A wind turbine includes a hub configured to rotate about an axis at a first rotation speed and at least one blade coupled to the hub. The wind turbine also includes a sensor assembly configured to detect at least one characteristic of wind flowing through the wind turbine. The sensor assembly is mounted to the hub. The sensor assembly includes a laser device configured to emit a laser beam and at least one optical element configured to direct the laser beam. The sensor assembly also includes a non-motorized mechanism configured to rotate the at least one optical element at a second rotation speed when the hub rotates at the first rotation speed. The second rotation speed is greater than the first rotation speed.