Abstract: In a system for characterizing a satellite clock in a satellite, the satellite has a transmitting device configured to emit a transmission signal at a transmission frequency as a function of a state of the satellite clock. The system includes a receiver clock which has a higher precision than the satellite clock. In addition, 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 provided which 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 operation of the satellite clock or the validity of the time indication of the satellite clock from the determined frequency offset, frequency drift, and/or the Allan deviation, to thereby characterize the satellite clock.

Abstract: A process, a satellite navigation system and a user terminal for furnishing and transmitting navigation data in a navigation system by transmitting several navigation data blocks from a navigation data transmission unit to navigation terminals. Before transmitting the navigation data to the navigation device, an interleaving of at least two navigation data blocks takes place.

Abstract: In a method for adjusting the integrity alert threshold in a satellite navigation system, an alert message for a satellite is sent when an estimated signal error of the satellite signal emitted by the satellite is greater than a defined integrity alert threshold. According to the invention one or more parameters in a data stream emitted by the satellite are varied, and the integrity alert threshold is adjusted based on the changed parameters.

Abstract: In a method for relative time and position determinations for moving objects of a constellation, signals by the objects are isochronously transmitted, with each object transmitting a unique signal for that object. The received signals of each object of the constellation are transmitted to all other objects of the constellation after a predetermined waiting time.

Abstract: A method for providing and transmitting data in a data transmission system by transmitting several data blocks from a data-transmitting device to terminals. Before transmission of the data to the terminals an interleaving process of at least two data blocks is conducted. For the purpose of interleaving for each data unit of the data blocks, a transmission time is established with the help of an algorithm in such a way that for the transmission of k time critical data blocks with k=2, 3, 4, . . . and for one non-time critical data block, the transmission times of the data units of each time critical data block are respectively set at a fraction 1/k of the transmission time of the non-critical data block.

Abstract: A process, a satellite navigation system and a user terminal for furnishing and transmitting navigation data in a navigation system by transmitting several navigation data blocks from a navigation data transmission unit to navigation terminals. Before transmitting the navigation data to the navigation device, an interleaving of at least two navigation data blocks takes place.