| Name | Type | Country | Components |
|---|---|---|---|
| Ukkel | Observational platform | Belgium | 1 |
| UNIAQ/CETEMPS | Observational platform | Italy | 2 |
| University Innsbruck (UIBK) | Observational platform | Austria | 1 |
| University Vienna (UNIVIE) | Observational platform | Austria | 1 |
| Unmanned Aerial vehicle (UAV) | Mobile platform | Finland | 2 |
| Unmanned Systems Research Laboratory (USRL) | Mobile platform | Cyprus | 1 |
| Utö Atmospheric and Marine Research Station | Observational platform | Finland | 1 |
| Vielsalm | Observational platform | Belgium | 2 |
| Villum Research Station | Observational platform | Denmark | 1 |
| Waldhof | Observational platform | Germany | 2 |
