Signal amplification in blade angle position feedback system

A method for providing feedback for an aircraft-bladed rotor, the rotor rotatable about a longitudinal axis and having blades with adjustable blade pitch angle, the method comprising:

• receiving at least one sensor signal from at least one sensor positioned adjacent a feedback device coupled to rotate with the rotor and to move along the longitudinal axis with adjustment of the blade pitch angle, the feedback device comprising a core, at least one first position marker affixed to the core and extending along a direction angled relative to the longitudinal axis, and a plurality of second position markers affixed to the core and extending substantially parallel to the axis, the core and the plurality of second position markers made of a first material having a first magnetic permeability and the at least one first position marker comprising a second material having a second magnetic permeability greater than the first magnetic permeability, the at least one sensor signal produced by the at least one sensor in response to detecting passage of the at least one first position marker and the plurality of second position markers as the feedback device rotates about the longitudinal axis;
• and
• processing, at a control unit communicatively coupled to the at least one sensor, the at least one sensor signal to generate a feedback signal indicative of the blade pitch angle of the rotor.