1. WG1: ASYM subgroup
Overview of recent activities of the contributors and future plans:
AUSTRIA (Gregor Möller, Robert Weber, TU Vienna)
- Effect of the GNSS processing strategy (PPP vs. DD)
 anisotropic tropo. effects recovered from double differenced post-fit residuals
 tropospheric effects absorbed by other parameters
- Cleaning of the zero-differenced post-fit residuals
- Contribution to STD validation BENCH (Napeos, PPP, GMF, ZTD every 30 min & GRD every 1h)
- plot / compare results (ZTD, Gradients, STD, DDR, PZDR, PSDR)
BELGIUM (Eric Pottiaux, ROB)
- Contribution to STD validation BENCH (4 data sets using Bernese 5.2, PPP, ZTD every 15 min & GRD every 1h)
° GMF + no residuals
° GMF + residuals (every 30s)
° VMF + no residuals
° VMF + residuals (every 30s)
BELGIUM (Hugues Brenot, BIRA)
- Contribution to STD validation BENCH (simulation from ALADIN-CZ outputs)
 simulation of ZTD, GRD, and STD from ALADIN-CZ outputs
 quantification of delays induce by hydrometeors
- Development of tools to visualise STD/SIWV from obs. & NWM

2. WG1: ASYM subgroup
Overview of recent activities of the contributors and future plans:
CZECH REPUBLIC (Jan Douša, Pavel Vaclavovic, GOP)
- Contribution to defined TroSINEX slant delay format
- Implementation prototype of TroSINEX encoder in G-Nut/Tefnut
- Development of slant delay retrievals in G-Nut/Tefnut applying various solutions for real-time (forward filter), post-
processing (backward smoother) and NRT (filter+smoother)
- Contribution to STD validation BENCH (using G-Nut/Tefnut, ZTD every 30 min & GRD every 1h)
- Development of tropospheric gradient estimations (RT,NRT,PP)
- Assessment of tropospheric gradients - GNSS Repro2 and ERA-Interim
CZECH REPUBLIC (Michal Kačmařík, TUO)
- Contribution to STD validation BENCH (using Bernese, PPP, VMF1, ZTD every 30 min & GRD every 1h)
- Statistical results for STD validation
FRANCE (Laurent Morel et al., CNAM/ESGT)
- Contribution to STD validation BENCH (using GAMIT, DD, VMF1, ZTD every 30 min & GRD every 1h)
GERMANY (Galina Dick, Florian Zus., GFZ)
- Contribution to STD validation BENCH (using EPOS, PPP, VMF1, ZTD every 15 min & GRD every 1h)
- Contribution to STD validation BENCH (simulations from ERA-Interim, NCEP GFS outputs)
POLAND (Jan Kaplon, WUELS)