Abstract: A device for detection of falsified signals in a satellite navigation system includes at least two antennas having one or more receivers for receiving navigation signals, a phase difference measuring unit for determining phase differences of the received navigation signals for each antenna, and a detection unit for detecting falsified navigation signals among the received navigation signals on the basis of the phase differences determined.

Abstract: A method for determining the integrity risk at an alert limit of a position solution determined with a satellite navigation system involves calculating a first integrity risk at the alert limit assuming that one satellite j of the satellites is faulty. A first position solution is determined with the signals from all of the satellites and a second position solution is determined with the signals from all of the satellites except for the signal received from the satellite j. A difference between the first and the second position solution is identified and subtracted from the alert limit to create a reduced alert limit. A second integrity risk at the reduced alert limit is calculated with the signals received from all satellites except the signal received from the satellite j. The integrity risk at the alert limit is determined using the minimum of the first and second integrity risks.

Abstract: In a satellite-based augmentation system a data stream is generated that includes user messages having different message types. A plurality of predetermined unique sequences of message types are formed and each formed sequence is allocated to one of a plurality of data sources that are used for generating user messages in the satellite-based augmentation system. A data source is selected for generating a data stream that includes user messages. The selected data source generates the data stream including user messages by using the predetermined unique sequence of message types that is allocated to the selected data source.

Abstract: In a satellite-based augmentation system a data stream is generated that includes user messages having different message types. A plurality of predetermined unique sequences of message types are formed and each formed sequence is allocated to one of a plurality of data sources that are used for generating user messages in the satellite-based augmentation system. A data source is selected for generating a data stream that includes user messages. The selected data source generates the data stream including user messages by using the predetermined unique sequence of message types that is allocated to the selected data source.

Abstract: A method for determining the integrity risk at an alert limit of a position solution determined with a satellite navigation system involves calculating a first integrity risk at the alert limit assuming that one satellite j of the satellites is faulty. A first position solution is determined with the signals from all of the satellites and a second position solution is determined with the signals from all of the satellites except for the signal received from the satellite j. A difference between the first and the second position solution is identified and subtracted from the alert limit to create a reduced alert limit. A second integrity risk at the reduced alert limit is calculated with the signals received from all satellites except the signal received from the satellite j. The integrity risk at the alert limit is determined using the minimum of the first and second integrity risks.

Abstract: A device for detection of falsified signals in a satellite navigation system includes at least two antennas having one or more receivers for receiving navigation signals, a phase difference measuring unit for determining phase differences of the received navigation signals for each antenna, and a detection unit for detecting falsified navigation signals among the received navigation signals on the basis of the phase differences determined.

Abstract: A method and apparatus for determining protection levels in a satellite navigation system includes the following steps: (1) determining an integrity risk at the alert limit for a plurality of application situations—for example, starting from approaches in category I (Category I precision approach) up to the operation “oceanic enroute;” (2) determining an interval of the alert limits between the largest set of alert limits which produces too high an integrity risk, and the smallest set of alert limits which produces an acceptable integrity risk; and (3) carrying out an interval nesting for the interval of the alert limits that was determined in the previous step, the integrity risk between the horizontal and the vertical being divided in the same way as it is obtained from the relationship between these integrity risks in the largest set of alert limits.

Abstract: In a vehicle, a vehicle system is provided that includes a position determination module for determining the position of the vehicle using an estimation of the error of satellite signals which are received by an earth-based receiver system, and an integrity module for determining an integrity risk for the position data for a vehicle, the risk being derived using time determinations performed by a satellite navigation system. When a threshold value for the integrity risk for the position data is exceeded, the vehicle system generates a warning signal which, by means of modules that are connected to the vehicle system, is designed to prevent the use of the position data for the vehicle. The integrity risk is determined using an estimated value for the error in the received satellite signal, and the receiver system functionally interacts with a plurality of satellites to determine and transmit data to a vehicle system containing a position determination module for determining the position of the vehicle.

Abstract: In a method for optimization of status messages in a satellite navigation system, which comprises a space segment having a plurality of satellites that emit navigation signals to be received and evaluated by utilization systems for position determination, and a ground segment having a plurality of observation stations that monitor the satellites, a threshold value is determined, as a function of location, for a message indicating that the error of a satellite is no longer acceptable.

Abstract: In a vehicle, a vehicle system is provided that includes a position determination module for determining the position of the vehicle using an estimation of the error of satellite signals which are received by an earth-based receiver system, and an integrity module for determining an integrity risk for the position data for a vehicle, the risk being derived using time determinations performed by a satellite navigation system. When a threshold value for the integrity risk for the position data is exceeded, the vehicle system generates a warning signal which, by means of modules that are connected to the vehicle system, is designed to prevent the use of the position data for the vehicle. The integrity risk is determined using an estimated value for the error in the received satellite signal, and the receiver system functionally interacts with a plurality of satellites to determine and transmit data to a vehicle system containing a position determination module for determining the position of the vehicle.

Abstract: A method and apparatus for determining protection levels in a satellite navigation system includes the following steps: (1) determining an integrity risk at the alert limit for a plurality of application situations—for example, starting from approaches in category I (Category I precision approach) up to the operation “oceanic enroute;” (2) determining an interval of the alert limits between the largest set of alert limits which produces too high an integrity risk, and the smallest set of alert limits which produces an acceptable integrity risk; and (3) carrying out an interval nesting for the interval of the alert limits that was determined in the previous step, the integrity risk between the horizontal and the vertical being divided in the same way as it is obtained from the relationship between these integrity risks in the largest set of alert limits.

Abstract: A satellite system for providing a navigation service includes a ground segment and a user segment. The ground segment provides information to enable the user segment to autonomously determine the user position performance.

Abstract: A method for determining overbounds comprises the steps of determining conservative overbounds (qi) of at least one error (?i) in a first phase space, multiplying the conservative overbounds (qi) of errors (?i) in the first phase space by a first parameter (?(?x)·2) and a second parameter (?(x)·2), and determining an upper bound for the integrity risk at the alert limit (pw,int(AL)) in a second phase space using overbounds (qi) of errors (?i) in the first phase space by the first parameter (?(?x)·2) and the second parameter (?(x)·2).

Abstract: Process for transmitting status messages to user terminals of a satellite data transmission system that transmits data formed as navigation blocks. The process includes reserving at least one selected data area in the navigation data blocks, splitting status messages into status data blocks that are smaller than the navigation data blocks, inserting the status data blocks into consecutive reserved data areas of the navigation data blocks and inserting, when the status messages are modified, modification message data blocks into subsequent reserved data areas of the navigation data blocks in place of one or more status data blocks of the status messages. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: Method for the transmission of navigation data to user terminals of a satellite navigation system composed of navigation satellites and pseudolites. The method includes transmitting positional information for at least one of the pseudolites, as part of the navigation data, without the use of separate channels or protocols for the transmission of the positional information for the at least one pseudolite. The positional information is transmitted in the form of a model of a pseudolite trajectory in a reference coordinate system which the model accounts for orbit-divergent motions of the at least one pseudolite, and the positional information for the at least on pseudolite forms a part of the navigation data.

Abstract: Process for transmitting status messages to user terminals of a satellite data transmission system that transmits data formed as navigation blocks. The process includes reserving at least one selected data area in the navigation data blocks, splitting status messages into status data blocks that are smaller than the navigation data blocks, inserting the status data blocks into consecutive reserved data areas of the navigation data blocks and inserting, when the status messages are modified, modification message data blocks into subsequent reserved data areas of the navigation data blocks in place of one or more status data blocks of the status messages. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.