Abstract: The invention relates to a base station for a real-time kinematic (RTK) positioning system with one or more rover units and/or an RTK positioning system and/or a method for calibrating a base station and/or a method for operating an RTK positioning system. The base station comprises a global navigation satellite system (GNSS) receiver, a transmission device for transmitting correction data to the one or more rover units, a wireless LAN (WLAN) module, and at least one control unit, wherein the at least one control unit is adapted to operate the base station in a rover mode comprising receiving correction data from a Networked Transport of RTCM via Internet Protocol (NTRIP) server and determining two or more rover mode positions of the base station based on the received NTRIP correction data, and wherein the at least one control unit is adapted to determine an optimized position of the base station by averaging the rover mode positions.