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

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)