Anyone with a roof can join.

Geodnet

Geodnet is a public blockchain-based and token-incentivized network of GNSS reference stations. The reference stations monitor space weather (ionosphere, troposphere) as well as GNSS satellite clock and orbit signals. The reference station data is used for RTK and precise positioning of GNSS receivers to centimeter accuracy. Stations also collect precise geospatial which monitors geodetic changes such as Earthquakes, Structural Deformation, and other Geohazards. Finally the trusted global grid of stations can either produce or validate other sensor data such as Environmental Sensing.