Wind turbines usually cause significant interference in the conventional radar operations which might degrade the detection capabilities. Wind turbines do not only block the radar beam focusing on a specific target, thus creating shadowing effects, but also impose Doppler spectra contamination due to the continuous blade rotation. Therefore in order to identify, detect and possibly mitigate the presence of Wind Turbine Clutter (WTC), fundamental features of the blades rotation need to be estimated, such as rotation (angular) velocity. This information can be directly extracted by initially evaluating the angular displacement of the blades between successive radar measurements. In this paper, a method to estimate this rotation angle is proposed which is based on both radar polarimetry and estimation theory.