Abstract: A navigation system for an enclosed area, the navigation system comprising: a) at least one satellite signal receiving station, positioned outside the enclosed area, to receive satellite signals transmitted by a constellation of satellites and to determine time synchronization information relative to the transmitted signals; b) at least one local transmitting station, positioned within the enclosed area, to transmit a local signal compatible with the transmitted satellite signals; and c) a communication channel to communicate self-alignment information between each station and at least one other station; wherein each local transmitting station uses the self-alignment information to generate the local signal; and wherein the at least one local signal provides navigation information useable by a satellite navigation receiver.

Abstract: A navigation system for an enclosed area, the navigation system comprising: a) at least one satellite signal receiving station, positioned outside the enclosed area, to receive satellite signals transmitted by a constellation of satellites and to determine time synchronization information relative to the transmitted signals; b) at least one local transmitting station, positioned within the enclosed area, to transmit a local signal compatible with the transmitted satellite signals; and c) a communication channel to communicate self-alignment information between each station and at least one other station; wherein each local transmitting station uses the self-alignment information to generate the local signal; and wherein the at least one local signal provides navigation information useable by a satellite navigation receiver.