Atmosphere is quite gentle in infrared band with respect to lower wavelengths. Around 80% wavefront phase variance is contained by overall tip-tilt error. So, improvement of image quality is possible just correcting overall tip-tilt. In NIPI system, quadrant detector is used to detect image motion and required tilt is given to tip-tilt mirror's actuators to stabilise image motion in real time in close loop. In this case target object is used as guide star, to detect its motion which is wavefront tip-tilt.