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.
