Patent ID: 9041594
Filing Date: 2015-05-26
Classification: G01S

Abstract:
1. A method comprising: directing a plurality of RF beams toward a group of rotating blades of a helicopter blade assembly, the plurality of RF beams directed transverse to a rotation plane of the group of rotating blades so as to be directed generally orthogonal to a chord of the rotating blades; placing a plurality of RF based sensor antennas in respective positions to detect a reflected RF beam from the group of rotating blades, each sensor antenna of the plurality of sensor antennas placed to receive a reflected beam from a respective RF beam of the plurality of RF beams; detecting the presence, absence, or position of the group of rotating blades with respect to the plurality of sensor antennas; tracking timing of the presence, absence, and crossing of each of blade of the group of rotating blades over a center line of each of the plurality of sensor antennas based on the detected presence, absence, or position of the group of rotating blades; and transmitting information related to the presence and absence of the blades.