In this work, the altitude control of a quadrotor unmanned aerial vehicle is treated using its altitude dynamics in hover mode. Due to persistent aerodynamic disturbances, the control of a quadrotor unit is cumbersome; especially, the ground wake effect which comes into play during landing. In this work, an Active Disturbance Rejection and Optimal Controller (ADROC) modified from an Active disturbance rejection controller (ADRC) is proposed to compensate for undesirable effects resulting in smoother control. The adaptation of the ADRC controller is governed by a Least-Means-Square (LMS) algorithm on the extended state observer (ESO). The ESO linearizes the system and finally, an LQR policy is utilized to find optimal control signal for landing and take-off of the quadrotor.