Multipath-dominant analysis of rotating blades using a pulsed waveform

Wind turbines present an opportunity for real-time, clear weather wind observations. By remotely measuring the speed and direction of turbine rotation, one could opportunistically measure wind speed and direction. However, current methods do not allow for rotation direction measurement if one uses a stationary monostatic radar platform. The authors present a novel angular fingerprinting algorithm that fills this gap. Unlike other approaches, the authors assume that the target´s centroid is stationary and exploit doppler multipath signals to resolve the otherwise unavoidable ambiguities that arise. Since the algorithm is based on an underlying differential topological theory, it is robust to distortions in the collected data. The authors demonstrate performance of this algorithm experimentally, by exhibiting a pulsed doppler sonar collection system that runs on a smartphone.