The present invention provides a new set of algorithmic solutions to
accommodate track inaccuracy information in track databases. Navigation
and measurement aiding processes are defined by a stochastic mode
relative to a moving rail frame defined so that it is aligned with the
heading of the compensated track database at the current along
track-position. Filtering generates long and short wavelength track
alignment disturbances commensurate with track grade to compensate for
track database errors; a stochastic error model is defined as the
difference between the deterministic implementation and the actual
stochastic processes Bayesian estimation of the error variables is
implemented via a digital Kalman filter with the navigation, database,
and measurement errors removed by subtracting the filter estimates.