Abstract: A method for providing authenticated correction information, in particular orbit, clock and bias/offset correction information, to a mobile receiver in a GNS system, including: receiving raw data from satellites at a plurality of reference stations; forwarding the raw data received at the reference stations to a central computation unit, in particular to a single central computation unit, using a data stream, in particular a common data stream; determining the correction information at the computation unit based on the raw data received from the different reference stations and transmitting the correction information via at least one satellite to the receiver for reliably determining a position of the mobile receiver.