Abstract: A process for increasing the availability of a global navigation system that includes a plurality of spacecraft, each of which transmits information for determining the position of a terminal. From the plurality of spacecraft, a first subset, with at least one spacecraft, and a second subset are determined, the second subset being constituted by those spacecraft that are not included in the first subset. The integrity risk is determined for the information transmitted only by the second spacecraft. The first and the second subsets of spacecraft are determined such that the integrity risk, for information transmitted by the second subset spacecraft minimized relative to the integrity risk for information of all spacecraft included in the plurality of spacecraft.

Abstract: A device and method for orbit prediction of satellites are provided. An accelerometer measures non-gravity forces acting on a satellite. A processor receives measured non-gravity forces from the accelerometer, estimates the contributions of the measured non-gravity forces to the movement of the satellite, and predicts the orbit of the satellite based on the estimated contributions of the non-gravity forces to the movement of the satellite.

Abstract: A process for improving continuity in a two-frequency navigation satellite system includes steps of i) observing the ionosphere by measurements in the two or more frequency bands; and ii) transmitting an alert message which informs user systems of a change of the ionosphere when at least one measurement indicates a change of the ionosphere that deviates from one or more predefined conditions.

Abstract: Methods and apparatus for implementing a receiver autonomous integrity monitoring (RAIM) algorithm are provided. The RAIM algorithm is for determining an integrity risk in a global navigation satellite system (GNSS) by processing several ranging signals received from satellites of the GNSS. The algorithm involves determining several integrity risks at an alert limit for different fault conditions of the ranging signals, and determining an overall integrity risk at the alert limit from the determined several integrity risks.

Abstract: For integrity communication, a navigation satellite system has a space segment with satellites that emit navigation signals for reception and analysis by user systems, and a ground segment with observation stations that monitor the satellites. The ground segment controls cause distribution of integrity information concerning the satellites to user systems with the navigation signals. The integrity information has a first SISMA value and a second broadcast SISMA value for the accuracy of the satellite monitored by the ground segment. The second broadcast SISMA value takes into account a failure of an observation station of the ground segment, and a threshold value for the second broadcast SISMA value is provided. The threshold value with the integrity information for a satellite is transmitted instead of the second broadcast SISMA value when the latter exceeds the threshold value and the first SISMA value is lower than the threshold value for the satellite.

Abstract: A device of a supplementary navigation satellite is provided. The device includes a unit for generating navigation signals, the signal strength of the navigation signals being dimensioned in such a way that it is still possible to receive signals of other satellite navigation systems.

Abstract: Embodiments of the invention are directed to a method for integrity communication in a satellite navigation system having a space segment with several satellites transmitting navigation signals for reception and evaluation by use systems for position determination, and a ground segment with several observation stations that, in their totality, monitor the satellites and their signals, and including at least one transmitting station.

Abstract: A method for monitoring the integrity of satellite navigation system includes a first detection of integrity problems, in which the same entity of a navigation signal from a particular satellite is received at different sites, and evaluated to estimate the error of the entity and the error made during the error estimation process. In a second detection, navigation signals received from a specific satellite are measured and evaluated to estimate the error of the entity and the error in the error estimation process. Finally, in a third detection, several navigation signals from different satellites are measured, and evaluated to estimate the error of the entity and the error made in the error estimation process. Integrity problems which are detectable in the first and second detections are taken into account only if it is probable that they occur during the third detection, and have not been discovered during the first and second detection.

Abstract: In a system for characterizing a satellite clock in a satellite, the satellite has a transmitting device that emits a transmission signal at a transmission frequency indicative of a state of the satellite clock, and a receiver clock which has a higher precision than the satellite clock. A receiving device is configured to receive the transmission signal and to determine a received signal therefrom, as well as a received signal frequency and/or phase, using the receiver clock. Finally, an evaluation device is configured to determine a frequency offset, drift, and/or an Allan deviation of the transmission frequency from the received signal frequency and/or the received signal phase. The evaluation device determines the stability of the satellite clock, or the validity of its time indication, from the determined frequency offset, frequency drift, and/or the Allan deviation, to thereby characterize the satellite clock.

Abstract: In a method of improving the integrity communication in a satellite navigation system which comprises a space segment having multiple satellites which emit navigation signals for the reception and evaluation by use systems for position determination, and a ground segment having several observation stations which monitor the satellites, an error budget for different observation stations or groups of observations stations is transmitted with the navigation signal of a satellite. The navigation signal is received and an error budget contained therein is evaluated by computing a scalar value from the error budget. The scalar value indicates the precision of the error estimate for the generation of the navigation signal.

