coastal station in Qingdao. The results show that compared with RS PWV monitoring data from a nearby radiosonde station, the RMSE of the proposed method is 1.51mm, which proves that this method is applicable for real-time tropospheric PWV monitoring at sea.