Jonathan Jones is a senior scientist at the Met Office, working in the Observations R&D Department since 2002. Jonathan's research interests relate to the derivation of tropospheric and ionospheric observations from GNSS signals, receiving his PhD in the field from the University of Nottingham in 2010. Jonathan has been involved in many European collaborative GNSS projects, recent roles include: Chair of COST Action ES1206 GNSS4SWEC (2013-2017), Chair of the EIG EUMETNET E-GVAP Processing and Standards Working Group and co-Chair of the GCOS Reference Upper Air Network (GRUAN) GNSS Precipitable Water Vapour Task Team. He is a member of many scientific working groups such as the IGS Tropospheric Working Group, IAG Working Group 4.3.3, EPOS WG4 and GAIA-CLIM WP2, is a Fellow of the Royal Meteorological Society and an editor of the ACP/AMT/ANGEO inter-journal Special Issue on Advanced GNSS Tropospheric Products for Severe Weather Events and Climate. Guergana Guerova is an associate professor at the Department of Meteorology and Geophysics of Sofia University. She received her Master's degree in meteorology and PhD in Applied Physics from the University of Bern. She is a former Marie Curie IRG Fellow (2011-2014) and vice chair of COST Action ES1206 GNSS4SWEC (2013-2017). Her research interest include monitoring short and long-term variation of GNSS derived water vapour, especially for studying fog, intense precipitation, hail storms and heat waves. She teaches courses at both the undergraduate (Introduction to Meteorology part 1, Synoptic Analysis) and graduate (Satellite Imagery Interpretation) level. Jan Dousa is a senior researcher at the Research Institute of Geodesy, Topography and Cartography (RIGTC) - Geodetic Observatory Pecný (GOP), Czech Republic, where he is leading GNSS group. He obtained a PhD degree at the Department of Advanced Geodesy, Czech Technical University in Prague in 1999. He participated in several international projects dealing with ground-based GNSS tropospheric research, such as COST 716, TOUGH, E-GVAP, Trop4LAS, DARTMA, COST 1206, IGS Tropo WG, and he led others with a national support. His interests are in advanced methods of precise GNSS processing, with a particular focus on reference frames (EUREF), precise GNSS orbit determination (IGS), troposphere monitoring (E-GVAP, GNSS4SWEC), GNSS in solid earth sciences (EPOS) and software development (G-Nut). Dr Dousa was chair of Working Group 1 in the GNSS4SWEC COST project, chair or vice-chair of several IAG working groups, member of the EUREF Governing Board and ESA GNSS Scientific Advisory Board, and associate member of the International GNSS Service. Galina Dick is a senior scientist at the German Research Centre for Geosciences GFZ in Potsdam, where she has been responsible for the ground-based GNSS atmospheric sounding since 2000 and became a group leadership of "GNSS Meteorology" in 2017. She has been involved in many European GNSS meteorology projects since 1999, like the COST Action 716 "Exploitation of ground-based GPS for climate and numerical weather prediction applications" and the European Commission's TOUGH project "Targeting Optimal Use of GPS Humidity Measurements in Meteorology". She is head of the GFZ GNSS Analysis Centre for the EUMETNET EIG GNSS Water Vapour Programme (E-GVAP). Within GRUAN - The Global Climate Observing System (GCOS) Reference Upper-Air Network - she is responsible for GNSS Data Processing Centre. She is an associate member of the International GNSS Service (IGS), a member of the IGS troposphere working group, as well as a member of several expert teams and working groups dealing with GNSS-derived precipitable water vapour. Within COST Action GNSS4SWEC she was a co-chair of the Working Group 1: "Advanced Processing Techniques". Siebren de Haan is a senior researcher at the Research and Development Observations and Data Technology department, KNMI. Siebren holds a degree in mathematics and completed his PhD in meteorology at the University of Wageningen in May 2008. He worked for two years on the assimilation of satellite derived sea surface temperatures for use in numerical weather prediction models and on an ice detection algorithm using backscatter data from the ERS satellites at the EUMETSAT Ocean and Sea Ice Satellite Application Facility. He is currently involved in the EUMETNET GPS Water Vapour Programme (E-GVAP I-III) and the EUMETNET ASIST programme, and is a member of the WMO CIMO Expert Team on New Technologies and Test Beds and WMO CIMO Task Team on Aircraft-based Observations. His latest activities are related to novel wind and temperature observations from commercial aircraft exploiting Mode-S Enhanced Surveillance information. Eric Pottiaux started working at the Royal Observatory of Belgium (ROB) in 1998 to study the Earth's neutral atmosphere using GNSS, and received his PhD degree from the Université Catholique de Louvain (UCL) in 2010. From 1999 to 2006 he took part in the COST Action 716 "Exploitation of ground-based GPS for climate and numerical weather prediction applications" and contributed to the European Commission's TOUGH project "Targeting Optimal Use of GPS Humidity Measurements in Meteorology". Today, he is a geodetic expert in the EUMETNET EIG GNSS Water Vapour Program (E-GVAP) and a member of the IGS troposphere WG, co-founder of the COST Action ES1206 GNSS4SWEC, and vice-chair of IAG WG 4.3.7 "Real-time GNSS Troposphere Monitoring" and IAG WG 4.3.8 "GNSS Tropospheric Products for Climate". Olivier Bock is a senior researcher in Geodesy at IPGP - IGN. He holds a PhD in Remote Sensing and Physics of the Environment from the Université Paris Diderot and a postdoctoral degree ("habilitation") in Physics of the Environment from the Université Pierre et Marie Curie, Paris. His research interests are in thestudy of the global atmospheric water cycle with applications in meteorology and climatology using atmospheric models and GNSS and other measurement techniques. He was a former Chair of Working Group 3 of the COST Action ES1206 GNSS4SWEC aiming at the development of climate monitoring using GNSS data. He is the author or co-author of more than 70 publications in international peer-reviewed scientific journals and has been a guest editor of the inter-journal Special Issue on Advanced GNSS Tropospheric Products for Severe Weather Events and Climate in ACP/AMT/ANGEO. Rosa Pacione began her career with space geodesy activities financed by the Italian Space Agency, first with Telespazio S.p.A and later with e-GEOS S.p.A. She is currently supervising the geodetic data analysis activities performed in the framework of the ASI contract to operate the ASI Centro di Geodesia Spaziale, Matera (Italy). She has been involved in European GNSS meteorology projects since 1999. Her currentresearch interests are in GNSS meteorology and the development of GNSS products for climate monitoring and related applications. Dr Pacione has substantial international experience as a member of several international boards including the EUREF Governing Board. She is also the EPN Tropospheric Coordinator, a member of the E-GVAP Processing and Standards WG and IGS Tropospheric WG, co-founder of the COST Action ES1206, chair of IAG WG 4.3.8 "GNSS Tropospheric Products for Climate", and convener at the EGU General Assembly. Roeland Van Malderen is work leader at the Royal Meteorological Institute of Belgium's scientific division "Observations", which he entered in 2006. He obtained his PhD in Mathematics (Astronomy) from the Catholic University of Leuven (Belgium) in 2003 and subsequently worked for two years as a Hydrologist-Modeller at the Flemish Administration for Environment, Nature, Land and Water Management. His current research interests are in data quality assessment, data uncertainty estimation and data homogenization to study the variation in data series due to climate change processes. Dr Van Malderen is particularly interested in the variation of water vapour and ozone, both the total column values (e.g. retrieved by GNSS for water vapour) and the vertical profiles (from radio and ozone soundings). He recently joined the board of associate editors for the journal Atmospheric Measurement Techniques (AMT).
