Abstract: Method for determining structural parameters of a railway track having a sensor array, includes measuring vertical and/or lateral irregularities of the rail with the sensor array along the rail, thereby providing signals corresponding to geometrical irregularities at different distance from the wheel-load. A model is provided describing the rail's deflection shape, which is dependent on structural parameters of the rail and on the loads on the rail. The model is stored in a processor where geometrical irregularities are compared under different load influence for generating a measured deflection shape. At least one theoretical rail deflection shape is generated using the model by varying structural parameters and the load in the model. At least one of theoretical deflection shapes is compared with the measured deflection shape for each point of the rail, and the structural parameters of that theoretical deflection shape which best matches the measured deflection shape are determined.

Abstract: A method for establishing the deflection and/or the stiffness of a supporting structure which is subjected to a load. The method includes the steps of moving a measurement vehicle along the supporting structure, the vehicle having a loaded axle, a first measuring system being a first versine system and a second measuring system being one of an inertia based system and a second versine system. At a predetermined sampling rate, two sets of levels are measured using the two measuring systems. The two sets of levels are converted or transformed such that they relate to the same reference system and, thereafter, for each pair of sampled levels, the difference between the two levels is calculated such that the contribution to the measurements originating from unloaded irregularities in the supporting structure is eliminated, whereafter the deflection and/or the stiffness of the supporting structure is established from the calculated difference.

Abstract: A method and device for determining at least a first parameter of a track. The method includes providing a first track geometry quality data associated to at least one point along a rail at a first temperature, providing a second track geometry quality data associated to at least one point at a second temperature, and describing a difference between the first and second track geometry quality data using a model. The model relates the first and second track geometry quality data with associated temperatures to stress free temperature and/or track resistance, and estimates the stress free temperature and/or track resistance in at least one point based on the model.