Abstract: A wireless local messaging system includes a transmitter transmitting a local message to a navigation receiver configured to receive and process navigation messages from satellites of a global navigation satellite system on a given carrier frequency, each of the satellites transmitting the navigation messages with a satellite-individual PRN code. The transmitter transmits the local message in a local message signal on the given carrier frequency with a local PRN code that is not used by a satellite of the global navigation satellite system, and the receiver receives the local PRN code and processes the local message signal.

Abstract: A near field navigation system is equipped with a base segment provided on a base structure. The base segment includes at least four transmitters. Each transmitter is provided with a base antenna and the base antennas are positioned relative to each other at known distances. A user segment is provided on a user structure, the user segment including at least one receiver, at least one user antenna connected to the receiver, and a processing unit connected to the receiver. The receiver and each of the transmitters together form distance measuring units and the processing unit is adapted to calculate the relative three-dimensional position data of the user structure with respect to the base structure on the basis of distance data obtained from the distance measuring units.

Abstract: A wireless local messaging system includes a transmitter transmitting a local message to a navigation receiver configured to receive and process navigation messages from satellites of a global navigation satellite system on a given carrier frequency, each of the satellites transmitting the navigation messages with a satellite-individual PRN code. The transmitter transmits the local message in a local message signal on the given carrier frequency with a local PRN code that is not used by a satellite of the global navigation satellite system, and the receiver receives the local PRN code and processes the local message signal.

Abstract: A near field navigation system is equipped with a base segment provided on a base structure. The base segment includes at least four transmitters. Each transmitter is provided with a base antenna and the base antennas are positioned relative to each other at known distances. A user segment is provided on a user structure, the user segment including at least one receiver, at least one user antenna connected to the receiver, and a processing unit connected to the receiver. The receiver and each of the transmitters together form distance measuring units and the processing unit is adapted to calculate the relative three-dimensional position data of the user structure with respect to the base structure on the basis of distance data obtained from the distance measuring units.