Some known Reference Networks

RINEX data from CORS (Continuously Operating Reference Stations) can also be used for GeoTagz in lieu of your base station. Find a reference station with a baseline of 10km or less from your flight to ensure high position accuracy for PPK results. At distances greather than 10km, your accuracy will degrade, and you may be required to use your local base station.

Many countries operate CORS networks and make their RINEX data available for download. Where possible, use a base station that provides both GPS and Glonass data at a high recroding rate - ideally 1s. You can find a non-exhaustive list of some popular reference networks below. Some are free while others charge for service.