Monitoring of wind direction measurements in wind parks

A method for monitoring a validity of a calibration of a system parameter, wherein a calibrated system parameter is generated based on the calibration by each of a plurality of spatially associated wind turbines of a wind park, wherein the plurality of spatially associated wind turbines comprises a first wind turbine and a second wind turbine, the method comprising:

• subtracting from a first signal representing the calibrated system parameter measured at the first wind turbine a second signal representing the calibrated system parameter measured by the second wind turbine to generate a difference signal, wherein the first signal and the second signal represent the same calibrated system parameter;
• processing the difference signal by a function based on a stochastic model to generate a decision data signals;
• and
• determining, based on the decision data signal, if the calibrated system parameter of at least one of the first wind turbine and the second wind turbine is based on an invalid calibration.