Anyone who has been in the cockpit of an airplane knows that the pilots have instruments that display the attitude of the aircraft (pitch, roll, yaw) relative to the surface of the earth. What most people don’t know is the basis behind these various instruments. In small planes, the attitude is determined by simple mechanical gyroscopes. In most corporate and commercial aircraft, information on the attitude of the aircraft is generated by the Inertial Navigation System (INS) which uses accelerometers and gyroscopes to detect the motion of the aircraft. (more information can be found here: http://en.wikipedia.org/wiki/Inertial_navigation_system).

The following article from Stanford shows how research is being done to test the reliability of using multiple GPS receivers to determine the attitude of the airplane. This method uses the pseudo-inverse of a system of equations to solve for the positions of the receivers relative to the signals from 4 GPS satellites (which forms the basis of GPS navigation). The accuracy of this pseud0-inverse (and containment of singularities) will determine whether or not this system is a viable replacement to expensive INS systems in use today. Obviously, the error rate must be minimized in order to assure the safety and feasibility of a GPS based attitude system.

GPS-BASED ATTITUDE FOR AIRCRAFT