Estimation of lateral track irregularity using a Kalman filter. Experimental validation

•A simple and robust method for lateral track alignment estimation is presented.•The method is based on a measuring system combined with a Kalman filter estimator.•The method has been experimentally validated in a 1:10 scaled track facility.•Results have been analysed in the different wavelength ranges defined in standards.•Results of the estimation show very good agreement with experiments.