A method for establishing the rotor angle of a synchronous machine. The method includes determining a first estimated value for the d-axis of the synchronous machine, feeding at least one refinement voltage pulse pair into the stator of the synchronous machine, the refinement voltage pulse pairs each distanced from the first estimated value for the d-axis of the synchronous machine by the same angular value in different directions, detecting the angle-dependent refinement current responses to the refinement voltage pulses, determining the angle-dependent refinement phase differences on the basis of the respective detected refinement current response, determining first estimated curves on the basis of at least some of the angle-dependent refinement current responses, determining second estimated curves on the basis of at least some of the angle-dependent refinement phase differences. and determining a refined estimated value for the d-axis of the synchronous machine on the basis of the estimated curves.