Abstract: A wind turbine rotor comprising a hub with a rotor blade mounted to a bearing of the hub wherein the rotor blade has a longitudinal axis extending in a radial direction relative to an axis of rotation of the hub, and the rotor blade is rotatable about its longitudinal axis whereby the pitch of the rotor blade is adjustable, The rotor blade has a tag such as an RFID tag fixed on the rotor blade at a predetermined angular position about the longitudinal axis of the rotor blade; and a sensor is fixed on the hub for contactless sensing of the tag when the tag is in a predetermined angular position about the longitudinal axis of the rotor blade. Repeated and accurate calibration of rotor blade pitch is hereby made possible.

Abstract: The invention relates to a method of registering events in a wind power system comprising at least two data processors, wherein the data processors of said wind power system are mutually time synchronized, wherein events are registered in said at least two data processors, wherein the timing of said events registered in different of said at least two data processors is established according to said time synchronization. According to an advantageous embodiment of the invention, events may be registered and preferably analyzed according to a common timing. This analyzing makes it possible to establish an analysis where events of different wind turbines are basically interrelated and where information regarding such interrelation is important or crucial for establishment of control or fault detection based on correctly timed events from different wind turbines.