in the past few years, researchers have shown great interest in quadrotor aircraft as a platform for uav research due to simplicity of construction as well as maintenance, ability to hover in small indoor locations or hazardous environments, vertical take-off and landing capability, etc. attitude stabilization of a quadrotor requires accurate information about current orientation of the vehicle. with the emergence of micro-electro-mechanical system (mems) sensors, a relatively cost-effective way for attitude estimation consists of using gyroscope, accelerometer and magnetometer devices strapped down on vehicle’s center of mass. a number of previous works deal with fusing angular velocity with measurements of accelerometer and magnetometer to construct an estimation of aircraft orientation.