The present disclosure provides a method and system of determining aerodynamic imbalances of a wind turbine rotor and optionally correcting such imbalances, as well as a method and system for determining mass imbalances of a wind turbine rotor and optionally correcting such imbalances. The aerodynamic imbalances may be detected and corrected using optical analysis of images of the wind turbine rotor. The mass imbalances may be detected and corrected using vibration analysis of the wind turbine rotor, typically using accelerometers or possibly other vibration sensors.