A sensor assembly (10, 30) for measuring an angular position of a rotatable structure (16,36) comprising: an annular ring (12, 32) that is eccentrically rotatable about an axis; first and second sensors (14, 34) arranged to be, in use, fixed relative to the rotatable structure (16,36) and rotatable relative to the annular ring (12, 32), the first and second sensors (14, 34) arranged to be disposed a predetermined angular distance from one another around the axis, and a predetermined distance from the axis, such that rotation of the annular ring (12, 32) relative to the first and second sensors (14, 34) causes a change in the distance from the annular ring (12, 32) to the first and second sensors (14, 34), the first and second sensors (14, 34) have a first and second output level, respectively, that is proportional to the distance of the first and second sensors (14, 34) respectively, from the annular ring (12, 32); and a sensor transducing circuit (22,42) arranged to: determine a weighting factor proportional to an absolute value of the first output level, such that the weighting of the second output level increases as the absolute value of the first output level approaches a relative peak value (50a, 50b); and proportionally combine the first and second output levels into an output signal (24, 44) based upon the weighting factor, the output signal (24, 44) indicating the angular position of the annular ring (12, 32) relative to the rotatable structure (16, 36). an annular ring (12, 32) that is eccentrically rotatable about an axis; first and second sensors (14, 34) arranged to be, in use, fixed relative to the rotatable structure (16,36) and rotatable relative to the annular ring (12, 32), the first and second sensors (14, 34) arranged to be disposed a predetermined angular distance from one another around the axis, and a predetermined distance from the axis, such that rotation of the annular ring (12, 32) relative to the first and second sensors (14, 34) causes a change in the distance from the annular ring (12, 32) to the first and second sensors (14, 34), the first and second sensors (14, 34) have a first and second output level, respectively, that is proportional to the distance of the first and second sensors (14, 34) respectively, from the annular ring (12, 32); and a sensor transducing circuit (22,42) arranged to: determine a weighting factor proportional to an absolute value of the first output level, such that the weighting of the second output level increases as the absolute value of the first output level approaches a relative peak value (50a, 50b); and proportionally combine the first and second output levels into an output signal (24, 44) based upon the weighting factor, the output signal (24, 44) indicating the angular position of the annular ring (12, 32) relative to the rotatable structure (16, 36). determine a weighting factor proportional to an absolute value of the first output level, such that the weighting of the second output level increases as the absolute value of the first output level approaches a relative peak value (50a, 50b); and proportionally combine the first and second output levels into an output signal (24, 44) based upon the weighting factor, the output signal (24, 44) indicating the angular position of the annular ring (12, 32) relative to the rotatable structure (16, 36).