European Space Agency (ESA)
Programmes: QA4EO
Former Programmes: IDEAS+ ; Soil Moisture and Ocean Salinity (SMOS); Sensor Performance, Products, Algorithms (SPPA)
Contact: Roberto Sabia, Philippe Goryl, Susanne Mecklenburg
Website: http://www.esa.int
Task: Financial support of design, implementation, and operation
Global Terrestrial Network on Hydrology (GTN-H)
Contact: Stephan Dietrich
Website: www.gtn-h.info
Task: International coordination with hydrological observation networks
Global Climate Observing System (GCOS)
Panel: Terrestrial Observation Panel for Climate (GCOS-TOPC)
Contact: Wolfgang Wagner
Website: https://public.wmo.int/en/programmes/global-climate-observing-system
Task: International coordination with climate observation community
Comitee on Earth Observation Satellites (CEOS)
Group: Land Product Validation team for soil moisture
Contact: Michael Cosh, Carsten Montzka 
Website: https://ceos.org/
Task: Coordination with satellite soil moisture validation community and algorithm developers
Group on Earth Observations (GEO)
Theme: Integrated Global Water Cycle Observations (IGWCO), Task WA-08-01a (Soil moisture)  
Website: https://earthobservations.org/index.php
Task: Integration of data hosting facility in global water cycle observing system
Global Energy and Water Exchange Project (GEWEX)
Working Group: International Soil Moisture Working Group
Contact: Peter van Oevelen
Website: http://www.gewex.org
Task: International coordination with climate modelling community