Railway positioning method and system

Abstract

A railway positioning method, based on the movement of a train determined by a signal receiver of a satellite navigation system embedded onboard the train, and on the movement of the train determined by an odometer embedded onboard the train, and a map of the railway tracks, by determination of the ionospheric propagation bias corresponding to a propagation bias of the signal carrier phase of the satellite navigation system, comprises the steps of, by line of sight of the satellites of the navigation system: estimating the biased ionospheric drift by difference between an integrated Doppler term determined by the receiver and a biased estimation of the movement of the train by the odometer; estimating the odometer drift bias and the drift bias of the local clock of the receiver, by least squares resolution of the speed determined by the satellite navigation system, of the drift bias of the local clock of the receiver, and of the odometer drift bias; correcting the estimation of the ionospheric drift, by subtraction of the estimated odometer drift bias; and correcting the integrated Doppler term using the drift bias of the local clock of the receiver and the ionospheric drift bias, and correcting the pseudo-distance deviations using the ionospheric drift bias.