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: In a method for reducing the adverse effect of clock frequency jumps on a user-position determination device in a global navigation system, a plurality of space vehicles each having a clock, transmit position determination information to the position determining device. If a sufficient number of such navigation signals from a first group of space vehicles having clocks in which no jump occurs are available for this purpose, and if a calculated integrity risk is acceptable, position determination is performed using those navigation signals. If not, however, the position determination device receives navigation signals from space vehicles of a second group with clocks in which jumps can occur. The latter signals are combined with signals from the first group in a manner which takes into account possible jumps, and the process is repeated.

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: For amending navigation data of a global navigation system, navigation signals are received from a space vehicle, and a predicted clock phase offset of the clock signal sent from the space vehicle is estimated and stored in a memory. The clock phase offset difference between the current estimated clock phase offset and a previously estimated clock phase offset times (T1) is then computed and stored. An earlier computed phase offset difference between a previously estimated clock phase offset and a further previous estimation for said clock phase offset is obtained, wherein the time interval between the current measurement epoch and second earlier epoch is at least T1. The difference between the computed clock phase offset differences is derived, and compared with a given threshold value. If the latter difference is greater than the given threshold value, an integrity risk signal is generated and transmitted to other devices for position determination.

Abstract: In a method for providing integrity information for users of a global navigation system, which comprises several space vehicles like satellites transmitting information to a device for position detection, the transmitted information comprises first information from the global navigation system about the accuracy of a signal in space error SISE of a faulty space vehicle, and second information whether or not the global navigation system assesses the faulty space vehicle as faulty. The invention is based on the assumption how exact a fault can be detected, so that performance the global navigation system can be increased; and no unfounded assumption is used which improves the quality of service.

Abstract: A method for detecting frequency jumps of a navigation satellite's master clock, comprising the steps of i) monitoring the master clock signal that is generated by a master clock onboard of the satellite for a frequency jump, and ii) signaling a detected frequency jump of the master clock signal.

Abstract: For amending navigation data of a global navigation system, navigation signals are received from a space vehicle, and a predicted clock phase offset of the clock signal sent from the space vehicle is estimated and stored in a memory. The clock phase offset difference between the current estimated clock phase offset and a previously estimated clock phase offset times (T1) is then computed and stored. An earlier computed phase offset difference between a previously estimated clock phase offset and a further previous estimation for said clock phase offset is obtained, wherein the time interval between the current measurement epoch and second earlier epoch is at least T1. The difference between the computed clock phase offset differences is derived, and compared with a given threshold value. If the latter difference is greater than the given threshold value, an integrity risk signal is generated and transmitted to other devices for position determination.

Abstract: In a method for reducing the adverse effect of clock frequency jumps on a user-position determination device in a global navigation system, a plurality of space vehicles each having a clock, transmit position determination information to the position determining device. If a sufficient number of such navigation signals from a first group of space vehicles having clocks in which no jump occurs are available for this purpose, and if a calculated integrity risk is acceptable, position determination is performed using those navigation signals. If not, however, the position determination device receives navigation signals from space vehicles of a second group with clocks in which jumps can occur. The latter signals are combined with signals from the first group in a manner which takes into account possible jumps, and the process is repeated.

Abstract: A method for detecting frequency jumps of a navigation satellite's master clock, comprising the steps of i) monitoring the master clock signal that is generated by a master clock onboard of the satellite for a frequency jump, and ii) signaling a detected frequency jump of the master clock signal,

Abstract: In a method for providing integrity information for users of a global navigation system, which comprises several space vehicles like satellites transmitting information to a device for position detection, the transmitted information comprises first information from the global navigation system about the accuracy of a signal in space error SISE of a faulty space vehicle, and second information whether or not the global navigation system assesses the faulty space vehicle as faulty. The invention is based on the assumption how exact a fault can be detected, so that performance the global navigation system can be increased; and no unfounded assumption is used which improves the quality of service.