Bias error is reduced in a vibrating structure sensor having primary and secondary pick-offs separated by a fixed angular amount (45°) with respect to the vibrating structure by summing a proportion of the primary pick-off output signal into the secondary pick-off output signal or subtracting a proportion of the primary pick-off output signal from the secondary pick-off output signal effectively to reduce or increase the angular separation of the secondary pick-off from the primary driver by an amount sufficient to set the rate output signal from the vibrating structure to zero and thereby minimize bias error.