Abstract: Methods and apparatus of determining an integrity risk of a satellite reference system are provided. Galileo parameters according to the Galileo integrity concept are detected. The Galileo parameters are imaged onto satellite based augmentation system (SBAS) parameters used in the SBAS. The integrity risk of the satellite reference system is determined according to the SBAS integrity concept using the SBAS parameters.

Abstract: A method for estimating an integrity risk in a satellite navigation system includes receiving a plurality of navigation signals at a user system from at least one satellite, the plurality of navigation signals including data relative to the integrity of the satellite navigation system; and estimating the integrity risk using the data in the at least one user system. The estimating further includes forming a plurality of intervals of an integration variable of an integral function, estimating a maximum of the integrity risk for each interval, comparing the maximum of each interval to find an overall maximum of all the intervals; and using the overall maximum as an estimate of the integrity risk.

Abstract: A method for transmitting additional information in a satellite navigation system includes providing a navigation message including a continuous data stream having a prescribed bit rate and structuring the navigation message in a plurality of pages generated according to a prescribed page definition so as to transmit information, wherein each of the plurality of pages includes a checksum calculated as a function of information contained in the page. The method further includes generating at least one new page containing the additional information so as to form a changed, navigation message according to a further page definition that differs from the prescribed page definition such that the checksum calculated as a function of information contained on the page generated according to the prescribed page definition is false; and transmitting the at least one new page.

Abstract: A method for transmitting additional information in a satellite navigation system includes providing a navigation message having a plurality of parameters, selecting at least one parameter from the plurality of parameters for the transmitting of the additional information, replacing the at least one parameter, at least partially, by the additional information so as to form a changed navigation message, and sending the changed navigation message

Abstract: An arrangement for transmitting information concerning an operating condition of a vehicle, such as an aircraft or spacecraft, exerts tactile stimuli as information via a stimulus generator on at least one operator of the vehicle. The stimulus is exerted on a sense organ or body part of the operator that is not used for active transmission of information during trouble-free and proper operation of the vehicle.

Abstract: A process for increasing the availability of a global navigation system that includes a plurality of spacecraft, each of which transmits information for determining the position of a terminal. From the plurality of spacecraft, a first subset, with at least one spacecraft, and a second subset are determined. the second subset being constituted by those spacecraft that are not included in the first subset. The integrity risk is determined for the information transmitted only by the second spacecraft. The first and the second subsets of spacecraft are determined such that the integrity risk, for information transmitted by the second subset spacecraft minimized relative to the integrity risk for information of all spacecraft included in the plurality of spacecraft.

Abstract: For integrity communication, a navigation satellite system has a space segment with satellites that emit navigation signals for reception and analysis by user systems, and a ground segment with observation stations that monitor the satellites. The ground segment controls cause distribution of integrity information concerning the satellites to user systems with the navigation signals. The integrity information has a first SISMA value and a second broadcast SISMA value for the accuracy of the satellite monitored by the ground segment. The second broadcast SISMA value takes into account a failure of an observation station of the ground segment, and a threshold value for the second broadcast SISMA value is provided. The threshold value with the integrity information for a satellite is transmitted instead of the second broadcast SISMA value when the latter exceeds the threshold value and the first SISMA value is lower than the threshold value for the satellite.

Abstract: Methods and apparatus of determining an integrity risk of a satellite reference system are provided. Galileo parameters according to the Galileo integrity concept are detected. The Galileo parameters are imaged onto satellite based augmentation system (SBAS) parameters used in the SBAS. The integrity risk of the satellite reference system is determined according to the SBAS integrity concept using the SBAS parameters.

Abstract: A navigation system automatically determines one or more bypass routes for a vehicle, based on a continuously determined vehicle position, according to a process having the following steps: receiving data concerning a hindrance in a region in the proximity of a current position; automatically determining one or more destinations which can be reached via the region affected by the hindrance; automatically determining additional regions via which the determined destinations can be reached; calculating an evaluation factor for each of the determined additional regions; and automatically determining one or more routes for bypassing the region affected by the hindrance, based on the evaluation factor.

Abstract: A method of automatically determining a landing runway for an aircraft includes the steps of i) determining control points assigned to a landing runway along a landing approach of an airplane; ii) determining the spatial deviation of the airplane from the determined control points; and iii) determining an appropriate landing runway while taking into account the determined spatial deviation.