Time-Frequency and ISAR Characteristics of Wind Turbines with Higher Order Motions

Radar features from higher order motions of a wind turbine undergoing rotation are studied. Mathematical models for the motions are proposed and used to simulate the joint time-frequency (JTF) and inverse synthetic radar aperture (ISAR) characteristics of the motions. The motions are studied for an isolated turbine as well as for a turbine rotating above a ground. Selected motions are corroborated by laboratory model measurements.