Near real-time GNSS processing at GOP in support of meteorology

Since 1999, GOP has been estimating zenith total delays (ZTD) using GPS data permanent stations in testing near real-time (hourly) mode. This product is design for the support of numerical weather forecasting. Since 2001 the product has been routinely uploaded to the UK MetOffice server. This activity has contributed to the following projects: COST-716, TOUGH, E-GVAP I-III and GNSS4SWEC (COST ES1206). Since 2006 and 2008, GOP products are operationally assimilated into numerical weather forecasting models in UK MetOffice and MeteoFrance, respectively.

In 2008, GOP initially implemented and assessed results from near real-time stand-alone GLONASS solution using ultra-rapid GLONASS orbits (also developed at GOP, Dousa 2009). Tropospheric products were compared with stand-alone GPS and combined GPS+GLONASS solutions. Since 2011, GOP produces operationally GPS + GLONASS solution and deliver it to the E-GVAP project.

In 2010, GOP developed the first global hourly GNSS estimates that were assessed within a 10-month period (Dousa and Bennitt, 2008 GPS Sol). Since 2011, it has became part of GOP delivery to E-GVAP and tropospheric parameters are operationally assimilated into global UK MetOffice and MeteoFrance models.

In 2012, GOP implemented the first real-time solution based on its own software G-Nut/Tefnut using Precise Point Positioning method and global precise products from the International GNSS Service (IGS). The product was assessed using 1-year period of routine run for 18 European and 18 global GNSS stations (Dousa and Vaclavovic, 2014). Since 2014, GOP real-time solution have included also GLONASS data and estimation of tropospheric horizontal gradients.