Abstract: A method for selecting usable satellites from among the satellites of a localization constellation, to determine an instantaneous kinematic state of a train, is provided. The method includes determining a measured value and an estimated value of a Doppler coefficient and/or a pseudo-range, then comparing the measured and estimated values and, in case of divergence, deleting the satellite from the usable satellites. The estimated value results from a dynamic model of the train, which uses only a kinematic state at a past moment to calculate an estimated instantaneous kinematic state and that uses a mapping of the track on which the guided vehicle moves.

Abstract: A method for selecting usable satellites from among the satellites of a localization constellation, to determine an instantaneous kinematic state of a train, is provided. The method includes determining a measured value and an estimated value of a Doppler coefficient and/or a pseudo-range, then comparing the measured and estimated values and, in case of divergence, deleting the satellite from the usable satellites. The estimated value results from a dynamic model of the train, which uses only a kinematic state at a past moment to calculate an estimated instantaneous kinematic state and that uses a mapping of the track on which the guided vehicle moves.

Abstract: A system for establishing the speed, in a safe manner, of an object (1) which is travelling along a known trajectory, including a device (3, 7) for locating the object and direction of its movement, a receiver (6) for receiving a signal from a plurality of satellites (4, 5) and processing units. For each satellite, a processing unit (8) includes a frequency meter for measuring the frequency shift of the signal received relative to the frequency of the signal transmitted, a device for establishing the vectorial difference of the speeds of the object and the satellite by calculating the Doppler effect and, a calculator of the speed in the movement direction of the object. The measurements of the frequency shift are repeated independently on signals from a plurality of satellites, and the results obtained are combined in order to obtain a speed with the desired level of safety.

Abstract: The invention relates to a system for establishing the speed, in a reliable manner, of an object (1) which is travelling along a known trajectory, comprising: means (3, 7) for locating the object and direction of its movement, means (6) for receiving a signal from a satellite (4, 5) and calculation means (8) comprising: means for measuring the frequency shift of the signal received relative to the frequency of the signal transmitted, means for establishing the vectorial difference of the speeds of the object and the satellite by calculating the Doppler effect and, means for calculating the speed in the movement direction of the object, and, the measurements of the frequency shift being repeated independently on signals from a plurality of satellites, means for combining the results obtained in order to obtain a speed with the desired level of reliability.